Load balancer design help

May 23, 2005 3 Replies
M

In our environment, we have a Cisco CSS 11000 that has a switch off of it. Plugged into that switch there are 2 clusters of servers. If a server in cluster 1 talks to the VIP of cluster 2, the server that receives the request in cluster 2 tries to respond directly to the server in cluster 1. The packet is then dropped. We potentially have numerous applications/servers that will fall into this scenario. What possible solutions are there to allow these servers talk to each other without getting crazy with VLANs.


_____ | LB | |_____| | ______ |Switch| |______| / \ / \ _____ _____ | 1 | | 2 | |_____| |_____|



Vote
Twitter Facebook LinkedIn
M

Any suggestions or help is much appreciated. Thanks in advance.

Vote
Twitter Facebook LinkedIn
A

Hello,

So I assume there's a direct connection between the server 1 and server 2 by passing the switch as an alternate route to the one you have trough the switch (going trough a second nic), if that is so, the what is happening is that the packet is being drop because it comes from a non valid ip address. Is routing enabled in the nics of the server? disabling may be an option.. let us know

--

2nd Law of Thermodynamics: Chaos will Reign.

///////////////////

--Anthrax-- //////////////////

snipped-for-privacy@gmail.com wrote:

Vote
Twitter Facebook LinkedIn
A

The problem with the CSS is the VIP address. The servers (will say A) will try to contact the VIP (let say VIP 1), that packet will go to CSS and it will change the destination address of the IP packet (and I do not remember what other things) with the real IP address of one of the servers (will say B). The B servers will see the source address as A (not as 1) and will reply to A withs B ip address as soruce. The servers A will say, we do not contact B, we send the packet to 1, not to B (because they are seing the source address of B, not the VIP).

What you have to do is to configure the CSS to send the packets with the IP address of the VIP as source, not as the original IP source.

-as

Anthrax wrote:

Vote
Twitter Facebook LinkedIn

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required