ArubaOS and Controllers

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Occasional Contributor II
Posts: 17
Registered: ‎09-26-2008

Controller fails to detect IP conflict?

So we've had intermittent problems with a couple of our controllers and we're not entirely sure what is happening. I can see ARP entries on my router and they will reappear when I remove them, so the basic networking seems to be ok ... but I can't ping the controller when it's in this state. It might be generating ARP requests on some VLAN interfaces, but not replying on any of them. It appears as though the controller simply drops offline and there isn't much you can do except reboot it.

I ran a quick test with a spare controller under both 3.4.4.3 and 6.1.2.1 ... put a laptop online in the same network segment and forced it to have the IP of the controller. In both cases, there is nothing that would indicate there was a problem in "show log all 50" ... which (IMHO) is only the START of whatever problem I might be having here. Since there's nothing logged when I know I'm creating a problem ... there's nothing to look for when I suspect there MIGHT be a problem, right?

We have our networking gear (Cisco, Aruba, 3Com, etc.) dumping log messages to a server where we can then alert based on messages like "%IP-4-DUPADDR: Duplicate address" ... but if there isn't any messages created/sent by the Aruba gear when this happens, it seems like we're missing a very basic problem that escalates to a fairly serious one that looks like just another Aruba controller failure, no? Hell, even a Windows box can generate a error log and the popup messages that indicate you have a problem ... I really don't think I'm expecting too much here.

If there's something that we can configure to trap this, that would be great. But, I'll admit that I'm not expecting to get a config-type answer when I'm not even seeing an error message in the logs.

andrew.
Guru Elite
Posts: 20,955
Registered: ‎03-29-2007

Re: Controller fails to detect IP conflict?


So we've had intermittent problems with a couple of our controllers and we're not entirely sure what is happening. I can see ARP entries on my router and they will reappear when I remove them, so the basic networking seems to be ok ... but I can't ping the controller when it's in this state. It might be generating ARP requests on some VLAN interfaces, but not replying on any of them. It appears as though the controller simply drops offline and there isn't much you can do except reboot it.

I ran a quick test with a spare controller under both 3.4.4.3 and 6.1.2.1 ... put a laptop online in the same network segment and forced it to have the IP of the controller. In both cases, there is nothing that would indicate there was a problem in "show log all 50" ... which (IMHO) is only the START of whatever problem I might be having here. Since there's nothing logged when I know I'm creating a problem ... there's nothing to look for when I suspect there MIGHT be a problem, right?

We have our networking gear (Cisco, Aruba, 3Com, etc.) dumping log messages to a server where we can then alert based on messages like "%IP-4-DUPADDR: Duplicate address" ... but if there isn't any messages created/sent by the Aruba gear when this happens, it seems like we're missing a very basic problem that escalates to a fairly serious one that looks like just another Aruba controller failure, no? Hell, even a Windows box can generate a error log and the popup messages that indicate you have a problem ... I really don't think I'm expecting too much here.

If there's something that we can configure to trap this, that would be great. But, I'll admit that I'm not expecting to get a config-type answer when I'm not even seeing an error message in the logs.

andrew.




AFAIK, the controller does not report this.


Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Occasional Contributor II
Posts: 17
Registered: ‎09-26-2008

Re: Controller fails to detect IP conflict?




That's what I believe given the simplicity of the test and the lack of any error messages in the logs on the controller. Given how this condition makes it possible for all of the APs on a controller to quietly lose their connection to the controller and then allow all of the associated users to fall by the wayside, how would one go about getting this treated as a bug and changed in a future release of AOS ??

Guru Elite
Posts: 20,955
Registered: ‎03-29-2007

Re: Controller fails to detect IP conflict?

Please contact your local Aruba SE to open a feature request. Your request is certainly reasonable.


Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Aruba Employee
Posts: 45
Registered: ‎06-16-2009

Re: Controller fails to detect IP conflict?



Submitted


Harold
Guru Elite
Posts: 20,955
Registered: ‎03-29-2007

Re: Controller fails to detect IP conflict?

Hstonebraker, thank you.


Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

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