Configure Link based IPMP in Solaris

For long we used Tracking IP based IPMP wherein we track the availability of a gateway on the network using ICMP Echo request. When the gateway IP fails to respond it is considered link is unavailable and NIC fails over to the standby NIC in the IPMP group.

The biggest disadvantage here is that we use 3 IP addresses:

1 for the Virtual IP

1 for the active NIC

1 for the Standby NIC

and ofcourse the overhead of the ICMP echo requests sent every seconds.

This can be overcome using the Link based IPMP configuration where you only need only IP Address and there is no overhead of ICMP messages and the failover delay is lot lesser than that of the tracking method. And the added advantage of a very simple configuration.

To configure Link based IPMP, create the hostname.<int name> files for the Active NIC and the standby NIC. For instance here, we use the bge0 and bge3 NICs as the IPMP pair where bge0 is active and bge3 is standby and hence the files hostname.bge0 and hostname.bge3.

To configure Link based IPMP, create the hostname.<int name> files for the Active NIC and the standby NIC. For instance here, we use the bge0 and bge3 NICs as the IPMP pair where bge0 is active and bge3 is standby and hence the files hostname.bge0 and hostname.bge3.

root@solaris10:/etc # ls -l hostname*

-rw-r–r–   1 root     root          55 May  6 11:23 hostname.bge0

-rw-r–r–   1 root     root          23 May  6 11:23 hostname.bge3

Edit the hostname.bge0 file and enter the following:

root@solaris10:/etc # vi hostname.bge0

solaris10 netmask + broadcast + group sol10-ipmp up

where,

“solaris10” is the hostname which should have a corresponding host entry in the /etc/hosts file.

sol10-ipmp is the name of the IPMP group.

Edit the hostname.bge3 and the following

root@solaris10:/etc # vi hostname.bge3

group sol10-ipmp up

Here as you can see the standby NIC only has IPMP group configuration. This is all is needed to setup Link based IPMP. When the server is rebooted this configuration should take effect

To do this on the fly, we can use the ifconfig command:

NIC bge0

root@solaris10:/etc # ifconfig bge0 plumb

root@solaris10:/etc # ifconfig bge0 192.168.0.1 netmask 255.255.255.0 group sol10-ipmp up

NIC bge3

root@solaris10:/etc # ifconfig bge3 plumb

root@solaris10:/etc # ifconfig bge3 group sol10-ipmp up

root@solaris10:/etc # ifconfig -a

lo0: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4,VIRTUAL> mtu 8232 index 1

inet 127.0.0.1 netmask ff000000

bge0: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 2

inet 192.168.0.1 netmask ffffff00 broadcast 192.168.0.255

groupname sol10-ipmp

ether 0:a:1d:ee:ab:cd

bge3: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 5

inet 0.0.0.0 netmask ff000000 broadcast 0.255.255.255

groupname sol10-ipmp

ether 0:a:1d:ee:ab:d2

This should do.

To test failover, you can do the hard way of pulling the cables  or use if_mpadm command as follows:

To failover:

root@solaris10:/etc # if_mpadm -d bge0

To failback

root@solaris10:/etc # if_mpadm -r bge0