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The MultiNode Load Balancing (MNLB) forwarding agent is the IOS-based packet redirector component of the MNLD Feature Set for LocalDirector, a product in the Cisco family of load balancing solutions.
The forwarding agent discovers the destination of specific connection requests and forwards packets between the client and the chosen destination. When a forwarding agent receives a connection request, the request is forwarded to the MNLB services manager, the LocalDirector-based component of the MNLD Feature Set for LocalDirector. The services manager makes the load balancing decision and sends the forwarding agent the optimal destination. After the destination is specified, session data is forwarded directly to the destination by the forwarding agent, without further services manager participation. There is no limit to the number of forwarding agents that can be configured in the MNLD Feature Set for LocalDirector.
The MNLD Feature Set for LocalDirector comprises hardware and software that runs on multiple network components. The services manager runs on Cisco's LocalDirector chassis and makes the load-balancing decisions. The forwarding agents run on Cisco IOS router and switch platforms and forward packets to and from the selected destination. Separating the decision-making and packet-forwarding tasks enables much faster packet throughput. The underlying Cisco architecture, ContentFlow architecture, enables high availability, unbounded scalability, application-aware balancing, no single point of failure, and unmatched performance.
Configure the forwarding agent only if you are installing the MNLD Feature Set for LocalDirector. If you are installing the MNLD Feature Set for LocalDirector, refer to the MultiNode Load Balancing Feature Set for LocalDirector User Guide for information about which other hardware and software components are required.
The MNLB forwarding agent is an implementation of Cisco's ContentFlow architecture flow delivery agent (FDA).
Refer to the MultiNode Load Balancing Feature Set for LocalDirector User Guide for more information about how the forwarding agent is configured and for more information about the product.
This feature is supported on these platforms:
This feature supports the following MIB:
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.
No RFCs are supported by this feature.
The following sections describe forwarding agent configuration tasks:
Cisco Express Forwarding (CEF) is advanced Layer 3 IP switching technology. CEF optimizes network performance and scalability for networks with large and dynamic traffic patterns, such as the Internet, on networks characterized by intensive Web-based applications, or interactive sessions.
To enable CEF, use the following command in global configuration mode:
| Command | Purpose |
|---|---|
Router(config) ip cef distributed | Enables CEF. |
| Step | Command | Purpose | ||
|---|---|---|---|---|
| Router(config-if)# ip flow-cache feature-accelerate | Specifies IP flow cache. | ||
| Router(config-if)# interface type slot/port-adapter/port Router(config-if)# interface type slot/port (Cisco 7200 series routers | Specifies the interface, and enters interface configuration mode. | ||
| Router(config-if)# ip route-cache flow | Enables flow switching on the interface. |
Normally the size of the NetFlow cache will meet your needs. However, you can increase or decrease the number of entries maintained in the cache by using the following command in global configuration mode
| Command | Purpose |
|---|---|
Router(config)# ip flow-cache entries number | Changes the number of entries maintained in the NetFlow cache. The number of entries can be 1024 to 524288. The default is 64536. |
You must enable multicast routing on all interfaces to the services manager.
To enable multicast routing on all interfaces, use the following command in global configuration mode:
| Command | Purpose |
|---|---|
Router(config)# ip multicast routing | Enables multicast routing. |
To have the router join a multicast group and enable IGMP, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Router(config-if)# ip igmp join-group1 group-address2 | Joins a multicast group. |
| 1This command must be configured on all interfaces that will listen for the services manager multicasts. 2The group address must match that configured within the services manager configuration. |
To configure the router as a forwarding agent, use the following commands, beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| Router(config)# ip casa control-address igmp-address | Specify the control address and IGMP address of the forwarding agent. The control address is a unique ip address used by forwarding-agent to send and receive control message between the service manager and the forwarding-agent. The recommended IGMP address is 224.0.1.2. | ||
| Router(config-casa)# forwarding-agent pool initial_affinity_pool max_affinity_pool | Adjusts the memory allocated for the forwarding agent's affinity pools. The default pool size is 5000 and there is no maximum pool size. | ||
| Router(config-casa)# forwarding-agent num [passwd [timeout]] | Specifies the port number. |
To monitor the status of the forwarding agent, use the following commands in EXEC mode:
| Command | Purpose |
|---|---|
Router# show ip casa affinities | Displays the status of affinities. |
Router# show ip casa oper | Displays the operational status of the forwarding agent. |
Router# show ip casa stats | Displays statistical information about the forwarding agent. |
Router# show ip casa wildcard | Displays information about wildcard blocks. |
This section provides the following configuration examples:
The network configured is shown in Figure 1.
