topic Same context load balancing in Application Networking

Same context load balancing

brianwhelton — Sun, 01 Dec 2013 20:03:52 GMT

Bear with me, I'm reasonable new to the ACE module, my main experience of Cisco Load Balancing was on the CSM.

Can I load balance between a group of servers and another group within the same context and in the same ip address range?

I've just taken a job where the previous guy put everything in one context.

I've recommended that the two different type of servers should be seperated into seperate contextes but we're too far down the design road for that!

Traffic will be HTTP and LDAP.

Any help really appreciated!

Same context load balancing

Kanwaljeet Singh — Sun, 01 Dec 2013 20:25:42 GMT

Hi Brian,

Inter context traffic is not allowed but you can use a L3 device to communicate across contexts.

Regarding your second question you can have the LB between the same set of IP's but you would NAT so that traffic goes through loadbalancer all the time and not directly since devices are in same subnet.

From one of the other posts:

ACE does not allow intercontext communication for security reasons. This can't be changed.

However, you can still achieve communication by going through an external gateway.

If rserver RA in vlan A of context A wants to communicate with vlan B, VIP-B, you should configure context A with a static host route, pointing VIP-B to the default gateway on the shared vlan. This default gateway will then forward the traffic to context B and for ACE it is like the connection comes from outside and not another context.

Same for the response, you need on context B a route for vlan A via the shared vlan and the gateway - not the other context.

Regards,

Kanwal

Same context load balancing

brianwhelton — Sun, 01 Dec 2013 20:32:50 GMT

Hi Kanwal

Thanks for the answer,

To clarify what I meant was this.

Only one context, host from outside sends request to the ACE modules VIP and it forwarded to servers type A (Lets say two servers A1 and A2), this works fine.

I want to know the practicalities or the request then being load balanced again from either A1 or 2 to servers type 2 (B1, B2 and B3) in the same context and ip address range before returning to the host either via servers A agin or direct.

Is that clearer?

Same context load balancing

Kanwaljeet Singh — Sun, 01 Dec 2013 20:38:59 GMT

Hi Brian,

Yeah it should work. Request from A1 or 2 would be considered as a new request and should be loadbalanced normally. Just ensure that NAT is in place so that traffic doesn't go directly to servers but via ACE for loadbalancing to work properly.

Regards,

Kanwal

Same context load balancing

brianwhelton — Sun, 01 Dec 2013 20:40:57 GMT

Thanks, I'll look into it!