Welcome, time traveler! Since we are just finishing living June, 2009,
could you be so kind to post the original problem? Otherwise we will
have to wait until September before being able to answer your question.
Regards,
Andrey.
What is the problem occuring on? You losing pings, or complete
traffic to a particular IP? Anything unique on the boxes being
impacted, i.e. load balancing, multicast, etc? Short answer is,
perhaps there is load balancing and one of your boxes is having a
problem. and clearing arp is the only thing that is forcing the usage
of the other box in the cluster (which would have a different mac). I
agree with your overall assessment of how things should work, but I
would not be convinced that you have something in the mix that is
making it behave differently. Here is a good link from cisco in the
meantime:
http://www.cisco.com/en/US/products/hw/switches/ps708/products_tech_note09186a00807347ab.shtml
That's pretty funny, Andrey !
The reason setting the ARP cache timeout and the CAM timeout to the same
value fixes this problem is because when CAM table entry expires, so does
the ARP entry. The router will then ARP the client and both tables get
refreshed. The key to this problem is that both the ARP and CAM table
timeout values are reset only when a packet is received from the client, not
when one is sent to it.
It is a Cisco recommended practice to always set the ARP and CAM timeouts to
the same value when running HSRP in order to prevent this problem. There
is debate as to weather you should lower the ARP timeout or raise the CAM
timeout. I always lower the ARP timeout to match the CAM timeout, which is
300 seconds.
"Gabriele Guasco" <gabriel...@gmail.com> wrote in message
news:9f6a615c-8ffe-4c77...@e39g2000yqh.googlegroups.com...