Foundry Networks Switch and Router Installation And Configuration Manual page 865

FSRP Support on Virtual Interfaces
FSRP is supported on both physical and virtual interfaces. Support on a virtual interface allows you to assign a
single virtual interface to serve as a redundant link for multiple ports within a VLAN. For example, in Figure 22.2,
virtual interface 1 represents ports 1, 2, and 3 for NetIron1.
A virtual interface will by default remain active until all underlying links go down. If you want the virtual link to go to
FSRP standby state when a subset of the ports goes down, you must configure track ports as well.
Switch
4
IP Subnet
VLAN
3
2
1
Figure 22.2 Virtual interface providing a redundant link
Active and Standby Routers
To establish one router as active, you assign a higher preference to the router. If the preference for two routers is
equal, the interface with the higher IP address takes precedence as the active router. Link status is monitored
using a track port.
Track Ports
A track port tracks the status of the ports that are providing redundant paths. You can assign any port to be a
track port; however, a port that is providing a redundant path cannot serve as its own track port. A track port
should be assigned to track each port that is part of a virtual link. For example, in Figure 22.1, interfaces A, B, C,
and D should all be assigned track ports.
December 2000
NetIron1
(ACTIVE)
5 6 8
7
192.147.201.1
A
Virtual
A
Interface 1
Router
192.147.200.1
Switch Switch
Switch
Switch
PC1
192.147.201.50
NetIron 2
(STANDBY)
8 7 5
6
192.147.201.2
S
S
Router
Virtual
Interface 1
192.147.200.2
PC2
192.147.200.52
PC3
192.147.200.51
PC4
192.147.200.50
Configuring FSRP
Switch
4
IP Subnet
VLAN
3
2
1
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