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This chapter describes commands such as filtering and address learning used to configure transparent bridging.
To delete one or all of the manually entered Ethernet addresses stored in the filtering table with the set address command, use the reset address command.
REset ADdress address | ALl
address | Deletes an Ethernet address that has been previously entered with the set address command. Must be entered as 12 contiguous hexadecimal characters (no spaces). |
ALl | Deletes all Ethernet addresses in the profile that have been entered with the set address command. |
Profile mode
The following example deletes one static address from the profile 2503:
Host:2503> reset address 00000c00755d
set address
To delete one or all user-defined bridge filters, use the reset filter command.
REset [id] FIlter = [ALl]
id | Deletes filters based on the identification number assigned to the filter when it is created with the set filter command. |
ALl | Deletes all filters. |
None
System or profile mode
The following example deletes the filter with the identification number 4 from profile 2503:
Host:2503> reset 4 filter
The following example deletes all filters from profile 2503:
Host:2503> reset filter all
set filter
show filter
To delete one or all bridge filtering patterns, use the reset pattern command.
REset [patternname] PATtern = [ALl]
patternname | Deletes a specific pattern based on the pattern name assigned with the set pattern command. |
PATtern ALl | Deletes all patterns. |
None
System mode
The following example deletes a pattern called arp from profile 2503:
Host:2503> reset arp pattern
The following example deletes all patterns from profile 2503:
Host:2503> reset pattern all
set pattern
show pattern
To delete one or all bridge type filters, use the reset type command.
REset TYpe = type | ALl
type | Deletes a type filter based on the packet type defined with the set type command. Must be in the form of a four-digit hexadecimal number with no spaces. |
ALl | Deletes all types of filters. |
None
System mode
The following example deletes a type filter based on packet type:
Host> reset type 0806
The following example deletes all type filters:
Host> reset type all
set type
To add an Ethernet address to a profile's static address table, use the set address command. This command applies only to bridging.
SEt ADdress = address
address | Adds the specified Ethernet address to the profile's static address table. Must be entered as 12 contiguous hexadecimal characters (no spaces). The Ethernet address cannot exist on the same network as the router. Static addresses are associated with the profile's connection. Packets received from the LAN or ISDN line that contains a static address as a destination address will be forwarded to the connection of the profile containing that static address. |
No static addresses are configured.
Profile mode
To delete an address entered with this command, use the reset address command. The Cisco Remote Office (RO) version routers can store up to 1500 Ethernet addresses in a combination of learned and static addresses. The Cisco Small Office Home Office (SOHO) version routers can store only four Ethernet addresses.
The following example adds a static Ethernet address to the profile 2503:
Host:2503> set address 00000c1235ff
reset address
seconds | The time in seconds that any inactive learned Ethernet address remains in the address table. Must be between 1 and 1,000,000. When the router receives a packet with a source address matching a learned address, the age for that address is reset to 0. |
OFf | Learned Ethernet addresses remain in the address table indefinitely. |
Off
System mode
The following example configures the router to delete learned Ethernet addresses after one hour of no activity from the address:
Host> set age 60
To determine what to do with packets that cannot be routed, use the set bridging command.
SEt BRidging ON | OFfON | Packet will be bridged based on Media Access Control (MAC) address and any other filters currently active. |
OFf | Drop packets. |
On
System mode
The following example drops packets that cannot be routed:
Host> set bridging off
To create a user-defined bridge filter, use the set filter command.
SEt [id] FIlter [patternname] [BLock | ACcept] [DEmand | IGnore]
id | The filter ID argument is assigned by the router and is not used to create a filter. It is used to modify existing filter configurations. |
patternname | A pattern created with the set pattern command. Filters are composed of patterns. This argument can have up to eight pattern names. If you are using more than one pattern in a filter, all patterns must use the same (from) value in the set pattern command. |
BLock | Prevents packets that match the filter from being forwarded to the connection. |
ACcept | Allows only packets that match the filter to be forwarded to the connection. |
DEmand | Packets that match the filter are counted in the threshold values that keep the ISDN line connected. |
IGnore | Packets that match the filter are not counted in the threshold values that keep the ISDN line connected. |
No filters are configured.
System or profile mode
Although multiple filters can be defined as accept, block, demand or ignore, the most recently defined filter determines which set of filters is used. When the packet comes in, it is evaluated by the most recent filter. If that filter blocks the packet, the packet is dropped, even if another filter would have accepted the packet.
Filters defined in system mode are used by all profiles. Filters defined in profile mode are used by that profile only. Filters apply to packets received from the connection associated with the profile in which the filters are defined.
To display filter IDs, use the show filter command.