The following is a sample, of a router configured as a forwarding agent. In this example all disabled interfaces have been omitted to simplify the display.
FA2#wr t Building configuration... Current configuration: ! version 12.0 service timestamps debug uptime service timestamps log uptime no service password-encryption service udp-small-servers service tcp-small-servers ! hostname FA2 ! ! microcode CIP flash slot0:cip26-5 microcode reload ip subnet-zero ip flow-cache feature-accelerate no ip domain-lookup ! ip cef distributed ip casa 206.10.20.34 224.0.1.2 forwarding-agent 1637 ! interface Ethernet0/0 ip address 172.26.56.18 255.255.255.224 no ip directed-broadcast ip route-cache flow ip igmp join-group 224.0.1.2 no ip mroute-cache ! interface Ethernet0/1 ip address 172.26.56.37 255.255.255.224 no ip directed-broadcast ! ! ! router eigrp 777 network 172.26.0.0 ! no ip classless ! line con 0 exec-timeout 0 0 transport input none line aux 0 line vty 0 4 exec-timeout 0 0 login ! end
SM# wr t Building configuration... : Saved : LocalDirector 420 Version 3.0.0.127 syslog output 20.3 no syslog console enable password 000000000000000000000000000000 encrypted hostname SM no shutdown ethernet 0 no shutdown ethernet 1 no shutdown ethernet 2 no shutdown ethernet 3 interface ethernet 0 auto interface ethernet 1 auto interface ethernet 2 auto interface ethernet 3 auto mtu 0 1500 mtu 1 1500 mtu 2 1500 mtu 3 1500 multiring all no secure 0 no secure 1 no secure 2 no secure 3 ping-allow 0 ping-allow 1 ping-allow 2 ping-allow 3 ip address 172.26.56.19 255.255.255.248 route 172.26.10.249 255.255.255.255 172.26.56.20 1 route 206.10.20.33 255.255.255.255 172.26.56.17 1 route 206.10.20.34 255.255.255.255 172.26.56.18 1 no rip passive failover ip address 0.0.0.0 failover password cisco telnet 161.0.0.0 255.0.0.0 no snmp-server contact no snmp-server location casa service-manager port 1638 casa service-manager multicast-ttl 60 tftp-server 172.26.10.249 /tftpboot/LD virtual 172.26.56.13:0:0:tcp is virtual 172.26.56.2:0:0:tcp is redirection 172.26.56.13:0:0:tcp dispatched casa wildcard-ttl 60 fixed-ttl 60 igmp 224.0.1.2 port 1637 redirection 172.26.56.2:0:0:tcp dispatched casa wildcard-ttl 60 fixed-ttl 60 igmp 224.0.1.2 port 1637 real 172.26.56.34:0:0:tcp is real 172.26.56.33:0:0:tcp is real 172.26.56.6:0:0:tcp is real 172.26.56.10:0:0:tcp is bind 172.26.56.13:0:0:tcp 172.26.56.33:0:0:tcp bind 172.26.56.13:0:0:tcp 172.26.56.34:0:0:tcp bind 172.26.56.2:0:0:tcp 172.26.56.10:0:0:tcp bind 172.26.56.2:0:0:tcp 172.26.56.6:0:0:tcp : end
This section documents new commands. All other commands used with this feature are documented in the Cisco IOS Release 12.0 command reference publication.
In Cisco IOS Release 12.0(1)T or later, you can search and filter the output for show and more commands. This functionality is useful when you need to sort through large amounts of output, or if you want to exclude output that you do not need to see.
