Back UP Cisco Controller

[m.dridi89]

Hello,

i have two controllers 2504 in different sites so differnet subnets  and i would like to make the wlc's back up each other  so when wlc 1 goes down the aps from that wlc  join the wlc2 .

 can you please tell me how that could be done ? if the ap had to be flexconnect ?

is HA  need to make the managment subnets the same or could be done in our case (differents subnets) ?

[m.dridi89]

hi,

so, in my case can i use N+1 HA ??

even that i have a different subnets and two  cisco 2504-5-K9??t if no what should i do without buying ???

[Scott Fella]

If your subnet are different because the wlc are in different locations, without buying you would need to change to FlexConnect. Otherwise you don't have any redundancy. 

-Scott

[m.dridi89]

ok 

but after studing the N+1 HA 

they told that the N+1 is deployed for to WLC in separte subnets what do they mean by that ??

how to change my controller from c2504-5 to ha-sku do i need a license or should i buy the appliance with 2504-ha-sku??

[Scott Fella]

You can't change the part number of any device. If you want to use N+1, then you need to still use FlexConnect.  It's a design thing that you need to understand. FlexConnect bs Local mode and how the traffic needs to flow. If you currently have two site with a 2504 at each location and the wireless devices get an IP address from the local site, then if you don't care that if one WLC fails and all the AP's job n the other WLC, then you need to have a large enough subnet for both sites. If you have static IP address in some devices, then they will break. So understand the traffic flow and you will be able to understand if FlexConnect is required or local mode AP's with buying redundant wlc a for each site on not. 

-Scott

[m.dridi89]

yes ,

but my question is am i able to use N+1 for my case you see 

in my first site i had 192.168.99.x for managment and the other site 10.1.99.x

is that meet my requierment to use N+1 ?? since i read that N+1 can be used for defferent subnets ??

[Scott Fella]

Management ip doesn't matter. It's your dynamic interfaces that matter unless your dumping wireless traffic in the management subnet, then it matters. 

Put it this way... If you put an ap from site 1 to the WLC in site 2, does everything work how you want it to work as far as traffic flow?  

-Scott

[Scott Fella]

Let's make it simple.  Do you not want to purchase another 2504 or is it an option. Do you have a drawing showing how the wireless is designed so we can see how the traffic flows. All your AP's are in local mode now, correct?  Knowing this info can help us tell you what you need to do, whether it is to change the AP's to FlexConnect, buy more controllers, or a mix of both. It's not going to be a simple fix because of how you have it designed currently. 

-Scott

[m.dridi89]

ok

i Have site 1  wlc mangment ip 192.168.99.250 and ap are 192.168.99.X

SSid are 192.168.60.x data 192.168.30.x guest

Site 2 wlc managment ip 10.1.99.250 ap are in 10.1.99.X

ssid 10.1.60.x data 10.1.30.x guest 

the two site are separte throw mpls link 

the idea is to establish N+1 ha so when site 1 wlc goes down the ap goes to site 2

as far as i know with flexconnect that will be possible so i have to dump local mode is that coorect ??

can you tell me is that technically possible ?? give me a solution ??

without buying a 2504-ha ?? 

AP currently in local mode and buying another controller is not an option

[Scott Fella]

So your only choice is FlexConnect then with local switching. Your going to have to trunk all the access points, create FlexConnect Groups for each site.  The vlans will need to be extended to the access switch if not already extended.  You will also need to set the primary and secondary controllers on each ap.  Hope this helps.

-Scott

[m.dridi89]

The clans will need to be extended to the access switch if not already.???

can you explain to me technically how should i do it to make N+1 ??

and what should i configure in wlc 1 and 2 ?? 

[Scott Fella]

Vlans not clans....

as far as explains what needs to be done, there is no possible way for me to document everything you need to do. All I can say is look at the various FlexConnect guides and try to understand it so you know what you need to do. Every environment is different and you have to setup your wired side first before you can change the ap mode from local to FlexConnect.  Then you need to make your changes on the controller. 

-Scott

[m.dridi89]

please stop me if i m not correct 

so the HA are two mode 

1:1 when we are using same subnet  and it s mandatory that we have device supprot HA-SKU

N+1 for backup and also need HA-sku and can use flexconnect for two different subnet 

in my case since i don t have device that support HA-SKU  so i need to buy more license for ap and other problem is since wlc1 goes down the ap when join wlc2 will broadcast ssid with the other subnet ip 10.1.60.x and 10.1.30.x ??

[Scott Fella]

You need to have enough licenses on each controller to support all access point in case of a failure. N+1 is just a redundant model. You can use an HA sku so you don't have to buy licenses or else if you want a 1:1 active active, then you need to buy licenses and again have enough licenses to support all your access points. License are not cheap either. 

-Scott

[m.dridi89]

You can use an HA sku that is mean buying an appliance with part number 2504-ha-k9 from the begining ???

[m.dridi89]

HA-sku that mean buying an appliance is there a way to convert my 2504-5-k9 to ha-sku??