The following example configures a filter that will be used by all profiles:
Host> set filter arp demand
reset filter
set filter
set ip filter
show filter
show ip filter
set pattern
To enable or disable the Ethernet address learning function, use the set learn command.
SEt LEarn ON | OFf
ON | Enables Ethernet address learning. Addresses are associated with a profile connection and are used for making bridge filtering decisions. |
OFf | Disables Ethernet address learning. Only addresses entered with the set address command are used to make packet forwarding decisions. |
On (Enabled)
Profile mode
This command applies only when bridging is enabled with the set bridging command.
The following example enables Ethernet address learning on the profile 2503 connection:
Host:2503> set learn on
set address
set bridging
set mode
To configure packet forwarding for bridging, use the set mode command.
SEt [WAN | LAN] MOde = ANy | ONly
WAN | Applies the configuration to packets received from the LAN and destined for the ISDN line. |
LAN | Applies the configuration to packets received from the ISDN line and destined for the LAN. |
ANy | Packets with unknown destination addresses are forwarded to all active connections. |
ONly | Packets with unknown destination addresses are discarded. |
wan only
lan any
System mode
Addresses are learned either by enabling learning with the set learn command or by entering them manually with the set address command.
The following example configures the router to forward any packets with unknown destination addresses from the LAN to the ISDN line:
Host> set wan mode any
set address
set learn
To configure packet bridging between ISDN connections, use the set passthru command.
SEt PASSThru ON | OFf
ON | Enables individual remote routers to bridge to each other through the router. |
OFf | Remote routers can only bridge to devices on the same LAN as the router. |
Off (Disabled)
System mode
The following example enables individual remote routers to bridge to each other through the router:
Host> set passthru on
To create a pattern for user-defined bridge filters or IP generic filters, use the set pattern command.
SEt patternname [PAttern = hexpattern binarypattern decimalpattern [OFfset = number] [FRom=BEGINNING | TYPEFIELD | IPHDR | TCPHDR | UDPHDR | TCPDATA | UDPDATA] PATTERNName = patternname]
patternname | Name of the pattern. Can consist of 1 to 7 characters. |
PAttern | Value of the pattern. Must be between 1 and 6 bytes, separated by spaces. |
hexpattern | Bit or byte pattern in hexadecimal format. A wildcard in the form X can be used in place of a digit. |
binarypattern | Bit or byte pattern in binary format. Will be displayed in hexadecimal format with the show pattern command. A wildcard in the form X can be used in place of a digit. |
decimalpattern | Bit or byte pattern in decimal format. Will be displayed in hexadecimal format with the show pattern command. |
OFfset number | Number of bytes from the pattern reference point that indicate where the pattern starts. Must be between 0 and 127. The offset value and the pattern value cannot be more than 128 bytes. If you do not enter a value, defaults to 0. |
FRom | Pattern reference point, from where the offset value is counted. Can be beginning, typefield, iphdr, tcphdr, udphdr, tcpdata, or udpdata. If you do not enter one, the default is beginning. |
BEGINNING | The beginning of the packet. |
TYPEFIELD | The beginning of the packet typefield. |
IPHDR | The beginning of the IP header. |
TCPHDR | The beginning of the TCP header. |
UDPHDR | The beginning of the UDP header. |
TCPDATA | The beginning of the TCP data. |
UDPDATA | The beginning of the UDP data. |
No patterns are configured.
System mode
Patterns can be used by all profiles.
The following example creates a pattern test1:
Host> set test1 pattern 00 5a 2c offset 10 from typefield
The following example changes the offset on the pattern test1 to 6 bytes:
Host> set test1 off 6
The following example changes the pattern name from test1 to test2:
Host> set test1 pattern test2
reset pattern
set filter
show filter
show pattern
To create a bridge filter based on packet type, use the set type command.
SEt TYpe=type [ACcept | BLock] [IGnore | DEmand]
type | Ethernet packet type. Up to four hexadecimal digits with no spaces. |
ACcept | Only packets with this packet type are forwarded to the connection. |
BLock | Packets of this type are not sent to the connection. |
IGnore | Packets of this type are not counted in the demand and timeout calculations that bring the ISDN line up and disconnect it. |
DEmand | Only packets of this type are counted in the demand and timeout calculations that bring the ISDN line up and disconnect it. |
No type filters configured.
System or profile mode
Type filters configured in system mode are used by all profiles. Type filters configured at the profile level are used by that profile only.
Although multiple type filters can be defined as accept, block, demand or ignore, the most recently defined filter determines which set of filters is used. When the packet comes in, it is evaluated by the most recent filter. If that filter blocks the packet, the packet is dropped, even if another filter would have accepted the packet.
