Cisco Systems 3560 Configuring HSRP

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Catalyst 3560 Switch Software Configuration Guide
OL-8553-06
Chapter 40 Configuring HSRP
Configuring HSRP
Multiple HSRP
The switch supports Multiple HSRP (MHSRP), an extension of HSRP that allows load sharing between
two or more HSRP groups. You can configure MHSRP to achieve load balancing and to use two or more
standby groups (and paths) from a host network to a server network. In Figure 40-2, half the clients are
configured for Router A, and half the clients are configured for Router B. Together, the configuration for
Routers A and B establishes two HSRP groups. For group 1, Router A is the default active router because
it has the assigned highest priority, and Router B is the standby router. For group 2, Router B is the
default active router because it has the assigned highest priority, and Router A is the standby router.
During normal operation, the two routers share the IP traffic load. When either router becomes
unavailable, the other router becomes active and assumes the packet-transfer functions of the router that
is unavailable.
See the “Configuring MHSRP” section on page 40-10 for the example configuration steps.
Note For MHSRP, you need to enter the standby preempt interface configuration command on the HSRP
interfaces so that if a router fails and then comes back up, preemption restores load sharing.
Figure 40-2 MHSRP Load Sharing
Configuring HSRP
These sections contain this configuration information:
• Default HSRP Configuration, page 40-5
• HSRP Configuration Guidelines, page 40-5
• Enabling HSRP, page 40-6
• Configuring HSRP Priority, page 40-7
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Active router for group 1
Standby router for group 2
Client 1
Router A Router B
10.0.0.1 10.0.0.2
Active router for group 2
Standby router for group 1
Client 2 Client 3 Client 4