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This feature module describes the Frame Relay PVC Interface Priority Queueing (FR PIPQ) feature. It includes information on the benefits of this new feature, supported platforms, related documents, and so on.
This document includes the following sections:
The FR PIPQ feature provides an interface-level priority queueing scheme in which prioritization is based on destination permanent virtual circuit (PVC) rather than packet contents. For example, FR PIPQ allows you to configure a PVC transporting voice traffic to have absolute priority over a PVC transporting signalling traffic, and a PVC transporting signalling traffic to have absolute priority over a PVC transporting data.
FR PIPQ provides four levels of priority: high, medium, normal, and low. The Frame Relay packet is examined at the interface for the data-link connection identifier (DLCI) value. The packet is then sent to the correct priority queue based on the priority level configured for that DLCI.
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Note When using FR PIPQ, configure the network so that different types of traffic are transported on separate PVCs. FR PIPQ is not meant to be used when an individual PVC carries different traffic types that have different quality of service (QoS) requirements. |
You assign priority to a PVC within a Frame Relay map class. All PVCs using or inheriting that map class will be classed according to the configured priority. If a PVC does not have a map class associated with it, or if the map class associated with it does not have priority explicitly configured, then the packets on that PVC will be queued on the default "normal" priority queue.
If you do not enable FR PIPQ on the interface using the frame-relay interface-queue priority command in interface configuration mode, configuring PVC priority within a map class will not be effective. At this time you have the option to also set the size (in maximum number of packets) of the four priority queues.
FR PIPQ works with or without Frame Relay traffic shaping (FRTS) and FRF.12. The interface-level priority queueing takes the place of the FIFO queueing or dual FIFO queueing normally used by FRTS and FRF.12. PVC priority assigned within FR PIPQ takes precedence over FRF.12 priority, which means that all packets destined for the same PVC will be queued on the same interface queue whether they were fragmented or not.
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Note Although high priority PVCs most likely will transport only small packets of voice traffic, you may want to configure FRF.12 on these PVCs anyway to guard against any unexpectedly large packets. |
FR PIPQ provides four levels of PVC priority: high, medium, normal, and low. This method of queueing ensures that time/delay-sensitive traffic such as voice has absolute priority over signalling traffic, and that signalling traffic has absolute priority over data traffic, providing different PVCs are used for the different types of traffic.
The following restrictions apply to FR PIPQ:
The following features and technologies are related to FR PIPQ:
The following documents provide information related to FR PIPQ:
Standards
No new or modified standards are supported by this feature.
MIBs
No new or modified MIBs are supported by this feature.
For descriptions of supported MIBs and how to use MIBs, see the Cisco MIB web site on CCO at http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.
RFCs
No new or modified standards are supported by this feature.
The following prerequisites apply to FR PIPQ:
See the following sections for configuration tasks for the FR PIPQ feature. Each task in the list is identified as either optional or required:
To configure PVC priority within a map class, use the following commands beginning in global configuration mode:
| Command | Purpose | |
|---|---|---|
Step 1 | Router(config)# map-class frame-relay map-class-name | Specifies a Frame Relay map class. |
Step2 | Router(config-map-class)#frame-relay interface-queue
priority {high | medium | normal | low}
| Assigns a PVC priority level to a Frame Relay map class. |
To enable FR PIPQ and set the priority queue sizes, use the following commands beginning in global configuration mode:
| Command | Purpose | |
|---|---|---|
Step1 | Router(config)#interface type number [name-tag] | Configures an interface type and enters interface configuration mode. |
Step2 | Router(config-if)#encapsulation frame-relay [cisco | ietf] | Enables Frame Relay encapsulation. |
Step3 | Router(config-if)#frame-relay interface-queue priority [high-limit medium-limit normal-limit low-limit] | Enables FR PIPQ and sets the priority queue limits. |
To assign a map class to a specific PVC, use the following commands beginning in interface configuration mode:
| Command | Purpose | |
|---|---|---|
Step1 | Router(config-if)#frame-relay interface-dlci dlci | Specifies a single PVC on a Frame Relay interface. |
Step2 | Router(config-fr-dlci)#class map-class-name | Associates a map class with a specified PVC. |
To verify the configuration of FR PIPQ, use one or more of the following commands in privileged EXEC mode:
| Command | Purpose |
|---|---|
Router#show frame-relay pvc [interface interface][dlci] | Displays statistics about PVCs for Frame Relay interfaces. |
Router#show interfaces [type number][first][last] | Displays the statistical information specific to a serial interface. |
Router#show queueing [custom | fair | priority | random-detect [interface atm_subinterface [vc[[vpi/]vci]]]] | Lists all or selected configured queueing strategies. |
To monitor and maintain FR PIPQ, use one or more of the following commands in privileged EXEC mode:
| Command | Purpose |
|---|---|
Router#debug priority | Debugs priority output queueing. |
Router#show frame-relay pvc [interface interface][dlci] | Displays statistics about PVCs for Frame Relay interfaces. |
Router#show interfaces [type number][first][last] | Displays the statistical information specific to a serial interface. |
Router#show queue interface-name interface-number [vc [vpi/] vci][queue-number] | Displays the contents of packets inside a queue for a particular interface or VC. |
Router#show queueing [custom | fair | priority | random-detect [interface atm_subinterface [vc[[vpi/]vci]]]] | Lists all or selected configured queueing strategies. |
This section provides configuration examples for FR PIPQ.
This example shows the configuration of four PVCs on serial interface 0. DLCI 100 is assigned high priority, DLCI 200 is assigned medium priority, DLCI 300 is assigned normal priority, and DLCI 400 is assigned low priority.
The following commands configure Frame Relay map classes with PVC priority levels:
Router(config)#map-class frame-relay HI Router(config-map-class)#frame-relay interface-queue priority high Router(config-map-class)#exit Router(config)#map-class frame-relay MED Router(config-map-class)#frame-relay interface-queue priority medium Router(config-map-class)#exit Router(config)#map-class frame-relay NORM Router(config-map-class)#frame-relay interface-queue priority normal Router(config-map-class)#exit Router(config)#map-class frame-relay LOW Router(config-map-class)#frame-relay interface-queue priority low Router(config-map-class)#exit
The following commands enable Frame Relay encapsulation and FR PIPQ on serial interface 0. The sizes of the priority queues are set at a maximum of 20 packets for the high priority queue, 40 for the medium priority queue, 60 for the normal priority queue, and 80 for the low priority queue.
Router(config)#interface Serial0 Router(config-if)#encapsulation frame-relay Router(config-if)#frame-relay interface-queue priority 20 40 60 80
The following commands assign priority to four PVCs by associating the DLCIs with the configured map classes:
Router(config-if)#frame-relay interface-dlci 100 Router(config-fr-dlci)#class HI Router(config-fr-dlci)#exit Router(config-if)#frame-relay interface-dlci 200 Router(config-fr-dlci)#class MED Router(config-fr-dlci)#exit Router(config-if)#frame-relay interface-dlci 300 Router(config-fr-dlci)#class NORM Router(config-fr-dlci)#exit Router(config-if)#frame-relay interface-dlci 400 Router(config-fr-dlci)#class LOW Router(config-fr-dlci)#exit
This section documents new or modified commands. All other commands used with this feature are documented in the Cisco IOS Release 12.1 command reference publications.
