C9800 Interface Group

[klnnnnng]

Hi guys,

I currently have seven /22 IP networks for my wireless clients, which are bonded in one Interface Group. Have anyone analyzed if there is some performance penalty for larger segments like broadcast/multicast traffic? What is the recommendation or best practice? What should be taken in consideration?

Thank you in advance!

Regards,

[MHM Cisco World]

Simple no need SVI in wlc9800, config SVI of vlan in l3SW not in wlc 9800

MHM

[klnnnnng]

The controller is already in bridge mode and all SVI are on the L3 Switch. 

[MHM Cisco World]

Did you think about PO between WLC and L3SW?

MHM

[klnnnnng]

Yes, Port-Channel is already up and running. I was just wondering if it is a good idea to convert the seven /22 network into one /19 network.

[MHM Cisco World]

Seven/22 for only one site or multi site?

This is guest ssid ?

This is one ssid? Or multi ssid map for same vlan?

MHM

[klnnnnng]

Only one SSID mapped with one Interface Group. 

[MHM Cisco World]

One big ssid.

So I dont recommend at all use one big vlan instead of multi vlan /22.

You can use dynamic vlan assign and use vlan group' this make each AP using same ssid but different vlan.

/19 is big any issue will effect all ssid clinets

MHM

[Leo Laohoo]

No, there is no performance penalty that we have observed and we have a lot of Interface Groups configured. 

Performance hit will depend entirely on the model of the 9800.  IF the WLC only has one WNCD, I'm not overly worried.  I am. however, terrified with WLC with multi-WNCD.  Performance hit will come from the communication between the WLC and external sources, like external authentication servers.  The hit will be in the form of continuous failed authentication attempts with external authentication server(s).  

Another is the non-stop joining/disjoining of the AP from the controllers.  

These are two examples I can quickly think of that we try as much as possible avoid happening.  

[klnnnnng]

Hi, thank you for the information. The Interface Groups are working fine, but I was just wondering if it is a good idea to convert the seven /22 network into one /19 network. Could you think of any performance or other issues?

[Leo Laohoo]

We broke ours into /23 Interface Groups.  It makes it easier to take each subnet down when we do changes, like provide new subnets, change the masks, etc.