To use this functionality, enter a show or more command followed by the "pipe" character (|), one of the keywords begin, include, or exclude, and an expression that you want to search or filter on:
command | {begin | include | exclude} regular-expression
Following is an example of the show atm vc command in which you want the command output to begin with the first line where the expression "PeakRate" appears:
show atm vc | begin PeakRate
For more information on the search and filter functionality, refer to the Cisco IOS Release 12.0(1)T feature module titled CLI String Search.
To specify the port on which the forwarding agent will listen for wildcard and fixed affinities, use the forwarding-agent CASA-port configuration command. Use the no form of the command to disable listening on that port.
forwarding-agent num [password [timeout]]
num | Port numbers on which the forwarding agent will listen for wildcards broadcast from the services manager. This must match the port number defined on the services manager. |
password | (Optional) Text password used for generating the MD5 digest. |
timeout | (Optional) Duration in seconds during which the forwarding agent will accept the new and old password. Valid range is between 0 and 3600 seconds. The default is 180 seconds. |
The default password timeout is 180 seconds.
The default port for the services manager is 1637.
CASA-port configuration
| Release | Modification |
|---|---|
12.0(5)T | This command was introduced. |
The following example specifies that the forwarding agent will listen for wildcard and fixed affinities on port 1637:
forwarding-agent 1637
| Command | Description |
show ip casa oper | Displays operational information about the forwarding agent. |
To to adjust the memory allocated for the forwarding agent's affinity pools, use the forwarding-agent pool CASA-port configuration command. Use the no form of the command to restore the default memory allocation.
forwarding-agent pool initial_affinity_pool max_affinity_pool
initial_affinity_pool | Initial number of memory blocks allocated for use as affinities. The default is 5000. |
max_affinity_pool | Maximum number of memory blocks that can be allocated for use as affinities. The default is no maximum. |
The default initial affinity pool size is 5000 memory blocks. There is no maximum.
CASA-port configuration
| Release | Modification |
|---|---|
12.0(5)T | This command was introduced. |
The following example specifies a configuration of 100,000 initial affinity memory block that can increase to a maximum of 1,000,000 entries:
forwarding-agent pool 100000 1000000
| Command | Description |
show ip casa oper | Displays operational information about the forwarding agent. |
To configure the router to function as an MNLB forwarding agent, use the ip casa global configuration command. Use the no form of the command to disable the forwarding agent.
ip casa control-address igmp-addr
control-address | IP address of the forwarding agent side of the services manager/forwarding agent tunnel used for sending signals. This address is unique for each forwarding agent. |
igmp-addr | IGMP address on which the forwarding agent will listen for wildcard and fixed affinities. |
No default behavior or values.
Global configuration
| Release | Modification |
|---|---|
12.0(5)T | This command was introduced. |
The following example specifies the internet address (10.10.4.1) and IGMP address (224.0.1.2) for the forwarding agent:
ip-casa 10.10.4.1 224.0.1.2
| Command | Description |
forwarding-agent | Specifies the port on which the forwarding agent will listen for wildcard and fixed affinities. |
To display statistics about affinities, use the show ip casa affinities EXEC command.
show ip casa affinities [stats] | [saddr ipaddr [detail]] | [daddr ipaddr [detail]] | sport sport [detail]] | dport dport [detail]] | protocol protocol [detail]]
stats | (Optional) Displays limited statistics. |
saddr ipaddr | (Optional) Displays source address of a given TCP connection. |
daddr ipaddr | (Optional) Displays destination address of a given TCP connection. |
sport sport | (Optional) Displays source port of a given TCP connection. |
dport dport | (Optional) Displays destination port of a given TCP connection. |
protocol protocol | (Optional) Displays protocol of a given TCP connection. |
detail | (Optional) Displays detailed statistics. |
EXEC
| Release | Modification |
|---|---|
12.0(5)T | This command was introduced. |
The following is sample output of the show ip casa affinities command:
Router# show ip casa affinities Affinity Table Source Address Port Dest Address Port Prot 161.44.36.118 1118 172.26.56.13 19 TCP 172.26.56.13 19 161.44.36.118 1118 TCP
The following is sample output of the show ip casa affinities detail command
Router# show ip casa affinities detail Affinity Table Source Address Port Dest Address Port Prot 161.44.36.118 1118 172.26.56.13 19 TCP Action Details: Interest Addr: 172.26.56.19 Interest Port: 1638 Interest Packet: 0x0102 SYN FRAG Interest Tickle: 0x0005 FIN RST Dispatch (Layer 2): YES Dispatch Address: 172.26.56.33 Source Address Port Dest Address Port Prot 172.26.56.13 19 161.44.36.118 1118 TCP Action Details: Interest Addr: 172.26.56.19 Interest Port: 1638 Interest Packet: 0x0104 RST FRAG Interest Tickle: 0x0003 FIN SYN Dispatch (Layer 2): NO Dispatch Address: 0.0.0.0
Table 1 describes significant fields shown in the display.