To enable the Frame Relay PVC Interface Priority Queueing (FR PIPQ) feature, use the frame-relay interface-queue priority interface configuration command. To disable FR PIPQ, use the no form of this command.
frame-relay interface-queue priority [high-limit medium-limit normal-limit low-limit]To assign priority to a permanent virtual circuit (PVC) within a Frame Relay map class, use the frame-relay interface-queue priority map-class configuration command. To remove priority from a PVC within a Frame Relay map class, use the no form of this command.
frame-relay interface-queue priority {high | medium | normal | low}
Syntax Description
high-limit Size of the high priority queue specified in maximum number of packets. medium-limit Size of the medium priority queue specified in maximum number of packets. normal-limit Size of the normal priority queue specified in maximum number of packets. low-limit Size of the low priority queue specified in maximum number of packets. high Assigns high priority to a PVC. medium Assigns medium priority to a PVC. normal Assigns normal priority to a PVC. low Assigns low priority to a PVC.
Defaults
The default sizes of the high, medium, normal, and low priority queues are 20, 40, 60, and 80 packets, respectively.
When FR PIPQ is enabled on the interface, the default PVC priority is normal priority.
Command Modes
Interface configuration
Map-class configuration
Command History
12.1(2)T This command was introduced.
Release
Modification
Usage Guidelines
FR PIPQ must be enabled on the interface in order for the map-class configuration of PVC priority to be effective.
Before you configure FR PIPQ using the frame-relay interface-queue priority command, the following conditions must be met:
You will not be able to configure FR PIPQ if any queueing other than FIFO queueing is already configured at the interface level. You will be able to configure FR PIPQ when weighted fair queueing (WFQ) is in use, as long as WFQ is the default interface queueing method. Disabling FR PIPQ will restore the interface to dual FIFO queueing if FRF.12 is enabled, FIFO queueing if Frame Relay traffic shaping (FRTS) is enabled, or the default queueing method for the interface.
Examples
In the following example, FR PIPQ is enabled on serial interface 0, and the limits of the high, medium, normal, and low priority queues are set to 10, 20, 30, and 40 packets, respectively. PVC 100 is assigned high priority, so all traffic destined for PVC 100 will be sent to the high priority interface queue.
interface serial0 encapsulation frame-relay frame-relay interface-queue priority 10 20 30 40 frame-relay interface-dlci 100 class high_priority_class ! map-class frame-relay high_priority_class frame-relay interface-queue priority high
Related Commands
debug priority Displays priority queueing events. show frame-relay pvc Displays statistics about PVCs for Frame Relay interfaces. show interfaces Displays statistics for all interfaces configured on the router or access server. show queue Displays the contents of packets inside a queue for a particular interface or VC. show queueing Lists all or selected configured queueing strategies.
Command
Description
Syntax Description
interface (Optional) Indicates a specific interface for which PVC information will be displayed. interface (Optional) Interface number containing the data-link connection identifiers (DLCIs) for which you wish to display PVC information. dlci (Optional) A specific DLCI number used on the interface. Statistics for the specified PVC are displayed when a DLCI is also specified.
Defaults
No default behavior or values.
Command Modes
Privileged EXEC
Command History
10.0 This command was introduced. 12.0(1)T This command was modified to display statistics about virtual access interfaces used for PPP connections over Frame Relay. 12.0(3)XG This command was modified to include the fragmentation type and size associated with a particular PVC when fragmentation is enabled on the PVC. 12.0(4)T This command was modified to include the fragmentation type and size associated with a particular PVC when fragmentation is enabled on the PVC. 12.0(5)T This command was modified to include information on the special voice queue that is created using the queue keyword of the frame-relay voice bandwidth command. 12.1(2)T This command was modified to include information about the policy map attached to a specific PVC. The command was also modified to include information about the priority configured for a PVC within FR PIPQ.
Release
Modification
Usage Guidelines
Use this command to monitor the PPP link control protocol (LCP) state as being open with an "up" state, or closed with a "down" state.
When "vofr" or "vofrcisco" has been configured on the PVC, and a voice bandwidth has been allocated to the class associated with this PVC, configured voice bandwidth and used voice bandwidth are also displayed.
Statistics Reporting
To obtain statistics about PVCs on all Frame Relay interfaces, use this command with no arguments.
To obtain statistics about a PVC that include policy-map configuration or the priority configured for that PVC, use this command with the dlci argument.
Per-VC counters are not incremented at all when either autonomous or silicon switching engine (SSE) switching is configured; therefore, PVC values will be inaccurate if either switching method is used.
Traffic Shaping
Congestion control mechanisms are currently not supported, but the switch passes forward explicit congestion notification (FECN) bits, backward explicit congestion notification (BECN) bits, and discard eligible (DE) bits unchanged from entry to exit points in the network.
If a Local Management Interface (LMI) status report indicates that a PVC is not active, then it is marked as inactive. A PVC is marked as deleted if it is not listed in a periodic LMI status message.
Examples
The various displays in this section show sample output for a variety of PVCs. Some of the PVCs carry data only; some carry a combination of voice and data.
Frame Relay PVC Priority Queueing Example
The following is sample output for a PVC that has been assigned high priority:
ed2-36b# show frame-relay pvc 100 PVC Statistics for interface Serial0 (Frame Relay DTE) DLCI = 100, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0 input pkts 0 output pkts 0 in bytes 0 out bytes 0 dropped pkts 0 in FECN pkts 0 in BECN pkts 0 out FECN pkts 0 out BECN pkts 0 in DE pkts 0 out DE pkts 0 out bcast pkts 0 out bcast bytes 0 pvc create time 00:00:59, last time pvc status changed 00:00:33 priority high
Low Latency Queueing for Frame Relay Example
The following is sample output from the show frame-relay pvc command for a PVC shaped to a 64K committed information rate (CIR) with fragmentation. A policy map is attached to the PVC and is configured with a priority class for voice, two data classes for IP Precedence traffic, and a default class for best-effort traffic. Weighted Random Early Detection (WRED) is used as the drop policy on one of the data classes.
ed2-36b# show frame-relay pvc 100
PVC Statistics for interface Serial1/0 (Frame Relay DTE)
DLCI = 100, DLCI USAGE = LOCAL, PVC STATUS = INACTIVE, INTERFACE = Serial1/0.1
input pkts 0 output pkts 0 in bytes 0
out bytes 0 dropped pkts 0 in FECN pkts 0
in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
in DE pkts 0 out DE pkts 0
out bcast pkts 0 out bcast bytes 0
pvc create time 00:00:42, last time pvc status changed 00:00:42
service policy mypolicy
Class voice
Weighted Fair Queueing
Strict Priority
Output Queue: Conversation 72
Bandwidth 16 (kbps) Packets Matched 0
(pkts discards/bytes discards) 0/0
Class immediate-data
Weighted Fair Queueing
Output Queue: Conversation 73
Bandwidth 60 (%) Packets Matched 0
(pkts discards/bytes discards/tail drops) 0/0/0
mean queue depth: 0
drops: class random tail min-th max-th mark-prob
0 0 0 64 128 1/10
1 0 0 71 128 1/10
2 0 0 78 128 1/10
3 0 0 85 128 1/10
4 0 0 92 128 1/10
5 0 0 99 128 1/10
6 0 0 106 128 1/10
7 0 0 113 128 1/10
rsvp 0 0 120 128 1/10
Class priority-data
Weighted Fair Queueing
Output Queue: Conversation 74
Bandwidth 40 (%) Packets Matched 0 Max Threshold 64 (packets)
(pkts discards/bytes discards/tail drops) 0/0/0
Class class-default
Weighted Fair Queueing
Flow Based Fair Queueing
Maximum Number of Hashed Queues 64 Max Threshold 20 (packets)
Output queue size 0/max total 600/drops 0
fragment type end-to-end fragment size 50
cir 64000 bc 640 be 0 limit 80 interval 10
mincir 64000 byte increment 80 BECN response no
frags 0 bytes 0 frags delayed 0 bytes delayed 0
shaping inactive
traffic shaping drops 0
The following is sample output from the show frame-relay pvc command that shows the PVC statistics for serial interface 5 (slot 1 and DLCI 55 are up) during a PPP session over Frame Relay:
Router# show frame-relay pvc 55
PVC Statistics for interface Serial5/1 (Frame Relay DTE)
DLCI = 55, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial5/1.1
input pkts 9 output pkts 16 in bytes 154
out bytes 338 dropped pkts 6 in FECN pkts 0
in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
in DE pkts 0 out DE pkts 0
out bcast pkts 0 out bcast bytes 0
pvc create time 00:35:11, last time pvc status changed 00:00:22
Bound to Virtual-Access1 (up, cloned from Virtual-Template5)
The following is sample output from the show frame-relay pvc command for a PVC carrying Voice over Frame Relay (VoFR) traffic configured via the vofr cisco command. The frame-relay voice bandwidth command has been configured on the class associated with this PVC, as has fragmentation. The fragmentation employed is proprietary to Cisco.
