Riverstone Networks RS Switch Router User Guide Release 8.0 8-17
ATM Configuration Guide Bridging ATM Traffic
Following are the configuration steps for the example:
8.5.1 Enabling Forced Bridging on a Virtual Channel
When Layer 3 traffic must travel through an intermediate Layer 2 cloud, such as an L2 switch, you can enable forced
bridging on ATM ports. .Enabling forced-bridging forces the VC to encapsulate all ingress/egress traffic into a Layer
2 frame. As a result, all traffic passing through the VC has a MAC address inserted into the packet header.
In the following example, forced bridging is enabled on at.5.1.1.100:
.You can also enable forced bridging on a VC group. When you do so, it applies to all VCs in the group. You cannot
enable forced-bridging on an individual basis.
8.5.2 Configuring Cross-Connects
You can configure a cross-connect on the RS to switch packets from a VC on one port to a second VC on another port.
This is similar to ATM switching functionality, but packets instead of cells are switched. To configure the
cross-connects, you need to specify the cross-connected ports. Then all traffic that is received on one VC is tunneled
to the other VC.
Apply an interface on both ethernet ports.
rs(config)# interface create ip subnetA address-netmask 11.1.1.1/24
port et.5.1 up
rs(config)# interface create ip subnetB address-netmask 11.1.2.1/24
port et.6.2 up
Create two virtual channels, one for each type of traffic.
rs(config)# atm create vcl port at.4.3.0.100
rs(config)# atm create vcl port at.4.3.0.101
Create the VLANs: VLAN A with ID number 1, and VLAN B with ID number 2.
rs(config)# vlan create VLAN_A ip id 1
rs(config)# vlan create VLAN_B ip id 2
Add the virtual channels to each VLAN.
rs(config)# vlan add ports et.5.1,at.4.3.0.100 to VLAN_A
rs(config)# vlan add ports et.6.2,at.4.3.0.101 to VLAN_B
Define a service class for VLAN A where CBR is the service category and peak cell rate is set to
100000 kcells/second to ensure proper support for video conferencing.
rs(config)# atm define service vlanA srv-cat cbr pcr 100000
Define a service class for VLAN B where UBR is the service category.
rs(config)# atm define service vlanB srv-cat ubr
Apply the appropriate service category to each VC.
rs(config)# atm apply service vlanA port at.4.3.0.100
rs(config)# atm apply service vlanB port at.4.3.0.101
rs(config)# atm set vcl port at.5.1.1.100 forced-bridged