dhclient append settings from multiple DHCP servers

Posted by Brian on Server Fault See other posts from Server Fault or by Brian
Published on 2011-01-17T16:41:58Z Indexed on 2011/01/17 16:55 UTC
Read the original article Hit count: 257

Filed under:

linux

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dhcp

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resolv.conf

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dhclient

I have a server with two interfaces connected to two separate networks, using DHCP for both. When dhclient is writing /etc/resolv.conf, I would like it to append settings that aren't already there. For instance, if I receive from one DHCP server:

nameserver 10.0.0.1
search one.mydomain.com

and from another:

nameserver 10.1.1.254
search two.mydomain.com

Then resolv.conf should look like this:

search one.mydomain.com two.mydomain.com
nameserver 10.0.0.1
nameserver 10.1.1.254

At the moment, it seems the last dhclient overwrites whatever was there. I know I can preconfigure settings in dhclient.conf using supercede or append, but then I have to hard-code the values. I've scoured the man page for dhclient, but it seems like dhclient prefers to work alone (i.e. not in conjunction with any other dhclients)...or am I missing something?

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