A sample configuration for this scenario is shown first, followed by the output for the show frame-relay pvc command.
interface serial 0
encapsulation frame-relay
frame-relay traffic-shaping
frame-relay interface-dlci 108
vofr cisco
class vofr-class
map-class frame-relay vofr-class
frame-relay fragment 100
frame-relay fair-queue
frame-relay cir 64000
frame-relay voice bandwidth 25000
Router# show frame-relay pvc 108
PVC Statistics for interface Serial0 (Frame Relay DTE)
DLCI = 108, DLCI USAGE = LOCAL, PVC STATUS = STATIC, INTERFACE = Serial0
input pkts 1260 output pkts 1271 in bytes 95671
out bytes 98604 dropped pkts 0 in FECN pkts 0
in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
in DE pkts 0 out DE pkts 0
out bcast pkts 1271 out bcast bytes 98604
pvc create time 09:43:17, last time pvc status changed 09:43:17
Service type VoFR-cisco
configured voice bandwidth 25000, used voice bandwidth 0
voice reserved queues 24, 25
fragment type VoFR-cisco fragment size 100
cir 64000 bc 64000 be 0 limit 1000 interval 125
mincir 32000 byte increment 1000 BECN response no
pkts 2592 bytes 205140 pkts delayed 1296 bytes delayed 102570
shaping inactive
shaping drops 0
Current fair queue configuration:
Discard Dynamic Reserved
threshold queue count queue count
64 16 2
Output queue size 0/max total 600/drops 0
Note that the "fragment type" field in the show frame-relay pvc command display can have the following entries:
The following is sample output from the show frame-relay pvc command for an application employing pure FRF.12 fragmentation. A sample configuration for this scenario is shown first, followed by the output for the show frame-relay pvc command.
interface serial 0
encapsulation frame-relay
frame-relay traffic-shaping
frame-relay interface-dlci 110
class frag
map-class frame-relay frag
frame-relay fragment 100
frame-relay fair-queue
frame-relay cir 64000
Router# show frame-relay pvc 110
PVC Statistics for interface Serial0 (Frame Relay DTE)
DLCI = 110, DLCI USAGE = LOCAL, PVC STATUS = STATIC, INTERFACE = Serial0
input pkts 0 output pkts 243 in bytes 0
out bytes 7290 dropped pkts 0 in FECN pkts 0
in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
in DE pkts 0 out DE pkts 0
out bcast pkts 243 out bcast bytes 7290
pvc create time 04:03:17, last time pvc status changed 04:03:18
fragment type end-to-end fragment size 100
cir 64000 bc 64000 be 0 limit 1000 interval 125
mincir 32000 byte increment 1000 BECN response no
pkts 486 bytes 14580 pkts delayed 243 bytes delayed 7290
shaping inactive
shaping drops 0
Current fair queue configuration:
Discard Dynamic Reserved
threshold queue count queue count
64 16 2
Output queue size 0/max total 600/drops 0
Note that when voice is not configured, voice bandwidth output is not displayed.
The following is sample output from the show frame-relay pvc command for multipoint subinterfaces carrying data only. The output displays both the subinterface number and the DLCI. This display is the same whether the PVC is configured for static or dynamic addressing. Note that neither fragmentation nor voice is configured on this PVC.
Router# show frame-relay pvc DLCI = 300, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0.103 input pkts 10 output pkts 7 in bytes 6222 out bytes 6034 dropped pkts 0 in FECN pkts 0 in BECN pkts 0 out FECN pkts 0 out BECN pkts 0 in DE pkts 0 out DE pkts 0 outbcast pkts 0 outbcast bytes 0 pvc create time 0:13:11 last time pvc status changed 0:11:46 DLCI = 400, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0.104 input pkts 20 output pkts 8 in bytes 5624 out bytes 5222 dropped pkts 0 in FECN pkts 0 in BECN pkts 0 out FECN pkts 0 out BECN pkts 0 in DE pkts 0 out DE pkts 0 outbcast pkts 0 outbcast bytes 0 pvc create time 0:03:57 last time pvc status changed 0:03:48
The following is sample output from the show frame-relay pvc command for a PVC carrying voice and data traffic, with a special queue specifically for voice traffic created using the frame-relay voice bandwidth command queue keyword:
Router# show frame-relay pvc interface serial 1 45
PVC Statistics for interface Serial1 (Frame Relay DTE)
DLCI = 45, DLCI USAGE = LOCAL, PVC STATUS = STATIC, INTERFACE = Serial1
input pkts 85 output pkts 289 in bytes 1730
out bytes 6580 dropped pkts 11 in FECN pkts 0
in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
in DE pkts 0 out DE pkts 0
out bcast pkts 0 out bcast bytes 0
pvc create time 00:02:09, last time pvc status changed 00:02:09
Service type VoFR
configured voice bandwidth 25000, used voice bandwidth 22000
fragment type VoFR fragment size 100
cir 20000 bc 1000 be 0 limit 125 interval 50
mincir 20000 byte increment 125 BECN response no
fragments 290 bytes 6613 fragments delayed 1 bytes delayed 33
shaping inactive
traffic shaping drops 0
Voice Queueing Stats: 0/100/0 (size/max/dropped)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Current fair queue configuration:
Discard Dynamic Reserved
threshold queue count queue count
64 16 2
Output queue size 0/max total 600/drops 0
Table 1 provides a listing of the fields in these displays and a description of each field.
