8 Replies Latest reply: Aug 8, 2009 12:08 AM by LB RSS

    capwap vs. lwapp


      Ok, I am going over LWAPP discover and am wondering.....  If you choose to use DNS, but you are on 5.2 or newer code, then the dns record would have to be cisco-capwap-controller.localdomain instead of cisco-lwapp-controller.localdomain.  So my question is this.  If you are in an environment that had both old and new AP's, would the 5.2 code actually look to resolve both names?


      I mean, say I have a 1230 that I convert to lwapp.  When that happens, it would want to look for the cisco-lwapp-controller dns name.  Then, after joining the controller it gets its software update and then would start using capwap, if you were on the right WLC software code version.


      But, If I wanted to joint up 1140's, because they only support capwap, I would also have to have the cisco-capwap-controller.


      So in a mixed environment like this, would you just have two DNS A records, one cisco-capwap-controller and the other cisco-lwapp-controller.  and have each of them point to the same controller?  Or would you use a CNAME record?




      Anyone actually done this?

        • 1. Re: capwap vs. lwapp

          I have test it out with 2 entrys on the DNS server each pointing to the same IP and it works.

          I dont see why CNAME shouldnt work...AFAIK CNAME is linking 2 different names to one same IP right?

          • 2. Re: capwap vs. lwapp
            Jerome Henry

            Hi Jared,


            I sniffed the AP port, and it requests both CISCO-LWAPP-CONTROLLER and CISCO-CAPWAP-CONTROLLER on 5.2. Haven't tested on 6.0.

            The extension "localdomain" depends very much on your DHCP and DNS configuration, that is "does the AP receive an option 15 (domain name) from the DHCP server, and where you put your host entry in the DNS tree.

            Hope it helps



            • 3. Re: capwap vs. lwapp

              Basically the AFAIK this behavior depends on what IOS version it is running. For example if it is an RCVK IOS previous to capwap it will only do LWAPP.Once it joins to the WLC in LWAPP it takes a new IOS. k9w8 after the unit will do CAPWAP.

              As an example 1140 have an RCVK IOS that only run CAPWAP, so it should only do CAPWAP.

              • 4. Re: capwap vs. lwapp

                That is why I thought as well, however, when watching the join process, I did see a 1140 do a dns lookup for both cisco-lwapp-controller and cisco-capwap-controller....  anyhow.  I created two A records both pointing to the same controller and all seemed to work just fine.  So what I am hearing is that have two A records or an A records and a CNAME record should both work.

                • 5. Re: capwap vs. lwapp
                  Jerome Henry

                  You are correct. Having one A record for either of them works if you use 5.2.

                  If you use 5.2 on some controllers and have some APs with an earlier firmware, CISCO-LWAPP-CONTROLLER is the one to use.

                  If you plan on migrating to 6.0 and later, you can start adding a new A record or CNAME with CISCO-CAPWAP-CONTROLLER.

                  5.2 resolves both names because migrating suddenly to CISCO-CAPWAP-CONTROLLER without buffer period would obviously create issues in most networks, so this is normal and expected.

                  "Next generations" will only resolve CISCO-CAPWAP-CONTROLLER, but I do not know which release precisely.

                  • 6. Re: capwap vs. lwapp

                    Well, I am on 6.0 code now and used two A records and it seemed to work fine.  I was just wondering if really mattered if you have two A records or used a CNAME record.  It appears to me that it really doesn't matter.... as long as you have a way to resolve the name to the IP address of your controller.  My whole question was does the DNS record type matter?

                    • 7. Re: capwap vs. lwapp

                      As long as the AP could resolve the name to an IP or IPs, thats what it matter.

                      • 8. Re: capwap vs. lwapp

                        Yesterday I updated 1 controller (out of 8) to version 6.0 and changed the A record on DNS name CISCO-LWAPP-CONTROLLER to the updated controller's IP address.  I then installed an 1142 AP to test and it registered with the DNS name on the V6.0 controller with no problem.