Does anybody know if there's any limitations or bugs to use WLC's service interface IP when add WLC into WCS?
Another question is I remember there's a post previously says that there are a bug regarding to ARP if the WLC not using LAG but connect one port to one switch, connect another port to another switch, so that's why it is strongly suggested to use LAG, but I can't find it now, anybody know it? Thanks!
On the WLC, never use SPT, if that makes it any easier.
SPT has nothing to do with being able to split your ports on the WLC. It is fully supported for at least the 440x/5508 platforms, to have one port go to switch-a and another go to switch-b. You just need to make sure you have an AP manager on each port.
The WLC does not route. We are a layer2 device not a layer3 device. IP addresses are on dynamic interfaces, so the WLC has knowledge of what the IP subnet is, in case of a L3 roam.
Spliting ports can be done for a couple of reasons, these being some semblance of balance, redundancy or to segregate traffic.
Redundancy being my client interface is normally on port 1, but is set to port 2 for backup.
Semblance of Balance, interface clients goes to port 1, interface voice goes to port 2.
Segregate, pretty much the same as SOB, but all internal would go out one port, and then my guest out the other. You could plug the "guest port" directly into a DMZ switch.
I believe we only could do 802.1d, but ever since Cisco aquired Airespace, we have not recommended enabling SPT on the controllers. This was an old piece of code that was from the older model of controller that was actually a switch, like the 4024, that actually had 24 ports on the front of it.
In later code, I want to say 5.2 and beyond, the abitlity to enable SPT has been removed.
As has been stated previously, the Service Port is designed for out of band access. You are not able to configure a gateway, so anything needing to access that interface needs to on the same subnet. Now, you can play a game with the Network Routes, these are a way to define what traffic will be forced out of the service port interface. You are not able to specify only SNMP traps, but you could try forcing all the traffic destined to the WCS out this interface.
*****BE ADVISED, THAT THIS COULD HAVE UNEXPECTED SIDE EFFECTS AS WELL. ALL TRAFFIC DESTINED FOR THE WCS WOULD BE SENT, AND YOU WOULD NO LONGER BE ABLE TO ACCESS WLC MGMT INTERFACE FROM WCS*******
that being said, I would not recommend the above be a permamnet solution, rather a short term bandaid. The management interface is designed to be used for all managment tasks.