topic Re: AP register its hostname with DNS server? in Wireless

AP register its hostname with DNS server?

andypenning — Sun, 04 Jul 2021 03:52:04 GMT

Is it possible for a lightweight access point to dynamically register with a DNS server after it gets assigned an IP addresss from DHCP (create and update an A record with current IP address)? I would like to be able to monitor the Access Points using the hostname, without having to statically assign an IP address or use DHCP reservations.

Re: AP register its hostname with DNS server?

George Stefanick — Thu, 06 Oct 2011 20:00:49 GMT

Yes, they do. I just pinged a bunch of mine by host name. Once DHCP gives an address it learns the host name just like a PC and DNS is updated. There is nothing special you have to do.

AP register its hostname with DNS server?

andypenning — Thu, 06 Oct 2011 20:06:25 GMT

Interesting. I see the host names in DHCP but nothing in DNS. I'll see if the server team needs to change something.

thanks for the reply!

AP register its hostname with DNS server?

George Stefanick — Thu, 06 Oct 2011 20:12:21 GMT

Yea, let me clarifiy. There is nothing SPEICAL on the WLC side. This is a DHCP server thang ... . Can you ping your device by host name, assuming the wireless APs are using the same DHCP server?

Re: AP register its hostname with DNS server?

andypenning — Thu, 06 Oct 2011 20:33:27 GMT

no, I can't - thats the reason why I'm asking! . there are no DNS records for the APs. Yes they are using the same DHCP server. Windows 2008 server Active Directory-integrated DHCP and DNS. It appears that DHCP is not updating DNS for the APs.

Re: AP register its hostname with DNS server?

George Stefanick — Fri, 07 Oct 2011 03:55:45 GMT

Thanks for rating the post. Can you mark it anwsered ? It will help other should they have the same question.

AP register its hostname with DNS server?

cburton01 — Wed, 15 Aug 2012 13:42:44 GMT

I am experiencing the same in our environment with no answer. MS AD integrated DHCP & DNS with all devices obtaining IP leases and DNS records created properly but not for Cisco AP's. Even the Cisco phones have DNS records but not the AP's.

Here is the crazy part. If i ping one of my AP hostnames for example "AP649e.f3b3.5b90" i recieve a response from the Internet? The response is 67.215.65.132. How is that even possible?

Is that why my DNS server is not creating DNS records becasue that hostname exists on the Internet?

AP register its hostname with DNS server?

Stephen Rodriguez — Wed, 15 Aug 2012 14:00:14 GMT

Do you have the DHCP configured to update the A record even if hte client doesn't? (not the exact syntax)

HTH,
Steve

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AP register its hostname with DNS server?

cburton01 — Wed, 15 Aug 2012 14:29:45 GMT

I think so. Our DNS allows all updates, even unsecure.

DHCP is setup to update the DNS servers wiht A and PTR for all clients. Settings are to "Always dynamically update DNS A and PTR records" also "Dynamically update DNS A and PTR records for DHCP clients that do not request updates"

Charles

Re: AP register its hostname with DNS server?

andypenning — Wed, 15 Aug 2012 16:16:16 GMT

Charles, in my case it was a problem with the trust relationship, at least that's what the server team told me! There were a ton of "un-applied" DNS updates from DHCP, not just for the APs. They were able to fix it by opening up a case with Microsoft. hth

Andrew

AP register its hostname with DNS server?

cburton01 — Tue, 28 Aug 2012 12:21:11 GMT

It appears in my case that DNS and DHCP appear to be functioning properly.We are getting DNS records for all types of clients like iPhones, printers and android devices.

I can see that the PTR records are appearing but not the forward records.

The problem appears to be that the AP is not using the domain suffix when it is requesting to register with DNS. Its only sending the hostname according to the DNS audit log. I guess i am going to have to open a TAC Case if no one has any other ideas?

Charles

Resurrecting an old post here

Jarvis IT — Fri, 24 Oct 2014 07:32:22 GMT

Resurrecting an old post here, but also ensure you don't have a "." in the AP name. The decimal point was certainly confusing my forward record on my 2012 DHCP server, I would get a reverse lookup host name but no A record in the Forward Lookup Zone. It was a bit of an face palm moment.

Re: AP register its hostname with DNS server?

samuel.heinrich — Wed, 22 Dec 2021 11:57:35 GMT

I just want to confirm, that this is indeed the actual problem and that the answer, marked correct in this thread, is wrong.

I took a pcap on our DHCP Server. As you can see in the screenshots below

1) the DHCP Server offers option 15 including the domain name

2) the AP does not request the option 15, but only option 12 (hostname)

thus, the DNS is not updated. the AP will probably answer to ping requests on it's hostname, but that would only work within the same subnet and is not done by dns, rather by netbios i guess.