46-3
Catalyst 3560 Switch Software Configuration Guide
OL-8553-06
Chapter 46 Configuring Fallback Bridging
Configuring Fallback Bridging
Creating a Bridge Group, page 46-3 (required)
Adjusting Spanning-Tree Parameters, page 46-5 (optional)
Default Fallback Bridging Configuration
Tabl e 46-1 shows the default fallback bridging configuration.
Fallback Bridging Configuration Guidelines
Up to 32 bridge groups can be configured on the switch.
An interface (an SVI or routed port) can be a member of only one bridge group.
Use a bridge group for each separately bridged (topologically distinct) network connected to the switch.
Do not configure fallback bridging on a switch configured with private VLANs.
All protocols except IP (Version 4 and Version 6), Address Resolution Protocol (ARP), reverse ARP
(RARP), LOOPBACK, Frame Relay ARP, and shared STP packets are fallback bridged.
Creating a Bridge Group
To configure fallback bridging for a set of SVIs or routed ports, these interfaces must be assigned to
bridge groups. All interfaces in the same group belong to the same bridge domain. Each SVI or routed
port can be assigned to only one bridge group.
Note The protected port feature is not compatible with fallback bridging. When fallback bridging is enabled,
it is possible for packets to be forwarded from one protected port on a switch to another protected port
on the same switch if the ports are in different VLANs.
Tab l e 46-1 Default Fallback Bridging Configuration
Feature Default Setting
Bridge groups None are defined or assigned to a port. No
VLAN-bridge STP is defined.
Switch forwards frames for stations that it has
dynamically learned
Enabled.
Spanning tree parameters:
Switch priority
Port priority
Port path cost
Hello BPDU interval
Forward-delay interval
Maximum idle interval
32768.
128.
10 Mb/s: 100.
100 Mb/s: 19.
1000 Mb/s: 4.
2 seconds.
20 seconds.
30 seconds.