[lvs-users] Connections to VIPs on the same machine (in BACKUP state)

Davide Ferrari davide at trovit.com
Thu Jul 9 16:04:56 BST 2015

Hi list,

I've a doubt about how connections to a VIP initiated on the same machine
works. Let me explain with an example:
I have 2 machines (lvs1 and lvs2) with keepalived (vrrp+LVS-DR). The
cluster has a virtual server ( with some real servers behind.
lvs1 is the master and lvs2 is the backup.

The strange thing I'm seeing and that I don't understand (at least as a
feature) is that ig on lvs2 I try to connect to
it goes directly to the real servers without passing through lvs1. But is not present on any lvs2 interfaces (ifconfig, ip addr) but only
in the keepalived configuration. It's not even present in the ARP cache

I was thinking that maybe, since it's known to LVS, this IP is somewhere in
the ip_vs module and it's in earlier stage of the network stack, so any
connection to it is handled by the LVS stack as if lvs2 were the MASTER. If
I remove the virtual server from lvs2 keepalived, then a connection to from lvs2 goes to the real servers through lvs1 as expected.

Is this normal? Is this the expected behavior? If so, why?

Thank you very much

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