By default, type filters apply only to broadcast and multicast packets. If unicast filtering is enabled with the set unicastfilter command, type filters apply to broadcast, multicast, and unicast packets.
Type filtering is independent of Ethernet address filtering. Packets must match address filters and type filters before being forwarded to or blocked from the ISDN line.
The following example configures profile 2503 to prevent broadcast and multicast from activating the ISDN line (however, if the ISDN line already connected, the packets are forwarded to the line):
Host:2503> set type 1 accept Host:2503> set type 1 demand
Because there are no Ethernet packets of type 1, this command blocks all broadcast and multicast traffic.
Refer to the appendix "Ethernet Packet Types" for further information.
To enable or disable unicast filtering, use the set unicastfilter command.
SEt UNicastfilter ON | OFf
ON | Enables unicast filtering. |
OFf | Disables unicast filtering. |
Off
System mode
Unicast filtering applies to type filters configured with the set type command and to user-defined filters configured with the set filter command.
The following example enables unicast filtering for the router:
Host> set unicast on
set type
set filter
show filter
To display information about the router system and profile address configurations, use the show address command.
SHow [connection] ADdressconnection | When a connection number is specified, the address associated with the connection is displayed. |
None
System or profile mode
The following example shows the output of the show address command at the system mode:
Host> show address INT0040f9120011Static LAN00a0244192fdAge:7 200001b4fb2ccAge:18 20000c075074cAge:156 26a6b1b4fb2ccAge:2162 NumberofEthernetAddresses:5 IPAddress:0.0.0.0 EthernetAddress:0040f9120011 SubnetMask:0.0.0.0 DefaultGateway:0.0.0.0 IPXDefaultGateway:NONE SAPHelper:NONE
The following example shows the output of the show address command for the profile 2503:
Host:2503> show address 2 0040f9ffffffStatic 20040f9123456Static Number of Ethernet Addresses: 2 Ethernet address: 00 40f9 0036 AD
If user profile 2503 has a connection number, entering the show connection address command displays the router profile address configuration.
Table 8-1 describes the fields shown in the display, as well as others that might appear when the command is used.
| Field | Description |
INT | Ethernet address of the internal profile |
LAN | Ethernet address of the LAN profile |
Number of Ethernet addresses | The number of Ethernet addresses associated with the system mode |
IP Address | IP address of the system mode |
Ethernet Address | Ethernet address of the router |
Subnet Mask | Subnet mask of the system mode |
Default Gateway | Default gateway of the system mode |
SAP Helper | Service advertising protocol helper |
To generate a performance report of the Ethernet interface, use the show ethernet command. The report provides information on different kinds of errors and interface traffic. The data in this report has accumulated since the router was last powered up.
SHow ETherNone
System or profile mode
The following example shows output from the show ethernet command:
Host> show ethernet Ethernet Statistics: MultipleColls:0 InternalTxErrs:0 MissedFrames:0 FramesReceived:0 FramesSent:0 OctetsReceived:0 OctetsSent:0
To display user-defined filters, use the show filter command.
SHow [id] FIlter
id |
None
In system mode, this command displays all filters configured in system mode. In profile mode, this command displays filters configured in system mode and filters defined in profile mode. This command also indicates whether unicast filtering is enabled.
The following example shows output from the show filter command:
Host> show filter Unicast Filtering OFF Filters 1 Filter BLOCK arp 3 Filter ACCEPT DEMAND john
set filter
set unicastfilter
To display all patterns configured with the set pattern command, use the show pattern command.
SHow [patternname] PATtern
patternname | Displays a specific pattern by the name assigned with the set pattern command. |
None
System mode
Patterns can be used by all profiles.
The following example shows output from the show pattern command:
Host> show pattern Patterns NameOffsetFromPattern patta6BEGINNING0003 pattb0BEGINNING0809 pattc0BEGINNING5566 pattd0BEGINNING010d 6544>
Table 8-2 defines the fields shown in the display.
| Field | Description |
|---|---|
Name | Name of the pattern. |
Offset | Number of bytes from the reference point where the pattern starts. |
From | Lists the pattern starting reference point. Can be BEGINNING or TYPEFIELD, IPHDR, TCPHDR, UDPHDR, TCPDATA, UDPDATA. |
Pattern | Byte pattern. |
To display filter types, use the show type command. Ethernet packets contain a 2-byte type field that describes the protocol type of the packet.
SHow TYpeThis command has no arguments or keywords.
None
System mode
The following example shows output from the show type command:
Host> show type TypeforwardingmodeANY TypedemandmodeANY UnicastFilteringOFF
Posted: Wed Jul 21 18:08:42 PDT 1999
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