| Command | Description |
forwarding-agent | Specifies the port number on which the forwarding agent will listen for wildcards and fixed affinities. |
show ip casa oper | Shows operational information about the forwarding agent. |
To display operational information about the forwarding agent, use the show ip casa oper EXEC command.
show ip casa operThis command has no arguments or keywords.
EXEC
| Release | Modification |
|---|---|
12.0(5)T | This command was introduced. |
The following is sample output of the show ip casa oper command:
Router# show ip casa oper Casa is Active Casa control address is 206.10.20.34/32 Casa multicast address is 224.0.1.2 Listening for wildcards on: Port:1637 Current passwd:NONE Pending passwd:NONE Passwd timeout:180 sec (Default)
Table 2 describes significant fields shown in the display.
| Field | Description |
|---|---|
Casa is Active | The forwarding agent is active. |
Casa control address | Unique address for this forwarding agent. |
Casa multicast address | Services manager broadcast address. |
Listening for wildcards on | Port on which the forwarding agent will listen. |
Port | Services manager broadcast port. |
Current passwd | Current password. |
Pending passwd | Password that will override the current password. |
Passwd timeout | Interval after which the pending password becomes the current password. |
| Command | Description |
ip casa | Configures the router to function as an MNLB forwarding agent. |
To display statistical information about the forwarding agent, use the show ip casa stats EXEC command.
show ip casa statsThis command has no arguments or keywords.
EXEC
| Release | Modification |
|---|---|
12.0(5)T | This command was introduced. |
The following is sample output of the show ip casa stats command:
Router# show ip casa stats
Casa is active:
Wildcard Stats:
Wildcards: 6 Max Wildcards: 6
Wildcard Denies: 0 Wildcard Drops: 0
Pkts Throughput: 441 Bytes Throughput: 39120
Affinity Stats:
Affinities: 2 Max Affinities: 2
Cache Hits: 444 Cache Misses: 0
Affinity Drops: 0
Casa Stats:
Int Packet: 4 Int Tickle: 0
Casa Denies: 0 Drop Count: 0
Table 3 describes significant fields shown in the display.
| Field | Description |
|---|---|
Casa is Active | The forwarding agent is active. |
Wildcard Stats | Wildcard statistics. |
Wildcards | Number of current wildcards. |
Max Wildcards | Maximum number of wildcards since the forwarding agent became active. |
Wildcard Denies | Protocol violations. |
Wildcard Drops | No memory to install wildcard. |
Pkts Throughput | Number of packets passed through all wildcards. |
Bytes Throughput | Number of bytes passed through all wildcards. |
Affinity Stats | Affinity statistics. |
Affinities | Current number of affinities. |
Max Affinities | Maximum number of affinities since the forwarding agent became active. |
Cache Hits | Number of packets that match wildcards and fixed affinities. |
Cache Misses | Matched wildcard, missed fix. |
Affinity Drops | Number of times an affinity could not be created. |
Casa Stats | Forwarding agent statistics. |
Int Packet | Interest packets. |
Int Tickle | Interest tickles. |
Casa Denies | Protocol violation. |
Security Drops | Packets dropped due to password or authentication mismatch. |
Drop Count | Number of messages dropped. |
| Command | Description |
show ip casa oper | Shows operational information about the forwarding agent. |
To display information about wildcard blocks, use the show ip casa wildcard EXEC command.
