ACE: VIP Out of service, Still accepts TCP connections

[paul.matthews]

Hi Guys. I am looking at a issue with an ACE. SW is 3.0(0)A3(2.6)

We have a setup where most of it appears fine. It detect the loss of rservers, probes fail, the VIP stops responding to Pings, but it still accept TCP connections, even though there is nothing behind to accept them.

The question is, is this correct behaviour? and if so is there any reference I can look at to confirm?

While this behaviour is inconvenient for us. I can see why it may actually be correct.

Thanks,

Paul.

[pevaneyn]

Hello Paul,

This is expected behaviour for L7 LB connections:

The 'down' VIP will reply to SYN requests, but will then send a RST packet.

This is because the ACE doesn't know what to do with the L7 connection until it has been build up. Only when the L7 connection is 'open' we notice that all the vserver which could serve this request are down.

So it is correct and expected, but not exactly desired. It's just a side effect of the design. So far I do not known of any plans to change this behaviour. However similar limitations have been addressed in the past, like: CSCsq17137.

Hope this helps, Peter