Change of IP Helpers in interfaces of WLC 5520

[Ignacio Sancho]

Hello,

I am trying to create an script to automate the change of the IP Helpers in the interfaces of a WLC, but I am facing an issue with the management interface.

To change this parameter in an interface, all the SSID that have the interface assigned needs to be disabled. So I disable all the SSID, change the ip helpers and enable the SSIDs again.

But the problem that I face is that the management interface that we also have configured with ip helpers, report an issue even if all the SSID are disabled. I can change it in the GUI, but I dont know what commands are executed in the background to use in my python script.

Do you have some some hints that can help me?

[Arshad Safrulla]

Hi,

What's the reason you are using DHCP proxy mode? Whats the deign object ive beind this?

DHCP bridge mode is more flexible and complaint to RFC's. This way you can do the configuration in the usptream switch/router/firewall SVI/sub-interface rather than on the controller.

[Ignacio Sancho]

Hi Arshad,

It is historical, we are not deploying new infra in proxy mode. I am changing both indeed, at wlc level where configured, and in the switch/fw when it is in bridge mode, as the configuration from controller to controller may change.   

But still facing issues with the management interface. Despite all the SSID are disabled, I can not change via CLI.

Thanks

[Rich R]

What version of software?
Is the controller in HA-SSO pair? "Note:Changing Management interface attributes are not allowed when Redudancy mode(SSO) is enabled" (AireOS spelling of redundancy, not mine!)
I might be missing something but why would you configure DHCP servers (presume that's what you mean by helper) on the management interface?

[Ignacio Sancho]

Hello,

Version is 8.10.171.0
I am just migrating from one ip of a DCHP server to another IP. So I go with my scripts for all the devices that have the old IP configured and I replace with the new one. I am not paying attention to the DHCP configuration or the logic behind each of the sites. My scope is 300 WLC.

This is an example: First I locate the interfaces that have the IP that I need to change (10.10.37.20)

interface dhcp  management primary 10.143.33.15 secondary 10.10.37.20

interface dhcp dynamic-interface SSID-1 primary 10.43.33.15 secondary 10.10.37.20 

Then I locate all the SSID that are enabled, finding wlan enable in the config.

wlan enable 1  

wlan enable 4

And I manipulate the strings to create a list of commands that I will push, first disable all the SSID that are enabled, then I change by the new ip of the dhcp server 10.20.57.20

config  wlan disable 1

config  wlan disable 4

config interface dhcp  management primary 10.143.33.15 secondary 10.20.57.20

config interface dhcp dynamic-interface SSID-1 primary 10.43.33.15 secondary 10.20.57.20

config  wlan enable 1

config  wlan enable 4

the dynamic interface works well, I am able to change it, but the management fails, reporting that it can not change it becuase the interface is attached to an SSID that is enabled, which is not true.

In GUI I can do it with no issues, but not in CLI. 

Do you know if there is a way to do it via CLI, specifically for the management interface, so I can automate it?

[Rich R]

If you can do it from GUI but not CLI then it sounds like a bug.
You could try opening a TAC case and they might have a workaround for you, although I doubt it and at this point the bug is unlikely to get fixed.
Check whether the DHCP is ever needed/used on the management interface - if not then doesn't matter that you have the old IP there.  Otherwise somebody has lots of GUI clicking to do ...

[Ignacio Sancho]

thanks for you feedback rrudling