show ip casa wildcard [detail]
detail | (Optional) Displays detailed statistics. |
EXEC
| Release | Modification |
|---|---|
12.0(5)T | This command was introduced. |
The following is sample output of the show ip casa wildcard command:
Router# show ip casa wildcard Source Address Source Mask Port Dest Address Dest Mask Port Prot 0.0.0.0 0.0.0.0 0 172.26.56.2 255.255.255.255 0 ICMP 0.0.0.0 0.0.0.0 0 172.26.56.2 255.255.255.255 0 TCP 0.0.0.0 0.0.0.0 0 172.26.56.13 255.255.255.255 0 ICMP 0.0.0.0 0.0.0.0 0 172.26.56.13 255.255.255.255 0 TCP 172.26.56.2 255.255.255.255 0 0.0.0.0 0.0.0.0 0 TCP 172.26.56.13 255.255.255.255 0 0.0.0.0 0.0.0.0 0 TCP
The following is sample output of the show ip casa wildcard detail command:
router# show ip casa wild detail
Source Address Source Mask Port Dest Address Dest Mask Port Prot
0.0.0.0 0.0.0.0 0 172.26.56.2 255.255.255.255 0 ICMP
Service Manager Details:
Manager Addr: 172.26.56.19 Insert Time: 08:21:27 UTC 04/18/96
Affinity Statistics:
Affinity Count: 0 Interest Packet Timeouts: 0
Packet Statistics:
Packets: 0 Bytes: 0
Action Details:
Interest Addr: 172.26.56.19 Interest Port: 1638
Interest Packet: 0x8000 ALLPKTS
Interest Tickle: 0x0107 FIN SYN RST FRAG
Dispatch (Layer 2): NO Dispatch Address: 0.0.0.0
Advertise Dest Address: YES Match Fragments: NO
Source Address Source Mask Port Dest Address Dest Mask Port Prot
0.0.0.0 0.0.0.0 0 172.26.56.2 255.255.255.255 0 TCP
Service Manager Details:
Manager Addr: 172.26.56.19 Insert Time: 08:21:27 UTC 04/18/96
Affinity Statistics:
Affinity Count: 0 Interest Packet Timeouts: 0
Packet Statistics:
Packets: 0 Bytes: 0
Action Details:
Interest Addr: 172.26.56.19 Interest Port: 1638
Interest Packet: 0x8102 SYN FRAG ALLPKTS
Interest Tickle: 0x0005 FIN RST
Dispatch (Layer 2): NO Dispatch Address: 0.0.0.0
Advertise Dest Address: YES Match Fragments: NO
Table 4 describes significant fields shown in the display.
| Field | Description |
|---|---|
Source Address | Source address of a given TCP connection. |
Source Mask | Mask to apply to source address before matching. |
Port | Source port of a given TCP connection. |
Dest Address | Destination address of a given TCP connection. |
Dest Mask | Mask to apply to destination address before matching. |
Port | Destination port of a given TCP connection. |
Prot | Protocol of a given TCP connection. |
Service Manager Details | Services manager details. |
Manager Addr | Source address of this wildcard. |
Insert Time | System time at which this wildcard was inserted. |
Affinity Statistics | Affinity statistics. |
Affinity Count | Number of affinities created on behalf of this wildcard. |
Interest Packet Timeouts | Number of unanswered interest packets. |
Packet Statistics | Packet statistics. |
Packets | Number of packets that match this wildcard. |
Bytes | Number of bytes that match this wildcard. |
Action Details | Actions to be taken on a match. |
Interest Addr | Services manager that is to receive interest packets for this wildcard. |
Interest Port | Services manager port to which interest packets are sent. |
Interest Packet | List of packet types that the services manager is interested in. |
Interest Tickle | List of packet types for which the services manager wants the entire packet. |
Dispatch (Layer 2) | Layer 2 destination information will be modified. |
Dispatch Address | Address of the real server. |
Advertise Dest Address | Destination address. |
Match Fragments | Does wildcard also match fragments? (boolean) |
| Command | Description |
show ip casa oper | Shows operational information about the forwarding agent. |
To display debug messages for affinities, use the debug ip casa affinities privileged EXEC command. Use the no form of the command to disable debugging.
[no] debug ip casa affinitiesThis command has no arguments or keywords.