| Field | Description |
|---|---|
DLCI | One of the DLCI numbers for the PVC. |
DLCI USAGE | Lists SWITCHED when the router or access server is used as a switch, or LOCAL when the router or access server is used as a DTE device. |
PVC STATUS | Status of the PVC: ACTIVE, INACTIVE, or DELETED. |
INTERFACE | Specific subinterface associated with this DLCI. |
input pkts | Number of packets received on this PVC. |
output pkts | Number of packets sent on this PVC. |
in bytes | Number of bytes received on this PVC. |
out bytes | Number of bytes sent on this PVC. |
dropped pkts | Number of incoming and outgoing packets dropped by the router at the Frame Relay level. |
in FECN pkts | Number of packets received with the FECN bit set. |
in BECN pkts | Number of packets received with the BECN bit set. |
out FECN pkts | Number of packets sent with the FECN bit set. |
out BECN pkts | Number of packets sent with the BECN bit set. |
in DE pkts | Number of DE packets received. |
out DE pkts | Number of DE packets sent. |
out bcast pkts | Number of output broadcast packets. |
out bcast bytes | Number of output broadcast bytes. |
pvc create time | Time at which the PVC was created. |
last time pvc status changed | Time at which the PVC changed status (active to inactive). |
priority | Priority assigned to the PVC. |
Service type | Type of service performed by this PVC. Can be VoFR or VoFR-cisco. |
configured voice bandwidth | Amount of bandwidth in bits per second (bps) reserved for voice traffic on this PVC. |
used voice bandwidth | Amount of bandwidth in bps currently being used for voice traffic. |
voice reserved queues | Queue numbers reserved for voice traffic on this PVC. This field was removed in Cisco IOS Release 12.0(5)T. |
service policy | Name of the output service policy applied to the VC. |
Class | Class of traffic being displayed. Output is displayed for each configured class in the policy. |
Output Queue | The WFQ conversation to which this class of traffic is allocated. |
Bandwidth | Bandwidth in kbps or percentage configured for this class. |
Packets Matched | Number of packets that matched this class. |
Max Threshold | Maximum queue size for this class when WRED is not used. |
pkts discards | Number of packets discarded for this class. |
bytes discards | Number of bytes discarded for this class. |
tail drops | Number of packets discarded for this class because the queue was full. |
mean queue depth | Average queue depth based on the actual queue depth on the interface and the exponential weighting constant. It is a moving average. The minimum and maximum thresholds are compared against this value to determine drop decisions. |
drops: | WRED parameters. |
| IP Precedence value. |
| Number of packets randomly dropped when the mean queue depth is between the minimum threshold value and the maximum threshold value for the specified IP Precedence value. |
| Number of packets dropped when the mean queue depth is greater than the maximum threshold value for the specified IP Precedence value. |
| Minimum WRED threshold in number of packets. |
| Maximum WRED threshold in number of packets. |
| Fraction of packets dropped when the average queue depth is at the maximum threshold. |
Maximum Number of Hashed Queues | (Applies to class default only) Number of queues available for unclassified flows. |
fragment type | Type of fragmentation configured for this PVC. Possible types are: end-to-end---Fragmented packets contain the standard FRF.12 header VoFR---Fragmented packets contain the FRF.11 Annex C header VoFR-cisco---Fragmented packets contain the Cisco proprietary header |
fragment size | Size of the fragment payload in bytes. |
cir | Current CIR in bps. |
bc | Current Committed Burst (Bc) size in bits. |
be | Current Excess Burst (Be) size in bits. |
limit | Maximum number of bytes sent per internal interval (excess plus sustained). |
interval | Interval being used internally (may be smaller than the interval derived from Bc/CIR; this happens when the router determines that traffic flow will be more stable with a smaller configured interval). |
mincir | Minimum CIR for the PVC. |
byte increment | Number of bytes that will be sustained per internal interval. |
BECN response | Indication that Frame Relay has BECN Adaptation configured. |
pkts | Number of packets associated with this PVC that have gone through the traffic shaping system. |
frags | Total number of fragments shaped on this VC. |
bytes | Number of bytes associated with this PVC that have gone through the traffic shaping system. |
pkts delayed | Number of packets associated with this PVC that have been delayed by the traffic shaping system. |
frags delayed | Number of fragments delayed in the shaping queue before being sent. |
bytes delayed | Number of bytes associated with this PVC that have been delayed by the traffic shaping system. |
shaping | Indication that shaping will be active for all PVCs that are fragmenting data; otherwise, shaping will be active if the traffic being sent exceeds the CIR for this circuit. |
shaping drops | Number of packets dropped by the traffic shaping process. |
Voice Queueing Stats | Statistics showing the size of packets, the maximum number of packets, and the number of packets dropped in the special voice queue created using the frame-relay voice bandwidth command queue keyword. |
Discard threshold | Maximum number of packets that can be stored in each packet queue. Additional packets received after a queue is full will be discarded. |
Dynamic queue count | Number of packet queues reserved for best-effort traffic. |
Reserved queue count | Number of packet queues reserved for voice traffic. |
Output queue size | Size in bytes of each output queue. |
max total | Maximum number of packets of all types that can be queued in all queues. |
drops | Number of frames dropped by all output queues. |
Related Commands
frame-relay interface-queue priority Enables FR PIPQ on a Frame Relay interface, and assigns priority to a PVC within a Frame Relay map class. frame-relay pvc Configures Frame Relay PVCs for FRF.8 Frame Relay-ATM Service Interworking. service-policy Attaches a policy map to an input interface or VC, or an output interface or VC, to be used as the service policy for that interface or VC. show dial-peer voice Displays configuration information and call statistics for dial peers. show frame-relay fragment Displays Frame Relay fragmentation details. show frame-relay vofr Displays details about FRF.11 subchannels being used on VoFR DLCIs. show interfaces serial Displays information about a serial interface. show policy-map interface Displays the configuration of classes configured for service policies on the specified interface or PVC. show traffic-shape queue Displays information about the elements queued at a particular time at the VC (DLCI) level.
Command
Description
To display statistics for all interfaces configured on the router or access server, use the show interfaces privileged EXEC command. The resulting output varies, depending on the network for which an interface has been configured.
show interfaces [type number] [first] [last] [accounting] Cisco7200 Series and Cisco7500 Series with a Packet over SONET Interface Processor
show interfaces [type slot/port] [accounting]
Cisco7500 Series with Ports on VIPs
show interfaces [type slot/port-adapter/port] [ethernet | serial]
Syntax Description
type (Optional) Interface type. Allowed values for the type argument are async, bri0, dialer, ethernet, fastethernet, fddi, hssi, loopback, null, serial, tokenring, and tunnel. For the Cisco4000 series routers, the type argument can be e1, ethernet, fastethernet, fddi, serial, t1, and token. For the Cisco4500 series routers, the type argument can also include atm. For the Cisco7000 family, the type argument can be atm, e1, ethernet, fastethernet, fddi, serial, t1, and tokenring. For the Cisco7500 series, the type argument can also include pos. number (Optional) Port number on the selected interface. first last (Optional) For Cisco2500 and 3000 series routers, ISDN BRI only. The first argument can be either 1 or 2. The last argument can only be 2, indicating Bchannels 1 and 2. D-channel information is obtained by using the command without the optional arguments. accounting (Optional) Displays the number of packets of each protocol type that have been sent through the interface. slot (Optional) Number of the slot being configured. Refer to the appropriate hardware manual for slot and port information. port (Optional) Number of the port being configured. Refer to the appropriate hardware manual for slot and port information. port-adapter (Optional) Number of the port adapter being configured. Refer to the appropriate hardware manual for information about port adapter compatibility.
Command Modes
Privileged EXEC
Command History
10.0 This command was introduced. 12.0(3)T This command was modified to include support for flow-based Weighted Random Early Detection (WRED). 12.0(4)T This command was modified to include enhanced display information for dialer bound interfaces. 12.0(7)T This command was modified to include the dialer keyword as an interface type, and to reflect the default behavior. 12.1(2)T This command was modified to display information about the priority queues within the Frame Relay PVC Interface Priority Queueing (FR PIPQ) feature.
Release
Modification
Usage Guidelines
The show interfaces command displays statistics for the network interfaces. The resulting display on the Cisco7200 series routers shows the interface processors in slot order. If you add interface processors after booting the system, they will appear at the end of the list, in the order in which they were inserted.
