Originally posted by: SystemAdmin

Our p550 (w AIX5.3L OS)has dual NIC on board. My questions are:
Is it worthy to activate both NIC with different IP on each, so that the system can continue function when one of the NIC fail?
How and where can I find the process (info) to set it up?
Do my applications on board need to do anything else to match the implementaion, ie. I have BAAN and Oracle servers on the box, when dual NIC in action, how the application switch the NIC service?
I have zero knowledge this. I read some others abou the dual NIC, some recommeded and some believe watching out the failure of HD or other hardware is more critical.
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Originally posted by: orphy

Etherchannel might be a good option for you.

http://publib.boulder.ibm.com/infocenter/systems/index.jsp?topic=/com.ibm.aix.commadmn/doc/commadmndita/etherchannel_intro.htm&tocNode=int_3531
Orphy
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Originally posted by: pvaughan

For availability, you may want to use both NICs. But, I assume you have dual NICs in one CEC, the chances of the actual port failing are pretty slim. There is a much better chance of a network issue down the line. I would activate both NICs and bond them together with Etherchannel if your network infrastructure will allow you to span an Etherchannel connection across switches. That way you connect one NIC to one switch and another to a second switch (assuming your have redundant networks) and bond them together for double the throughput and if one network fails the other stays running. There is quite a bit of information on Etherchannel in some of the RedBooks.

Another option is HACMP, though it's not free. With HACMP, you can have an IP address that the system will swap from the adapter that has failed to the adapter that's still available. But, you're going to need some expertise in your shop to see if that's a viable option.

If you're using Oracle 10G, there is IP takeover built in. I'm not running 10G yet, so I can't help you too much there.

And, finally, you can activate both NICs with different IPs. Then in the event of a failure you can alias the production IP to the available NIC manually.

Most applications either have a file that lists the IPs to listen on, or will listen on all the available IPs when the processes startup. With Oracle, the IP that the client's use is controlled by the TNSNames file, I'm not sure how that would work with BAAN.

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Originally posted by: SystemAdmin

see the other responses about etherchannel. we use this on all servers, it's great.

one nitpicking thought about the 2 on-board interfaces: they're served by the same chip on the motherboard. for highest availability, make your etherchannel pair out of one on-board and one interface on an expansion card.

again, that's only if you're just obsessed with availability
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Originally posted by: SystemAdmin

How you use a second NIC depends on what's important to you. You've already alluded to availability. Otherwise you can use a second NIC independently to support parallelism or to avoid one application overwhelming other work. A common example would be to have a separate network set up to run your backups over so they don't get in the way of regular users.

Regards,
Jim Lane
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