Debugging for affinities is not enabled.
| Release | Modification |
|---|---|
12.0(5)T | This command was introduced. |
The following is output from the debug ip casa affinities command:
Router# debug ip casa affinities 16:15:36:Adding fixed affinity: 16:15:36: 10.10.1.1:54787 -> 10.10.10.10:23 proto = 6 16:15:36:Updating fixed affinity: 16:15:36: 10.10.1.1:54787 -> 10.10.10.10:23 proto = 6 16:15:36: flags = 0x2, appl addr = 10.10.3.2, interest = 0x5/0x100 16:15:36: int ip:port = 10.10.2.2:1638, sequence delta = 0/0/0/0 16:15:36:Adding fixed affinity: 16:15:36: 10.10.10.10:23 -> 10.10.1.1:54787 proto = 6 16:15:36:Updating fixed affinity: 16:15:36: 10.10.10.10:23 -> 10.10.1.1:54787 proto = 6 16:15:36: flags = 0x2, appl addr = 0.0.0.0, interest = 0x3/0x104 16:15:36: int ip:port = 10.10.2.2:1638, sequence delta = 0/0/0/0
Table 5 describes significant fields of the debug output.
| Field | Description |
|---|---|
Adding fixed affinity | Adding a fixed affinity to affinity table. |
Updating fixed affinity | Modifying a fixed affinity table with information from the services manager. |
flags | Bit field indicating actions to be taken on this affinity. |
fwd addr | Address to which packets will be directed. |
interest | Services manager that's interested in packets for this affinity. |
int ip:port | Services manager port to which interest packets are sent. |
sequence delta | Used to adjust TCP sequence numbers for this affinity. |
To display debug messages for packets, use the debug ip casa packets privileged EXEC command. Use the no form of the command to disable debugging.
[no] debug ip casa packetsThis command has no arguments or keywords.
Debugging for packets is not enabled.
| Release | Modification |
|---|---|
12.0(5)T | This command was introduced. |
The following is output from the debug ip casa packets command:
Router# debug ip casa packets 16:15:36:Routing CASA packet - TO_MGR: 16:15:36: 10.10.1.1:55299 -> 10.10.10.10:23 proto = 6 16:15:36: Interest Addr:10.10.2.2 Port:1638 16:15:36:Routing CASA packet - FWD_PKT: 16:15:36: 10.10.1.1:55299 -> 10.10.10.10:23 proto = 6 16:15:36: Fwd Addr:10.10.3.2 16:15:36:Routing CASA packet - TO_MGR: 16:15:36: 10.10.10.10:23 -> 10.10.1.1:55299 proto = 6 16:15:36: Interest Addr:10.10.2.2 Port:1638 16:15:36:Routing CASA packet - FWD_PKT: 16:15:36: 10.10.10.10:23 -> 10.10.1.1:55299 proto = 6 16:15:36: Fwd Addr:0.0.0.0 16:15:36:Routing CASA packet - TICKLE: 16:15:36: 10.10.10.10:23 -> 10.10.1.1:55299 proto = 6 16:15:36: Interest Addr:10.10.2.2 Port:1638 Interest Mask:SYN 16:15:36: Fwd Addr:0.0.0.0 16:15:36:Routing CASA packet - FWD_PKT: 16:15:36: 10.10.1.1:55299 -> 10.10.10.10:23 proto = 6 16:15:36: Fwd Addr:10.10.3.2
Table 6 describes significant fields in the debug output.
| Field | Description |
|---|---|
Routing CASA packet - TO_MGR | Forwarding agent is routing a packet to the services manager. |
Routing CASA packet - FWD_PKT | Forwarding agent is routing a packet to the forwarding address. |
Routing CASA packet - TICKLE | Forwarding agent is signalling services manager while allowing the packet in question to take the appropriate action. |
Interest Addr | Services manager address. |
Interest Port | Port on the services manager where packet is sent. |
Fwd Addr | Address to which packets matching the affinity are sent. |
Interest Mask | Services manager that is interested in packets for this affinity. |
To display debug messages for wildcards, use the debug ip casa wildcards privileged EXEC command. Use the no form of this command to disable debugging.
