If you are getting ” Starting named: /usr/sbin/named: symbol lookup error: /usr/sbin/named: undefined symbol: dns_resolver_setudpsize ” Error while starting named on Linux server then just verify your /etc/resolv.conf and then just do …..

yum -y upgrade bind-libs



If you are not able to solve it by yum command then you need to download and install the rpm bind-libs-9.2.4-16.EL4.i386.rpm
Just do this
wget ftp://ftp.pbone.net/mirror/www.startcom.org/AS-4.0.0/updates/i386/bind-libs-9.2.4-16.EL4.i386.rpm
rpm -Uvh bind-libs-9.2.4-16.EL4.i386.rpm

Others reference:
http://forums.cpanel.net/showpost.php?p=264677&postcount=18