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New Member

HSRP Timeouts

I'm having a little bit of a problem with HSRP.

We have a 2 x 3750s that us HSRP.

If i run a ping overnight to the HSRP address, I'll get about 12 packets dropped (about 40,000 were successful)

I also did a ping to both physical interfaces and they were at 100% successful

Our service provider thinks this may be normal. I think the ping to the HSRP should be %100.

I checked the interfaces, no errors.

I checked stand-by and the state hasn't changed for over 2 weeks

Its not a spanning tree issue as we don't have redundant links

I'm stumped.. any help would be appreciated

switch one:

interface GigabitEthernet1/0/6

no switchport

ip address 10.10.29.252 255.255.255.0

udld port aggressive

standby 1 ip 10.10.29.250

standby 1 timers 1 3

standby 1 priority 110

standby 1 preempt

arp timeout 900

switch two:

interface GigabitEthernet1/0/6

no switchport

ip address 10.10.29.253 255.255.255.0

udld port aggressive

standby 1 ip 10.10.29.250

standby 1 timers 1 3

arp timeout 900

4 REPLIES

Re: HSRP Timeouts

Hi Mark,

in switch two, u havn't mentioned the priority & preempt value, so without this, the switch might get confussed to make which as ACTIVE & STANDBY. hope this will be helpfull, rate this post.

New Member

Re: HSRP Timeouts

The HSRP config looks fine. You shouldn't need to specify preempt on both sides, by design preempt should only really be needed on one side, the one in which you want to be active if it's available.

The default priority is 100, and since you have set your priority to 110 on switch one, you're ok there.

What speed/duplex settings do you have on your trunk interfaces? Hard-coding these is recommended in case the autoneg process resets from time to time, which could cause very intermittent packet loss. Also check your cables/GBICs and replace on spec. If it's an etherchannel trunk be sure to check all member interfaces.

Hall of Fame Super Silver

Re: HSRP Timeouts

Mark

In the original post you describe running ping overnight to the shared address and missing a few packets and that you did ping to the interface address and got 100%. I am not clear whether the ping to the interface address was also overnight or was for a shorter duration.

You say that you checked the state on the standby and I wonder if both devices agree that the HSRP state has not changed in two weeks?

I wonder if the missing packets could be the result of something like clearing and relearning the ARP cache, you might drop a packet if it happened to hit in the time between an ARP entry being cleared and it being relearned.

HTH

Rick

New Member

Re: HSRP Timeouts

Thanks for the replies.

just so im clear… I ran the ping test to the physical interfaces for the same duration as a ran the test to the HSRP address.. the HSRP address dropped packets where as the physical interfaces were %100.

The ports are not trunks and they are not in an ether-channel group.

burts – if it was the arp cache clearing… wouldn’t I get the same problem with the physical interfaces?

I think I’ll start by hard coding the interfaces to 1000/full, ill let you know how I go

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