If you use the show interfaces command on the Cisco7200 series routers without the slot/port arguments, information for all interface types will be shown. For example, if you enter the show interfaces ethernet command, you will receive information for all Ethernet, serial, Token Ring, and FDDI interfaces. Only by adding the type slot/port argument can you specify a particular interface.
If you enter a show interfaces command for an interface type that has been removed from the router or access server, interface statistics will be displayed accompanied by the following text: "Hardware has been removed."
If you use the show interfaces command on a router or access server for which interfaces are configured to use weighted fair queueing (WFQ) through the fair-queue interface configuration command, additional information is displayed. This information consists of the current and high-water mark number of flows.
If you use the show interfaces command on dialer interfaces configured for binding, the display will report statistics on each physical interface bound to the dialer interface; see the examples in the following section for more information.
You will use the show interfaces command frequently while configuring and monitoring devices. The various forms of the show interfaces commands are shown in detail in the "Examples" section of this command.
Examples
The following is sample output from the show interfaces command. Because your display will depend on the type and number of interface cards in your router or access server, only a portion of the display is shown.
Router# show interfaces Ethernet 0 is up, line protocol is up Hardware is MCI Ethernet, address is 0000.0c00.750c (bia 0000.0c00.750c) Internet address is 131.108.28.8, subnet mask is 255.255.255.0 MTU 1500 bytes, BW 10000 Kbit, DLY 100000 usec, rely 255/255, load 1/255 Encapsulation ARPA, loopback not set, keepalive set (10 sec) ARP type: ARPA, ARP Timeout 4:00:00 Last input 0:00:00, output 0:00:00, output hang never Last clearing of "show interface" counters 0:00:00 Output queue 0/40, 0 drops; input queue 0/75, 0 drops Five minute input rate 0 bits/sec, 0 packets/sec
Five minute output rate 2000 bits/sec, 4 packets/sec
1127576 packets input, 447251251 bytes, 0 no buffer
Received 354125 broadcasts, 0 runts, 0 giants
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
5332142 packets output, 496316039 bytes, 0 underruns
0 output errors, 432 collisions, 0 interface resets, 0 restarts
.
.
.
Frame Relay PVC Interface Priority Queueing Example
The following is sample output from the show interfaces command when FR PIPQ is enabled on serial interface 0:
Router# show interfaces Serial0
Serial3/2 is up, line protocol is up
Hardware is M4T
MTU 1500 bytes, BW 2048 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation FRAME-RELAY, crc 16, loopback not set
Keepalive set (10 sec)
LMI enq sent 7, LMI stat recvd 7, LMI upd recvd 0, DTE LMI up
LMI enq recvd 0, LMI stat sent 0, LMI upd sent 0
LMI DLCI 0 LMI type is ANSI Annex D frame relay DTE
FR SVC disabled, LAPF state down
Broadcast queue 0/64, broadcasts sent/dropped 0/0, interface broadcasts 0
Last input 00:00:08, output 00:00:08, output hang never
Last clearing of "show interface" counters 00:01:31
Input queue:0/75/0 (size/max/drops); Total output drops:0
Queueing strategy:DLCI priority
Output queue (queue priority:size/max/drops):
high:0/20/0, medium:0/40/0, normal:0/60/0, low:0/80/0
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
7 packets input, 173 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
7 packets output, 98 bytes, 0 underruns
0 output errors, 0 collisions, 2 interface resets
0 output buffer failures, 0 output buffers swapped out
2 carrier transitions DCD=up DSR=up DTR=up RTS=up CTS=up
Table 2 shows the output fields relevant to FR PIPQ.
| Field | Description |
|---|---|
Queueing strategy | Queueing strategy configured on the interface. Displays "DLCI priority" when FR PIPQ is enabled. |
Output queue | Queue for which statistics will be displayed. |
queue priority: | Priority queue for which statistics will be displayed. |
| Number of packets currently in the queue. |
| Maximum number of packets the queue will hold before it begins dropping packets. |
| Number of packets dropped. |
Custom Output Queueing Example
The following is partial sample output when custom output queueing is enabled:
Last clearing of "show interface" counters 0:00:06
Input queue: 0/75/0 (size/max/drops); Total output drops: 21
Output queues: (queue #: size/max/drops)
0: 14/20/14 1: 0/20/6 2: 0/20/0 3: 0/20/0 4: 0/20/0 5: 0/20/0
6: 0/20/0 7: 0/20/0 8: 0/20/0 9: 0/20/0 10: 0/20/0
When custom queueing is enabled, the drops accounted for in the output queues result from bandwidth limitation for the associated traffic and lead to queue length overflow. Total output drops include drops on all custom queues and the system queue. Fields are described with the weighted fair queueing (WFQ) output in Table 3.
WFQ Output Example
In the following sample output, each interface on the router or access server configured to use WFQ, the show interfaces command displays the information beginning with the "Input queue:" line:
Router# show interfaces
Ethernet 0 is up, line protocol is up
Hardware is MCI Ethernet, address is 0000.0c00.750c (bia 0000.0c00.750c)
Internet address is 131.108.28.8, subnet mask is 255.255.255.0
MTU 1500 bytes, BW 10000 Kbit, DLY 100000 usec, rely 255/255, load 1/255
Encapsulation ARPA, loopback not set, keepalive set (10 sec)
ARP type: ARPA, ARP Timeout 4:00:00
Last input 0:00:00, output 0:00:00, output hang never
Last clearing of "show interface" counters 0:00:00
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
Five minute input rate 0 bits/sec, 0 packets/sec
Five minute output rate 2000 bits/sec, 4 packets/sec
1127576 packets input, 447251251 bytes, 0 no buffer
Received 354125 broadcasts, 0 runts, 0 giants
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
5332142 packets output, 496316039 bytes, 0 underruns
0 output errors, 432 collisions, 0 interface resets, 0 restarts
Input queue: 0/75/0 (size/max/drops); Total output drops: 0
Output queue: 7/64/0 (size/threshold/drops)
Conversations 2/9 (active/max active)
Table 3 provides a listing of input queue and output queue fields shown in the preceding display.
| Field | Description |
|---|---|
Input queue |
|
| Current size of the input queue. |
| Maximum size of the queue. |
| Number of messages discarded in this interval. |
| Total number of messages discarded in this session. |
Output queue |
|
| Current size of the output queue. |
| Congestive-discard threshold. Number of messages in the queue after which new messages for high-bandwidth conversations are dropped. |
| Number of dropped messages. |
| Number of currently active conversations. |
| Maximum number of concurrent conversations allowed. |
accounting Option Example
To display the number of packets of each protocol type that have been sent through all configured interfaces, use the show interfaces accounting keyword EXEC command. When you use the accounting option, only the accounting statistics are displayed.
|
NoteExcept for protocols that are encapsulated inside other protocols, such as IP over X.25, the accounting option also shows the total of all bytes sent and received, including the MAC header. For example, it totals the size of the Ethernet packet or the size of a packet that includes High-Level Data Link Control (HDLC) encapsulation. |
Per-packet accounting information is kept for the following protocols:
The following is sample output from the show interfaces command when Distributed Weighted Random Early Detection (DWRED) is enabled on an interface. Notice that the packet drop strategy is listed as "VIP-based weighted RED."
