2 client vlan for CSM - possible?

Unanswered Question
Apr 6th, 2007
User Badges:


Is it possible that CSM has two client side vlans? The reason why i need to configure 2 client-side vlans is the ip address of the first client-side vlan is running out.



  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Syed Iftekhar Ahmed Sat, 04/07/2007 - 22:42
User Badges:
  • Blue, 1500 points or more

Yes you can definitely use mulitiple client vlans with CSM.

CSM keeps track of the MAC address from where it recieves the flow

and send the reponse from reals back there.

If you define two default gateways then you will face some routing issues. With multiple

gateways defined, CSM randomly picks one gateway. This random selection can hurt you if your reals intiate coonections.

To tackle server initiated connection issue you can use following workaround

vserver Server-side

virtual any

vlan 100 <------- server vlan where real exist

serverfarm RealX-out


serverfarm RealX-out

no nat server

real <---- Gateway that you want to use for this traffic


Hope it helps

Syed Iftekhar Ahmed

Gilles Dufour Sat, 04/07/2007 - 23:14
User Badges:
  • Cisco Employee,

you can also have a router in your first client vlan and put new vlan's behind it.

It's easier to learn 1 mac address [the one of the router] and use it for all clients [the ones behind the router].

If the CSM receives traffic from unknown mac-address it has to do a arp to fill in its arp table first and this take time.

So, if you can put your new client vlan's behind a router.



This Discussion