Multiple Hsrp - Cisco Catalyst 3120 Software Manual

Chapter 40 Configuring HSRP
Figure 40-1
server C

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 blade server network to a server network.
In Figure
blade servers is configured for Router B. Together, the configuration for Routers A and B establish 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
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 occurs and restores load sharing
OL-12247-01
Typical HSRP Configuration
Blade
server B
172.20.130.5
Active
router
172.20.128.1
Router A
172.20.128.32
Blade
40-2, one enclosure with blade servers is configured for Router A, and the other enclosure with
"Configuring MHSRP" section on page 40-9
Virtual Standby
router router
172.20.128.3
Router B
Blade
server A
for the example configuration steps.
Cisco Catalyst Blade Switch 3120 for HP Software Configuration Guide
Understanding HSRP
172.20.128.2
172.20.128.55
40-3