Router# show interfaces hssi0/0/0 Hssi0/0/0 is up, line protocol is up Hardware is cyBus HSSI Description: 45Mbps to R1 Internet address is 200.200.14.250/30 MTU 4470 bytes, BW 45045 Kbit, DLY 200 usec, rely 255/255, load 1/255 Encapsulation HDLC, loopback not set, keepalive set (10 sec) Last input 00:00:02, output 00:00:03, output hang never Last clearing of "show interface" counters never Queueing strategy: fifo Packet Drop strategy: VIP-based weighted RED Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 1976 packets input, 131263 bytes, 0 no buffer Received 1577 broadcasts, 0 runts, 0 giants 0 parity 4 input errors, 4 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 1939 packets output, 130910 bytes, 0 underruns 0 output errors, 0 applique, 3 interface resets 0 output buffers copied, 0 interrupts, 0 failures
ALC Example
The following is sample output from the show interfaces command for the serial 2 interface when ALC is enabled:
Router# show interfaces serial 2 Serial2 is up, line protocol is up Hardware is CD2430 MTU 1500 bytes, BW 115 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation ALC, loopback not set Full-duplex enabled. ascus in UP state: 42, 46 ascus in DOWN state: ascus DISABLED: Last input never, output never, output hang never Last clearing of "show interface" counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 0 packets input, 0 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 0 packets output, 0 bytes, 0 underruns 0 output errors, 0 collisions, 3 interface resets 0 output buffer failures, 0 output buffers swapped out DCD=down DSR=down DTR=down RTS=down CTS=down
SDLC Example
The following is sample output from the show interfaces command for an SDLC primary interface supporting the SDLC function:
Router# show interfaces
Serial 0 is up, line protocol is up
Hardware is MCI Serial
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255
Encapsulation SDLC-PRIMARY, loopback not set
Timers (msec): poll pause 100 fair poll 500. Poll limit 1
[T1 3000, N1 12016, N2 20, K 7] timer: 56608 Last polled device: none
SDLLC [ma: 0000.0C01.14--, ring: 7 bridge: 1, target ring: 10
largest token ring frame 2052]
SDLC addr C1 state is CONNECT
VS 6, VR 3, RCNT 0, Remote VR 6, Current retransmit count 0
Hold queue: 0/12 IFRAMEs 77/22 RNRs 0/0 SNRMs 1/0 DISCs 0/0
Poll: clear, Poll count: 0, chain: p: C1 n: C1
SDLLC [largest SDLC frame: 265, XID: disabled]
Last input 00:00:02, output 00:00:01, output hang never
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
Five minute input rate 517 bits/sec, 30 packets/sec
Five minute output rate 672 bits/sec, 20 packets/sec
357 packets input, 28382 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
926 packets output, 77274 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets, 0 restarts
2 carrier transitions
Table 4 shows the fields relevant to all SDLC connections.
| Field | Description |
|---|---|
Timers (msec) | List of timers in milliseconds. |
poll pause, fair poll, Poll limit | Current values of these timers, as described in the individual commands in this chapter. |
T1, N1, N2, K | Current values for these variables, as described in the individual commands in this chapter. |
Table 5 shows other data given for each SDLC secondary configured to be attached to this interface.
| Field | Description |
|---|---|
addr | Address of this secondary. |
state | Current state of this connection. The possible values are:
|
VS | Sequence number of the next information frame this station sends. |
VR | Sequence number of the next information frame from this secondary that this station expects to receive. |
RCNT | Number of correctly sequenced I-frames received when the CiscoIOS software was in a state in which it is acceptable to receive I-frames. |
Remote VR | Last frame sent by this station was acknowledged by the other station. |
Current retransmit count | Number of times the current I-frame or sequence of I-frames was re-sent. |
Hold queue | Number of frames in the hold queue/maximum size of hold queue. |
IFRAMEs, RNRs, SNRMs, DISCs | Sent/received count for these frames. |
Poll | "Set" if this router has a poll outstanding to the secondary; "clear" if it does not. |
Poll count | Number of polls, in a row, given to this secondary at this time. |
chain | Indicates the previous (p) and next (n) secondary address on this interface in the round-robin loop of polled devices. |
show interfaces accounting Example
The following is sample output from the show interfaces accounting command:
Router# show interfaces accounting
Interface TokenRing0 is disabled
Ethernet0
Protocol Pkts In Chars In Pkts Out Chars Out
IP 873171 735923409 34624 9644258
Novell 163849 12361626 57143 4272468
DEC MOP 0 0 1 77
ARP 69618 4177080 1529 91740
Interface Serial0 is disabled
Ethernet1
Protocol Pkts In Chars In Pkts Out Chars Out
IP 0 0 37 11845
Novell 0 0 4591 275460
DEC MOP 0 0 1 77
ARP 0 0 7 420
Interface Serial1 is disabled
Interface Ethernet2 is disabled
Interface Serial2 is disabled
Interface Ethernet3 is disabled
Interface Serial3 is disabled
Interface Ethernet4 is disabled
Interface Ethernet5 is disabled
Interface Ethernet6 is disabled
Interface Ethernet7 is disabled
Interface Ethernet8 is disabled
Interface Ethernet9 is disabled
Fddi0
Protocol Pkts In Chars In Pkts Out Chars Out
Novell 0 0 183 11163
ARP 1 49 0 0
When the output indicates an interface is "disabled," the router has received an excessive number of errors (over 5000 in a keepalive period).
Flow-Based WRED Example
The following is sample output from the show interfaces command issued for the serial1 interface for which flow-based WRED is enabled. The output shows 8 active flow-based WRED flows, that the maximum number of flows active at any time is 9, and that the maximum number of possible flows configured for the interface is 16.
Router# show interfaces serial1 Serial1 is up, line protocol is up Hardware is HD64570 Internet address is 190.1.2.1/24 MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, Reliability 255/255, txload 237/255, rxload 1/255 Encapsulation HDLC, loopback not set Keepalive not set Last input 00:00:22, output 00:00:00, output hang never Last clearing of "show interface" counters 00:17:58 Input queue: 0/75/0 (size/max/drops); Total output drops: 2479
Queueing strategy: random early detection(RED)
flows (active/max active/max): 8/9/16
mean queue depth: 27
drops: class random tail min-th max-th mark-prob
0 946 0 20 40 1/10
1 488 0 22 40 1/10
2 429 0 24 40 1/10
3 341 0 26 40 1/10
4 235 0 28 40 1/10
5 40 0 31 40 1/10
6 0 0 33 40 1/10
7 0 0 35 40 1/10
rsvp 0 0 37 40 1/10
30 second input rate 1000 bits/sec, 2 packets/sec
30 second output rate 119000 bits/sec, 126 packets/sec
1346 packets input, 83808 bytes, 0 no buffer
Received 12 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
84543 packets output, 9977642 bytes, 0 underruns
0 output errors, 0 collisions, 6 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up
DWFQ Example
The following is sample output from the show interfaces command when distributed weighted fair queueing (DWFQ) is enabled on an interface. Notice that the queueing strategy is listed as "VIP-based fair queueing."
