Troubleshooting Tip: Virtual IP not reachable after network service restart

This article describes the steps to recover the Shared IP address (Virtual IP address or VIP) in L2 High Availability systems after restarting the network service.

The Virtual IP address is associated with the eth0 interface of the appliance in control (Primary Server under normal conditions). The Virtual IP association to eth0 is not persistent through network service restarts.  Consequently, if the network service is restarted, the Virtual IP address is removed from eth0 and no longer reachable.

Working example (Primary Server):

> ip addr sh dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
link/ether 00:50:56:ac:2e:82 brd ff:ff:ff:ff:ff:ff
inet 192.168.8.23/24 brd 192.168.8.255 scope global eth0
valid_lft forever preferred_lft forever
inet 192.168.8.25/24 scope global secondary eth0 <-- Virtual IP
valid_lft forever preferred_lft forever

Example after running “service network restart” on the Primary Server:
> ip addr sh dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
link/ether 00:50:56:ac:2e:82 brd ff:ff:ff:ff:ff:ff
inet 192.168.8.23/24 brd 192.168.8.255 scope global eth0
valid_lft forever preferred_lft forever
<Missing Virtual VIP entry>

There are three options to recover the Virtual IP:

Option 1 (Non-intrusive: Does not require a restart of management services):

Login to the CLI as root of the appliance in control and type
hsIP ADD <Virtual IP address> <mask CIDR format> eth0

Example:

hsIP ADD 192.168.8.25 24 eth0

Option 2: Restart management services on the appliance in control via CLI

Login to the appliance CLI as root and type
shutdownNAC

<wait 30 seconds>

startupNAC 

Option 3: Reboot Appliance via UI

1. In the Administration UI, navigate to System > Settings > System Management > Power Management.

2. Select the appliance in control and click Reboot.

Confirm the Shared IP entry has been re-added to eth0 via the CLI.  Type
ip addr sh dev eth0

Example:
> ip addr sh dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
link/ether 00:50:56:ac:2e:82 brd ff:ff:ff:ff:ff:ff
inet 192.168.8.23/24 brd 192.168.8.255 scope global eth0
valid_lft forever preferred_lft forever
inet 192.168.8.25/24 scope global secondary eth0 <-- Virtual IP
valid_lft forever preferred_lft forever

VIP should now be accessible.

For more details on High Availability, refer to the High Availability reference manual.