So, you’re trying to get here:
/etc/resolv.conf: nameserver 192.168.1.1 domain aaa.com search aaa.com bbb.com
You need to edit dhclient.conf like this:
/etc/dhcp3/dhclient.conf: supersede domain-name-servers 192.168.1.1; supersede domain-name "aaa.com"; append domain-name " bbb.com";
There must be a space before the bbb.com
Then run dhclient:
# /sbin/dhclient Internet Systems Consortium DHCP Client V3.1.3 Copyright 2004-2009 Internet Systems Consortium. All rights reserved. For info, please visit https://www.isc.org/software/dhcp/ Listening on LPF/eth0/00:1b:78:a9:4a:a4 Sending on LPF/eth0/00:1b:78:a9:4a:a4 Sending on Socket/fallback DHCPREQUEST of 192.168.1.19 on eth0 to 255.255.255.255 port 67 DHCPACK of 192.168.1.19 from 192.168.1.1 bound to 192.168.1.19 -- renewal in 42626 seconds.
Then look at your new resolv.conf.