Router# show interfaces fastethernet 1/1/0
Fast Ethernet 1/1/0 is up, line protocol is up
Hardware is cyBus Fast Ethernet Interface, address is 0007.f618.4448 (bia 00e0)
Description: pkt input i/f for WRL tests (to pagent)
Internet address is 80.0.2.70/24
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, rely 255/255, load 1/255
Encapsulation ARPA, loopback not set, keepalive not set, fdx, 100BaseTX/FX
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output 01:11:01, output hang never
Last clearing of "show interface" counters 01:12:31
Queueing strategy: VIP-based fair queueing
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
30 second input rate 0 bits/sec, 0 packets/sec
30 second output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
0 watchdog, 0 multicast
0 input packets with dribble condition detected
1 packets output, 60 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffers copied, 0 interrupts, 0 failures
DNIS Binding Example
The following is sample output when the show interfaces command is used on an unbound dialer interface:
Router# show interfaces dialer0
Dialer0 is up (spoofing), line protocol is up (spoofing) Hardware is Unknown Internet address is 21.1.1.2/8 MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec, rely 255/255, load 3/255 Encapsulation PPP, loopback not set DTR is pulsed for 1 seconds on reset Last input 00:00:34, output never, output hang never Last clearing of "show interface" counters 00:05:09 Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 1000 bits/sec, 0 packets/sec 18 packets input, 2579 bytes 14 packets output, 5328 bytes
When the show interfaces command is issued on a bound dialer interface, you will get an additional report indicating the binding relationship. The output looks as follows:
Router# show interfaces dialer0
Dialer0 is up, line protocol is up Hardware is Unknown Internet address is 21.1.1.2/8 MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation PPP, loopback not set DTR is pulsed for 1 seconds on reset Interface is bound to BRI0:1 Last input 00:00:38, output never, output hang never Last clearing of "show interface" counters 00:05:36
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
38 packets input, 4659 bytes
34 packets output, 9952 bytes
Bound to:
BRI0:1 is up, line protocol is up
Hardware is BRI
MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec, rely 255/255, load 1/255
Encapsulation PPP, loopback not set, keepalive not set
Interface is bound to Dialer0 (Encapsulation PPP)
LCP Open, multilink Open
Last input 00:00:39, output 00:00:11, output hang never
Last clearing of "show interface" counters never
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
78 packets input, 9317 bytes, 0 no buffer
Received 65 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
93 packets output, 9864 bytes, 0 underruns
0 output errors, 0 collisions, 7 interface resets
0 output buffer failures, 0 output buffers swapped out
4 carrier transitions
At the end of dialer0 output, the show interfaces command is executed on each physical interface bound to it.
In the following sample output, the physical interface is the B1 channel of the bri0 link. This example also illustrates that the output under the B channel keeps all hardware counts that are not displayed under any logical or virtual access interface. The line in the report that states "Interface is bound to Dialer0 (Encapsulation LAPB)" indicates that this B interface is bound to Dialer0 and the encapsulation running over this connection is Link Access Procedure, Balanced (LAPB), not PPP, which is the encapsulation configured on the D interface and inherited by the B channel.
Router# show interfaces bri0:1
BRI0:1 is up, line protocol is up Hardware is BRI MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation PPP, loopback not set, keepalive not setInterface is bound to Dialer0 (Encapsulation LAPB)LCP Open, multilink Open Last input 00:00:31, output 00:00:03, output hang never Last clearing of "show interface" counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 1 packets/sec 5 minute output rate 0 bits/sec, 1 packets/sec 110 packets input, 13994 bytes, 0 no buffer Received 91 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 135 packets output, 14175 bytes, 0 underruns 0 output errors, 0 collisions, 12 interface resets 0 output buffer failures, 0 output buffers swapped out 8 carrier transitions
Any protocol configuration and states should be displayed from the Dialer0 interface.
Syntax Description
(Optional) Status of the custom queueing list configuration. (Optional) Status of the fair queueing configuration. (Optional) Status of the priority queueing list configuration. (Optional) Status of the weighted random early detection (WRED) and distributed weighted random early detection (DWRED) configuration, including configuration of flow-based WRED. interface atm_subinterface (Optional) Displays the WRED parameters of every virtual circuit (VC) with WRED enabled on the specified ATM subinterface. vc (Optional) Displays the WRED parameters associated with a specific VC. If desired, both the virtual path identifier (VPI) and virtual circuit identifier (VCI) values, or just the VCI value, can be specified. vpi/ (Optional) Specifies the VPI. If the vpi argument is omitted, 0 is used as the VPI value for locating the permanent virtual circuit (PVC). If the vpi argument is specified, the / separator is required. vci (Optional) Specifies the VCI.
Defaults
If no keyword is entered, this command shows the configuration of all interfaces.
Command Modes
Privileged EXEC
Command History
10.3 This command was introduced. 12.0(4)T The red keyword was changed to random-detect. 12.1(2)T This command was modified to include information about the Frame Relay PVC Interface Priority Queueing (FR PIPQ) feature.
Release
Modification
Examples
FR PIPQ Example
The following sample output shows that FR PIPQ (referred to as "DLCI priority queue") is configured on serial interface 0. The output also shows the size of the four DLCI priority queues.
Router# show queueing
Current fair queue configuration:
Interface Discard Dynamic Reserved
threshold queue count queue count
Serial3/1 64 256 0
Serial3/3 64 256 0
Current DLCI priority queue configuration:
Interface High Medium Normal Low
limit limit limit limit
Serial0 20 40 60 80
Current priority queue configuration:
List Queue Args
1 low protocol ipx
1 normal protocol vines
1 normal protocol appletalk
1 normal protocol ip
1 normal protocol decnet
1 normal protocol decnet_node
1 normal protocol decnet_rout
1 normal protocol decnet_rout
1 medium protocol xns
1 high protocol clns
1 normal protocol bridge
1 normal protocol arp
Current custom queue configuration:
Current random-detect configuration:
Weighted Fair Queueing Example
The following is sample output from the show queueing command. Two active conversations are in serial interface 0. Weighted fair queueing (WFQ) ensures that both of these IP data streams---both using TCP---receive equal bandwidth on the interface while they have messages in the pipeline, even though more FTP data is in the queue than remote copy protocol (RCP) data.
Router# show queueing
Current fair queue configuration:
Interface Discard Dynamic Reserved
threshold queue count queue count
Serial0 64 256 0
Serial1 64 256 0
Serial2 64 256 0
Serial3 64 256 0
Current priority queue configuration:
List Queue Args
1 high protocol cdp
2 medium interface Ethernet1
Current custom queue configuration:
Current random-detect configuration:
Serial5
Queueing strategy:random early detection (WRED)
Exp-weight-constant:9 (1/512)
Mean queue depth:40
Class Random Tail Minimum Maximum Mark
drop drop threshold threshold probability
0 1401906620401/10
1 0 022401/10
2 0 024401/10
3 0 026401/10
4 0 028401/10
5 0 031401/10
6 0 033401/10
7 0 035401/10
rsvp0037401/10
Custom Queueing Example
The following is sample output from the show queueing custom command:
Router# show queueing custom Current custom queue configuration: List Queue Args 3 10 default 3 3 interface Tunnel3 3 3 protocol ip 3 3 byte-count 444 limit 3
Flow-Based WRED Example
The following is sample output from the show queueing random-detect command. The output shows that the interface is configured for flow-based WRED to ensure fair packet drop among flows. The random-detect flow average-depth-factor command was used to configure a scaling factor of 8 for this interface. The scaling factor is used to scale the number of buffers available per flow and to determine the number of packets allowed in the output queue of each active flow before the queue is susceptible to packet drop. The maximum flow count for this interface was set to 16 by the random-detect flow count command.
