Change IP Address without rebooting in Solaris 10

Wonderful Solaris 10 huh? normally i would have to reboot the server whenever host IP is changed, now adding or editing the IP address on a Solaris 10 server need not need a reboot.

before Solaris 10, you need to edit the following files

/etc/hosts
/etc/nodenames
/etc/hostname.[device]
/etc/defaultrouter
/etc/defaultdomain
/etc/nodename

and add or modify the entries for the IP address and the hostname.

Be sure to check your /etc/netmasks too if you have network changes.

Example:
192.168.1.1 myserver

In Solaris 10, we need to edit BOTH

/etc/hosts (symlink to /etc/inet/hosts file) AND
/etc/inet/ipnodes

adding an entry for IP address and hostname plue those above mentioned ones.

Once done, do either of the following

1) svcadm restart network/physical <--- restart network service
2) reboot the server

From the man page, ipnodes file is read first before the system check hosts file. I hit this problem before when i changed the hostname/IP of a Solaris 10 server and got the network errors on my ALOM console.

Although, the /etc/inet/ipnodes files is primarily for IPv6 only, without adding an entry to the file, the IP address (IPv4) doesn’t become active in Solaris 10, at least on the release version that i'm using. This seems to be solved in Solaris 10 U4 (08/07 build).

If you need to add addresses, you must add IPv4 addresses to both the hosts and ipnodes files. You add only IPv6 addresses to the ipnodes file.