[no] debug ip casa wildcardsThis command has no arguments or keywords.
Debugging for wildcards is not enabled.
| Release | Modification |
|---|---|
12.0(5)T | This command was introduced. |
The following is output from the debug ip casa wildcards command:
Router# debug ip casa wildcards 16:13:23:Updating wildcard affinity: 16:13:23: 10.10.10.10:0 -> 0.0.0.0:0 proto = 6 16:13:23: src mask = 255.255.255.255, dest mask = 0.0.0.0 16:13:23: no frag, not advertising 16:13:23: flags = 0x0, appl addr = 0.0.0.0, interest = 0x8107/0x8104 16:13:23: int ip:port = 10.10.2.2:1638, sequence delta = 0/0/0/0 16:13:23:Updating wildcard affinity: 16:13:23: 0.0.0.0:0 -> 10.10.10.10:0 proto = 6 16:13:23: src mask = 0.0.0.0, dest mask = 255.255.255.255 16:13:23: no frag, advertising 16:13:23: flags = 0x0, appl addr = 0.0.0.0, interest = 0x8107/0x8102 16:13:23 int ip:port = 10.10.2.2:1638, sequence delta = 0/0/0/0
Table 7describes significant fields in the debug output.
| Field | Description |
|---|---|
src mask | Source of connection. |
dest mask | Destination of connection. |
no frag, not advertising | Not accepting IP fragments. |
flags | Bit field indicating actions to be taken on this affinity. |
fwd addr | Address to which packets matching the affinity will be directed. |
interest | Services manager that's interested in packets for this affinity. |
int ip: port | Services manager port to which interest packets are sent. |
sequence delta | Used to adjust sequence numbers for this affinity. |
affinity---The set of information that uniquely describes the association of a client to a particular host within a server cluster. It relates the addresses found in the IP packet (protocol, client IP address, port, local port, cluster address) to the IP address of the local host that has been assigned to handle all packets with that unique set of addresses.
CEF---Cisco Express Forwarding.
cluster---A set of computer systems that are connected together through multisystem hardware or software to provide services traditionally provided by a single system. This arrangement provides higher availability and better scalability.
cluster address---The IP address that represents the entire cluster of hosts. It is defined in each server and each forwarding agent router. The routers advertise routes to their internal instances of this address. The servers do not advertise the address, but recognize it as one of their local, or loopback addresses.
ContentFlow architecture---A Cisco protocol that enables communication between a services manager and a forwarding agent.
control address---An IP address assigned to the IP cluster function within each router. It is unique to each router and is used for management flows.
forwarding agent---MultiNode Load Balancing forwarding agent. Fulfills routing decisions made by the services manager. The forwarding agent filters packets coming into the virtual network and sends to the services manager packets that are without a known server destination.
load balancing---Spreading user requests among available servers within a cluster of servers, based on a variety of algorithms.
LocalDirector---Cisco LocalDirector is hardware and software that provide one of the platforms for the MNLB services manager.
MD5--- Message Digest Algorithm Version 5, a neighbor router authentication scheme used to ensure reliability and security when routing updates are to be exchanged between neighbor routers.
NetFlow switching---High-performance network-layer switching path that captures as part of its switching function a rich set of traffic statistics including user, protocol, port, and type of service information.
services manager---MultiNode Load Balancing services manager. Using load balancing and server/application feedback, the services manager determines a real server for the packet flow. Once the optimal destination is decided, all other packets in the packet flow are directed to a forwarding agent and real server, increasing packet throughput. In the MNLD Feature Set for LocalDirector, the services manager function is performed by the LocalDirector.
server farm---Also called a server cluster, a group of real servers that provide various applications and services.
tag switching---Packet-forwarding strategy that maps Layer 3 header contents into a fixed-length, unstructured value called a tag. In effect, a tag represents a forwarding equivalence class; that is, a set of packets that, however different they may be, are indistinguishable to the forwarding function. The tag does not represent a particular path through the network. In general the path continues to be chosen by the existing Layer 3 routing algorithms.
virtual server---Presents a single address that represents an application server farm for clients.
Posted: Tue Apr 18 12:33:41 PDT 2000
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