Multiple standby groups under the same VLAN

[zarnims]

Hello,

I am a bit confused here while learning the HSRP. I'd like to say that any help on explanation is much appreciated.

I know that we can configure the standby groups for load sharing purpose on the different VLANs, but why would someone uses multiple standby groups under the same VLAN? For example I have two switches here,

sw2(config)#interface Vlan10
sw2(config-if)#ip address 10.0.0.100 255.255.255.0
sw2(config-if)#standby 1 ip 10.0.0.1
sw2(config-if)#standby 10 ip 10.0.0.10
sw5(config)#interface Vlan10
sw5(config-if)#ip address 10.0.0.101 255.255.255.0
sw5(config-if)#standby 1 ip 10.0.0.1
sw5(config-if)#standby 10 ip 10.0.0.10
sw2#show standby
Vlan10 - Group 1
  State is Standby
    1 state change, last state change 00:23:19
  Virtual IP address is 10.0.0.1
  Active virtual MAC address is 0000.0c07.ac01
    Local virtual MAC address is 0000.0c07.ac01 (v1 default)
  Hello time 3 sec, hold time 10 sec
    Next hello sent in 0.160 secs
  Preemption disabled
  Active router is 10.0.0.101, priority 100 (expires in 8.992 sec)
  Standby router is local
  Priority 100 (default 100)
  Group name is "hsrp-Vl10-1" (default)
Vlan10 - Group 10
  State is Standby
    1 state change, last state change 00:23:14
  Virtual IP address is 10.0.0.10
  Active virtual MAC address is 0000.0c07.ac0a
    Local virtual MAC address is 0000.0c07.ac0a (v1 default)
  Hello time 3 sec, hold time 10 sec
    Next hello sent in 2.144 secs
  Preemption disabled
  Active router is 10.0.0.101, priority 100 (expires in 8.960 sec)
  Standby router is local
  Priority 100 (default 100)
  Group name is "hsrp-Vl10-10" (default)
sw5#show standby
Vlan10 - Group 1
  State is Active
    2 state changes, last state change 00:20:25
  Virtual IP address is 10.0.0.1
  Active virtual MAC address is 0000.0c07.ac01
    Local virtual MAC address is 0000.0c07.ac01 (v1 default)
  Hello time 3 sec, hold time 10 sec
    Next hello sent in 1.828 secs
  Preemption disabled
  Active router is local
  Standby router is 10.0.0.100, priority 100 (expires in 7.884 sec)
  Priority 100 (default 100)
  IP redundancy name is "hsrp-Vl10-1" (default)
Vlan10 - Group 10
  State is Active
    2 state changes, last state change 00:20:19
  Virtual IP address is 10.0.0.10
  Active virtual MAC address is 0000.0c07.ac0a
    Local virtual MAC address is 0000.0c07.ac0a (v1 default)
  Hello time 3 sec, hold time 10 sec
    Next hello sent in 1.304 secs
  Preemption disabled
  Active router is local
  Standby router is 10.0.0.100, priority 100 (expires in 8.928 sec)
  Priority 100 (default 100)
  IP redundancy name is "hsrp-Vl10-10" (default)

[Steve Fuller · Accepted solution]

Hi,

MHSRP was conceived as a way of allowing hosts to utilise multiple links when they were available. For example if you have an office with two routers running HSRP between them, and each with a single WAN connection, using MHSRP would provide a way of using the bandwidth of both WAN links.

While it provided a way of using more than one link, the drawback of the feature is how different clients were configured to use the different gateway IP address.

This enhancement was added to HSRP before GLBP was available and so in its day was one way of allowing all links to be used. I guess it's of less use now with GLBP, but it may still have uses.

There's an application note Load Sharing with HSRP that explains MHSRP in more detail if you're interested.

Regards

[zarnims]

Hello Steve,

Thanks for the insight. This really helps me to get a better understanding. Have a good day.