topic Re: APA Problem when assigning IP address in Operating System - HP-UX

APA Problem when assigning IP address

PTX — Thu, 27 Mar 2008 17:38:01 GMT

I have an RX6600 running HP-UX 11.31. I have aggregated a couple of the NIC's on the server. The aggregate (lan900) seems fine.

I have another interface (lan4) on the same subnet on the server... single NIC, not aggregated.

When I assign an IP address to lan900, I lose IP connectivity lan4. Can anybody explain this behaviour?

So... if I start a ping on lan4, then...

# ifconfig lan900 up
... lan4 stops responding...
# ifconfig lan900 down
... lan4 responds again...

Thanks.

Re: APA Problem when assigning IP address

Tim Nelson — Thu, 27 Mar 2008 20:26:31 GMT

A couple questions:

1)Are the IPs the same ? ( gotta ask )
2)Are the IPs on the same subnet ?
3) How are you assigning IP to lan900, ipconfig lan900... ?

Re: APA Problem when assigning IP address

Torsten. — Thu, 27 Mar 2008 20:34:29 GMT

>> I have another interface (lan4) on the same subnet on the server

This is IMHO the problem - the same subnet ...

Re: APA Problem when assigning IP address

Tim Nelson — Thu, 27 Mar 2008 20:36:51 GMT

I hate it when Torsten reads the parts of the sentences that I overlook :) That is why he has such a cool hat.

Re: APA Problem when assigning IP address

Torsten. — Thu, 27 Mar 2008 20:44:26 GMT

Tim, you will get these few points very soon, I'm sure ...

;-)

I count on you.

Re: APA Problem when assigning IP address

PTX — Fri, 28 Mar 2008 13:52:18 GMT

IP addresses are not the same.
Subnets are the same.

I simply...

# ifconfig lan900 x.x.x.x netmask y.y.y.y in order to assign the IP address.

As far as the same subnet goes, I can't imagine it's really a problem to have two IP addresses on the same server on the same subnet. I have an rp3440 here with two IP addresses on the same subnet running fine, with access to both ip addresses... it's been like that for 3 years now.

Re: APA Problem when assigning IP address

Torsten. — Fri, 28 Mar 2008 14:06:29 GMT

There are many related threads like this one:

http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=1087227

Re: APA Problem when assigning IP address

PTX — Fri, 28 Mar 2008 14:11:42 GMT

That thread doesn't really answer my question, though it does explain something I will need, that being the ip_strong_es_model, which I would have been looking for shortly. Thank you for that.

My problem still remains that I cannot ping any IP address on the server as soon as I enable the second IP address.

Re: APA Problem when assigning IP address

Tim Nelson — Fri, 28 Mar 2008 15:51:20 GMT

My experience is that HPUX has never done well with two IPs same subnet. The route does not know which interface to go over and probably is the cause of your issue.

I would recommend lan900 one subnet, lan4 another subnet. With APA enabled the need for redundancy is resolved. The need for two separate IP addresses on a system can be resolved by using virtual IPs.

i.e.

ifconfig lan900:1 xxx.xxx.xxx.xxx blah blah blah