Connection remains in the ESTABLISHED state when the virtual IP is down.
From: Arkadiusz Bubała <hidden>
Date: 2016-02-04 07:51:08
Hello, I encountered following issue: when I connect with NFS server through virtual IP then I remove this IP netstat still shows that connection is ESTABLISHED. When I put down whole interface all ESTABLISHED connections disappear. The kernel version is 3.10.92. How to reproduce. create virtual IP: ip addr add 88.88.88.1/24 dev eth0 label eth0:0 (or ifconfig eth0:0 88.88.88.1) then make connection from the NFS client. In netstat there is: tcp 0 0 88.88.88.1:2049 88.88.88.2:765 ESTABLISHED- and delete virtual IP: ip addr del 88.88.88.1/24 dev eth0 (or ifconfig eth0:0 down) the netstat still shows that conneciton is ESTABLISHED and remains in that state for about 5 minutes. Even if I recreate virtual IP I can't access to the server until it disappears. When the whole interface is put down (ifconfig eth0 down) the netstat doesn't show any entries for my virtual IP and if I put it up again I can access to the server immediately. Shouldn't the ESTABLISHED connections be removed also when virtual IP is down? Or maybe there is any sysctl option to change that behaviour? -- Best regards Arkadiusz Bubała Open-E Poland Sp. z o.o. www.open-e.com