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New Member

large number of hsrp multicasts

I have a 6513 switch configured with 2 supervisors/msfcs. HSRP is configured and one

sup is active while the other is in standby mode.

Monitoring some of the VLANs that we've configured,

we've noticed that there is a high number of HSRP

hello packets being multicast. These multicasts outnumber broadcasts on the same VLAN/network at least 4 to 1. Should the multicast traffic be that high, and is there a way to control them?

New Member

Re: large number of hsrp multicasts

The HSRP multicasts per vlan are a function of

1) The number of vlans

2) The HSRP timers standby timers

3) If you've defined 1 HSRP group per vlan, or configured 1 HSRP group only.

I assume you have a separate HSRP group per Vlan.

If so, check the HSRP timers, hsrp groups, calculate how many broadcasts you should see & compare with normal broadcast levels.

Cheers, Ian.

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