topic Re: Multicast MAC address in Operating System - HP-UX

Multicast MAC address

Jim Carter — Wed, 27 Mar 2002 14:37:09 GMT

Does MC/ServiceGuard 11.13 multicast MAC addresses across the networks?

Re: Multicast MAC address

melvyn burnard — Wed, 27 Mar 2002 17:40:55 GMT

Could you elaborate a bit more on the question?
SG (all versions) will re-arp the MAC address of the card which the relocatable ip address moves to, but I am not sure thaht is what you are asking

Re: Multicast MAC address

Jim Carter — Wed, 27 Mar 2002 18:15:41 GMT

The real issue deals with CampusCluster. When a package fails from one data center to another, the switches in the new data center need to learn the new IP/MAC relationship. The network manager wants to know how the switches perform this function in a < 5 minute timeframe.

Re: Multicast MAC address

melvyn burnard — Wed, 27 Mar 2002 18:50:28 GMT

This is what I thought you might be asking :-}
When the package ip gets added to a new LAN card, there is an automatic arp rebroadcast to set up the MAC/IP address relationship on network devices. This happens as the IP address is added to the network card, so virtually no delay. Wher ewe have seen problems is wher eolder net devices do NOT accept arp rebroadcasts and only refresh their arp cache after a set period of something like 10 nminutes.
HTH

Re: Multicast MAC address

Jeff Schussele — Wed, 27 Mar 2002 19:16:48 GMT

James,

I've seen the exact problem Melvyn describes on older Ciscos with outdated firmware. We've even experienced a greater level of frustration with these units ie they will even literally "lose" the floater IP from their ARP table altogether for periods FAR greater than 10 minutes - sometimes until you reassert the IP.
Only solution was to upgrade the Ciscos.

RGds,
Jeff

Re: Multicast MAC address

Jim Carter — Thu, 28 Mar 2002 14:38:51 GMT

Jeff,
Can you tell me if you experienced this issue with the Cisco 6900 series?

Re: Multicast MAC address

Jeff Schussele — Thu, 28 Mar 2002 19:05:30 GMT

James,

No, we are a large ATM/SONET based site & we were having poblems with the 12000 series switches.
These are our main switches.
But then again we had trouble from the get-go w/these switches as not all vendors are on the same page when it comes to ATM standards & we had to have a senior Cisco engineer come in & rewrite the firmware at install. So we were not sure from where our problem stemmed. This is probably why the net group was reluctant to remain current - we finally forced them to come up when the problem became untenable
We are a mixed host (SUN & HP) shop & this problem was only in our larger HP (V & K-class) & only affected the floater. This problem did not affect SUN's HA product, though - just HP MC/SG.
We always also had problems with situations when the switches would lock up or go 100% CPU such that no traffic would move. If this occurred & lasted longer that 30-45 minutes then we would HAVE to reboot the HPs & SUNs (ATM only) to clear the problem. Thank god we were a testing lab & not production....

HTH,
Jeff