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Community Administrator
Posts: 2,254
Registered: ‎12-03-2013

Option 43 and 60 problems

Friday, we had a weird issue arise.

 

One of the sites has a network with ~224 APs (total not model). The DHCP option 43 is pointed at the loopback for the master. Option 60 is set to Aruba Access Point. The problem is we lost about 50 APs. When investigating I discovered the APs are receiving DHCP. If i console into an AP and check the DHCP info, most all of it is correct (ip, dns, gateway, mask). However the master address wrong. They are receiving 10.0.0.0 as the master. I have checked and triple checked the options and the are correct. Any Ideas?

 

What could be the cause of this? Has anyone encountered a problem similar to this before?

CWNA, ACMP, Security +
MVP
Posts: 4,227
Registered: ‎07-20-2011

Re: Option 43 and 60 problems

Have you tried doing a trace (port mirror) and see what's been send by DHCP ?

http://www.arubanetworks.com/techdocs/ArubaOS_60/UserGuide/DHCP_Option_43.php

You shouldn't have to check this since DHCP option 43 should take precedence over any other boot method but just in case take a look at your DNS server and see what's is pointed to aruba-master.




Thank you

Victor Fabian
Lead Mobility Engineer @ Integration Partners
AMFX | ACMX | ACDX | ACCX | CWAP | CWDP | CWNA
MVP
Posts: 288
Registered: ‎08-27-2012

Re: Option 43 and 60 problems

Any chance one of the other forms of discovery is accidentally in place at that site? DNS or ADP?
ACDX #419 | ACMP |
Community Administrator
Posts: 2,254
Registered: ‎12-03-2013

Re: Option 43 and 60 problems

Thanks Guys. 

 

Victor - We do not have access to DNS at this site. This was actually my first thought when i discovered the incorrect master entry. I will definitely get to the bottom of the DNS side of discovery but being it was the start of a holiday weekend for the staff they wanted to wait till Tues to investigate.

 

 

CWNA, ACMP, Security +
MVP
Posts: 4,227
Registered: ‎07-20-2011

Re: Option 43 and 60 problems

I think you should start by sniffing the port that test AP is connect to try check option 43 / 60 value in the dhcp offer
See this screenshot

original.jpg

Thank you

Victor Fabian
Lead Mobility Engineer @ Integration Partners
AMFX | ACMX | ACDX | ACCX | CWAP | CWDP | CWNA
Community Administrator
Posts: 2,254
Registered: ‎12-03-2013

Re: Option 43 and 60 problems

Victor, you're the man! Capturing is not my strong point so this will definitely help.

 

I'll get this info first thing Tues morning.

CWNA, ACMP, Security +
MVP
Posts: 4,227
Registered: ‎07-20-2011

Re: Option 43 and 60 problems

This way you can rule out DHCP .

If the APs would have been receiving a valid IP not 10.0.0.0 , then you need to look if there's another controller in the mix that might be sending through ADP its own (that happened to me with a test controller)
Thank you

Victor Fabian
Lead Mobility Engineer @ Integration Partners
AMFX | ACMX | ACDX | ACCX | CWAP | CWDP | CWNA
Community Administrator
Posts: 2,254
Registered: ‎12-03-2013

Re: Option 43 and 60 problems

I'll verify the controller count.

 

We are in a modernization project and I was told we were ripping out the only controllers on site. You bring up a valid point though. I also have had a controller try to hijack my lab setup I just hadn't thought of it in this scenario. 

CWNA, ACMP, Security +
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