CCNP - Virtual Mac-address

Author

Virtual Mac-address

beenframed

2001-08-23, 5:14 pm

situation:

HSRP is running, on two cisco 3600. Inside of them is a set of redundant switches and inside of them is a set of redundant firewall. All Cisco stuff. The firewalls cannot pick up the virtual mac address of the HSRP. Booting the routers resolves the issue and the firewalls have the mac in there arp tables. But after the arp entry times out it does'nt pick that address up again? We've hard coded the virtual-mac onto the pix and that seems to be a good band aid fix but does'nt explain to us why the pix cannot refresh its arp with the HSRP virtual-mac.

Any ideas?

Thanks,

-bf

MadChef

2001-08-23, 9:00 pm

I've never had a problem getting pix's to talk to an HSRP address, and I've done it often. There isn't anything inherently wrong with what you're doing.
I might start looking at the bug list for the codes you're running.

MadChef

depamo

2001-08-24, 1:03 pm

Should pop right in, never had a problem either. So either the HSPR router that is active doesn't send the MAC or the PIX isn't asking for it again.

I would go over your commands for those ports and make sure that your commands are right. If all checks out and there are not bugs listed, make sure the IOS versions are the same on both 3600's. If that fails, grab a protocol analyzer and see who isn't participating in keeping the MAC adddress updated.

Also might try to check out the CDP information. CDP packets should be shooting back and forth keeping the ARP hot. Not sure off the top of my head but I do believe that you can use the debug command to look at CDP transactions between the two. Assuming that you are using 100Mb/s MultiAccess Ethernet.

There are some debug commands -

http://www.cisco.com/univercd/cc/td...d301c.htm#33018

Hope that at least will give you some ideas or point you in the right direction.

007

2001-08-24, 2:29 pm

Hey Im not sure if this relates to routers running your platform, but I know there is a known bug related to virtual MAC, when HSRP is configured on MSFC's. You definatly want to call Cisco, because im positive there is a bug like this......

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