Router# show queueing random-detect
Current random-detect configuration:
Serial1
Queueing strategy:random early detection (WRED)
Exp-weight-constant:9 (1/512)
Mean queue depth:29
Max flow count:16 Average depth factor:8
Flows (active/max active/max):39/40/16
Class Random Tail Minimum Maximum Mark
drop drop threshold threshold probability
0 31 0 20 40 1/10
1 33 0 22 40 1/10
2 18 0 24 40 1/10
3 14 0 26 40 1/10
4 10 0 28 40 1/10
5 0 0 31 40 1/10
6 0 0 33 40 1/10
7 0 0 35 40 1/10
rsvp 0 0 37 40 1/10
DWRED Example
The following is sample output from the show queueing random-detect command for DWRED:
Current random-detect configuration:
FastEthernet2/0/0
Queueing strategy:fifo
Packet drop strategy:VIP-based random early detection (DWRED)
Exp-weight-constant:9 (1/512)
Mean queue depth:0
Queue size:0 Maximum available buffers:6308
Output packets:5 WRED drops:0 No buffer:0
Class Random Tail Minimum Maximum Mark Output
drop drop threshold threshold probability Packets
0 0 0 1092181/10 5
1 0 0 1222181/10 0
2 0 0 1352181/10 0
3 0 0 1482181/10 0
4 0 0 1612181/10 0
5 0 0 1742181/10 0
6 0 0 1872181/10 0
7 0 0 2002181/10 0
Table 6 describes the fields shown in the preceding displays.
| Field | Description |
|---|---|
Discard threshold | Number of messages allowed in each queue. |
Dynamic queue count | Number of dynamic queues used for best-effort conversations. |
Reserved queue count | Number of reservable queues used for reserved conversations. |
High limit | High DLCI priority queue size in maximum number of packets. |
Medium limit | Medium DLCI priority queue size in maximum number of packets. |
Normal limit | Normal DLCI priority queue size in maximum number of packets. |
Low limit | Low DLCI priority queue size in maximum number of packets. |
List | Custom queueing---Number of the queue list. Priority queueing---Number of the priority list. |
Queue | Custom queueing---Number of the queue. Priority queueing---Priority queue level (high, medium, normal, or low). |
Args | Packet matching criteria for that queue. |
Exp-weight-constant | Exponential weight factor. |
Mean queue depth | Average queue depth. It is calculated based on the actual queue depth on the interface and the exponential weighting constant. It is a moving average. The minimum and maximum thresholds are compared against this value to determine drop decisions. |
Class | IP Precedence value. |
Random drop | Number of packets randomly dropped when the mean queue depth is between the minimum threshold value and the maximum threshold value for the specified IP Precedence value. |
Tail drop | Number of packets dropped when the mean queue depth is greater than the maximum threshold value for the specified IP Precedence value. |
Minimum threshold | Minimum WRED threshold in number of packets. |
Maximum threshold | Maximum WRED threshold in number of packets. |
Mark probability | Fraction of packets dropped when the average queue depth is at the maximum threshold. |
Related Commands
custom-queue-list Assigns a custom queue list to an interface. fair-queue (WFQ) Enables WFQ for an interface. frame-relay interface-queue priority Enables FR PIPQ on a Frame Relay interface, and assigns priority to a PVC within a Frame Relay map class. exponential-weighting-constant Configures the exponential weight factor for the average queue size calculation for a WRED parameter group. precedence Configures a WRED group for a particular IP Precedence. priority-group Assigns the specified priority list to an interface. priority-list interface Establishes queueing priorities on packets entering from a given interface. priority-list queue-limit Specifies the maximum number of packets that can be waiting in each of the priority queues. queue-list interface Establishes queueing priorities on packets entering on an interface. queue-list queue byte-count Specifies how many bytes the system allows to be delivered from a given queue during a particular cycle. random-detect (interface) Enables WRED or DWRED. random-detect flow average-depth-factor Sets the multiplier to be used in determining the average depth factor for a flow when flow-based WRED is enabled. random-detect flow count Sets the flow count for flow-based WRED. show interfaces Displays the statistical information specific to a serial interface. show queue Displays the contents of packets inside a queue for a particular interface or VC. show queueing interface Displays the queueing statistics of an interface or VC.
Command
Description
This section documents the modified debug priority command. All other commands used with this feature are documented in the Cisco IOS Release 12.1 command reference publications.
To debug priority output queueing, use the debug priority privileged EXEC command. To disable debugging output, use the no form of this command.
debug prioritySyntax Description
This command has no arguments or keywords.
Defaults
No default behavior or values.
Command Modes
Privileged EXEC
Command History
12.1(2)T This command was modified to include information about PVC priority.
Release
Modification
Examples
The following example shows how to debug priority output queueing:
Router# debug priority Priority output queueing debugging is on Router#
The following is sample output from the debug priority command when the Frame Relay PVC Interface Priority Queueing (FR PIPQ) feature is configured on serial interface 0:
Router# debug priority 00:49:05:PQ:Serial0 dlci 100 -> high 00:49:05:PQ:Serial0 output (Pk size/Q 24/0) 00:49:05:PQ:Serial0 dlci 100 -> high 00:49:05:PQ:Serial0 output (Pk size/Q 24/0) 00:49:05:PQ:Serial0 dlci 100 -> high 00:49:05:PQ:Serial0 output (Pk size/Q 24/0) 00:49:05:PQ:Serial0 dlci 200 -> medium 00:49:05:PQ:Serial0 output (Pk size/Q 24/1) 00:49:05:PQ:Serial0 dlci 300 -> normal 00:49:05:PQ:Serial0 output (Pk size/Q 24/2) 00:49:05:PQ:Serial0 dlci 400 -> low 00:49:05:PQ:Serial0 output (Pk size/Q 24/3)
DLCI---data-link connection identifier. Value that specifies a permanent virtual circuit (PVC) or switched virtual circuit (SVC) in a Frame Relay network.
FIFO queueing--- First-in, first-out queueing. FIFO involves buffering and forwarding of packets in the order of arrival. FIFO embodies no concept of priority or classes of traffic. There is only one queue, and all packets are treated equally. Packets are sent out an interface in the order in which they arrive.
Frame Relay traffic shaping---See FRTS.
FRF.12---The FRF.12 Implementation Agreement was developed to allow long data frames to be fragmented into smaller pieces and interleaved with real-time frames. In this way, real-time voice and nonreal-time data frames can be carried together on lower-speed links without causing excessive delay to the real-time traffic.
FRTS---Frame Relay traffic shaping. FRTS uses queues on a Frame Relay network to limit surges that can cause congestion. Data is buffered and then sent into the network in regulated amounts to ensure that the traffic will fit within the promised traffic envelope for the particular connection.
PIPQ---Permanent virtual circuit (PVC) interface priority queueing. An interface-level priority queueing scheme in which prioritization is based on destination PVC rather than packet contents.
quality of service---Measure of performance for a transmission system that reflects its transmission quality and service availability.
VoFR---Voice over Frame Relay. Enables a router to carry voice traffic over a Frame Relay network. When voice traffic is sent over Frame Relay, the voice traffic is segmented and encapsulated for transit across the Frame Relay network using FRF.12 encapsulation.
Voice over Frame Relay---See VoFR.
WFQ---weighted fair queueing. Congestion management algorithm that identifies conversations (in the form of traffic streams), separates packets that belong to each conversation, and ensures that capacity is shared fairly among these individual conversations. WFQ is an automatic way of stabilizing network behavior during congestion and results in increased performance and reduced retransmission.
WRED---Weighted Random Early Detection. Combines IP Precedence and standard Random Early Detection (RED) to allow for preferential handling of voice traffic under congestion conditions without exacerbating the congestion. WRED uses and interprets IP Precedence to give priority to voice traffic over data traffic, dropping only data packets.
Posted: Fri May 19 09:06:29 PDT 2000
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