mac address and multiple nic cards question

[dandan123]

We have two nic cards on all our servers. One nic is connected to production and the other to the backup segment used to backup the servers using netbackup.

We are currently troubleshooting network congestion when backups run.

Most of the servers are set up to have one mac address for both nics which our networking guys are telling us is not correct.

I'm trying to get a better understanding of using a single mac address as opposed to different mac addresses for each card.

Under what circumstances would you use a single mac/multiple macs ?

TIA

 

[daFranze]

>> Under what circumstances would you use a single mac/multiple macs?

as long as the NICs are not connected to the same switch/router/hub there is no need to set individual macs; if it is connected to the same piece of HW I suggest to set local-mac-address? true, even if you use VLANs

Best Regards, Franz
--
UNIX System Manager from Munich, Germany

 

[mrn]

From experience this sounds more like a speed mis-match between nic & switch. Don't set to auto neg try 100/Full on both ends.

Mike

"Whenever I dwell for any length of time on my own shortcomings, they gradually begin to seem mild, harmless, rather engaging little things, not at all like the staring defects in other people's characters."

 

[dandan123]

Franze..thanks for that piece of info. The two nics go to different switches, at least that's what the network guys tell us.

mrn..it's not a speed mis-match issue, we're using 1000/full on most of them.