|
|
The x digital subscriber line bridge support feature enables you to configure a router for intelligent bridge flooding for x digital subscriber line and other bridge applications.
Downstream--Indicates the traffic flow from the server to the client. In this document, downstream defines the traffic flow from the trunk port to the subscriber port.
Subscriber Bridge Group--Bridge group formed by the subscriber interfaces.
Subscriber Policy--Set of forwarding and filtering rules applied to the subscriber bridge group.
Trunk Port--Router interface connected to the backbone routers.
Upstream--Indicates the traffic flow from the client to the server. In this document, upstream defines the traffic flow from the subscriber to the trunk port.
xDSL--Digital subscriber line; x means different media.
This feature is supported on all platforms.
To configure the router for xDSL bridge support, perform the tasks in the following sections:
To configure a subscriber bridge group, perform the following tasks, beginning in global configuration mode:
| Task | Command |
|---|---|
| Define the bridge Spanning-Tree Protocol. | bridge bridge-group protocol {ieee | dec} |
| Define a subscriber bridge group and specify the subscriber policy for the group. | bridge bridge-group subscriber-policy policy |
| Define or modify the forward and filter decisions of the subscriber policy. | subscriber-policy policy [[no] [default] packet [permit] [deny]] |
| Configure a subinterface. | interface type number |
| Assign a subscriber bridge group and indicate whether the interface is upstream or downstream from the traffic flow. | bridge-group bridge-group [subscriber-trunk] |
To monitor the subscriber bridge group, perform the following task in EXEC mode:
| Task | Command |
|---|---|
| Display the details of the subscriber policy. | show subscriber-policy policy |
| Display details of the bridge group. | show bridge [bridge-group] [interface] |
This section provides the following subscriber bridge group configuration examples:
This example uses the Fast Ethernet subinterface as the subscriber port and Frame Relay as the trunk:
bridge 1 protocol ieee # Form a subscriber bridge group using policy 1 # bridge 1 subscriber-policy 1 bridge 1 protocol ieee int fast0.1 encap isl 1 # # Put fast0.1 into subscriber group 1 # bridge-group 1 int fast0.2 encap isl 2 # # put fast0.2 into subscriber group 1 # bridge-group 1 int serial0 encap frame-relay int s0.1 point-to-point # # Use PVC 155 as the signal channel for setting up connections with the access-server # frame-relay interface-dlci 155 # # Set the trunk to go upstream # bridge-group 1 trunk
The following example uses ATM subinterfaces as the subscriber ports and the ATM as the trunk:
bridge 1 protocol ieee # # Use subscriber policy 3 # bridge 1 subscriber-policy 3 # # Change the ARP behavior from permit to deny # subscriber-policy 3 arp deny # # Change the multicast from permit to deny # subscriber-policy 3 multicast deny int atm0 int atm0.1 point-to-point # # Use AAL5 SNAP encapsulation # atm pvc 1 0 101 aal5snap bridge group 1 int atm0.2 # # Use AAL5 SNAP encapsulation # atm pvc 2 0 102 aal5snap bridge-group 1 # # Configure ATM trunk port # int atm1.1 # # Use AAL5 SNAP encapsulation # atm pvc 1 0 101 aal5snap # # Specify trunk # bridge-group 1 trunk
This section documents new or modified commands. All other commands used with this feature are documented in the Cisco IOS Release 11.3 command references.
To bind a bridge group with a subscriber policy, use the bridge subscriber-policy global configuration command. Use the no form of this command to disable the subscriber bridge group feature.
bridge bridge-group subscriber-policy policy| bridge-group | Bridge group number, in the range of 1 to 256, specified in the bridge protocol command. |
| policy | Subscriber policy number in the range of 1 to 100. |
If no forward or filter decisions have been specified for the subscriber policy, the following defaults are applied:
| Packet | Upstream |
|---|---|
| ARP | Permit |
| Broadcast | Deny |
| CDP | Deny/Disable |
| Multicast | Permit |
| STP | Deny/Disable |
| Unknown Unicast | Deny |
Global configuration
Standard access lists can coexist with the subscriber policy. However, subscriber policy will take precedence over the access list by being checked first. A packet permitted by the subscriber policy will be checked against the access list if it is specified. A packet denied by subscriber policy will be dropped with no further access list checking.
The following example forms a subscriber bridge group using policy 1.
bridge 1 subscriber-policy 1
bridge protocol
show subscriber-policy
subscriber-policy
To specify that an interface is at the upstream point of traffic flow, use the bridge-group subscriber-trunk interface configuration command. Use the no form of this command to remove the specification and reset the interface to a non-trunking port.
bridge-group bridge-group subscriber-trunk| bridge-group | Bridge group number, in the range from 1 to 256, specified in the bridge protocol command. |
The interface is set to a non-trunking port.
Interface Configuration
The following example sets bridge-group 1 as the upstream point of traffic flow:
bridge-group 1 subscriber-trunk
bridge protocol
bridge subscriber-policy
show subscriber-policy
subscriber-policy
To display the details of a subscriber policy, use the show subscriber-policy EXEC command.
show subscriber-policy range| range | Range of subscriber policy numbers (range 1 to 100). |
If a range is not specified, the entire range (1 to 100) is displayed.
EXEC
The following is sample output from the show subscriber-policy command:
Router# show subscriber-policy 1
ARP: Permit
Broadcast: Deny
Multicast: Permit
Unknown: Deny
STP: Disable
CDP: Disable
bridge protocol
bridge subscriber-policy
show bridge
subscriber-policy
To define or modify the forward and filter decisions of the subscriber policy, use the subscriber-policy global configuration command. Use the no or default form of this command to restore the default forward and filter values.
subscriber-policy policy [[no | default] packet [permit | deny]]| policy | Subscriber policy number in the range 1 to 100. |
| no | Turn off the permit for the packet (this is an equivalent of the deny keyword). |
| default | Deny forwarding of the packet (this is an equivalent of the deny keyword). |
| packet | One of the following packets:
|
|
permit | Permit forwarding of the packet. |
| deny | Deny forwarding of the packet. |
If no forward or filter decisions have been specified for the subscriber policy, the following defaults are applied:
| Packet | Upstream |
|---|---|
| ARP | Permit |
| Broadcast | Deny |
| CDP | Deny/Disable |
| Multicast | Permit |
| STP | Deny/Disable |
| Unknown Unicast | Deny |
Global configuration
As an alternative to the command syntax described above, you can enter subscriber-policy policy, followed by the specific forward or filter decisions for each packet.
The following example changes the ARP behavior and the multicast behavior from permit to deny, using the command syntax shown in the Command Syntax section:
subscriber-policy 3 arp deny subscriber-policy 3 multicast deny
The following example changes the ARP behavior and the multicast behavior from permit to deny, using the alternative syntax shown in the Usage Guidelines section:
subscriber-policy 3 arp deny multicast deny
bridge protocol
bridge subscriber-policy
show subscriber-policy
|
|