Thank you! If forcing it to stop system-wide is not possible, is there any way of forcing IPv4 lookups to occur first then? On 4/4/2011 5:34 PM, Tom H wrote: > On Mon, Apr 4, 2011 at 10:51 AM, Russell Jones<rjones at eggycrew.com> wrote: >> I am having a strange issue with CentOS 5.4 that I cannot seem to solve. >> >> Every DNS lookup results in AAAA records being requested first before A >> records. As a result, this causes a large amount of unnecessary DNS >> traffic on the network. IPv6 has been completely disabled on these servers: >> >> /etc/modprobe.conf, ipv6 off and net-pf-10 off >> /etc/sysconfig/network, NETWORKING_IPV6=no >> >> lsmod | grep ipv6 shows the kernel module no longer loaded. >> >> Yet watching TCP dump shows that AAAA records are requested before A >> records every time a login is requested from one of our local machines >> to another. Is there some sort of configuration directive I can use to >> force IPv4 lookups first before IPv6? Or even better, stop IPv6 lookups >> all together? > Disabling ipv6 transport cannot prevent applications from making ipv6 > queries - short of recompiling them as ipv4-only applications or > having applications check whether there is a non-link-local ipv6 > address before making an ipv6 query. I've seen these checks discussed > but I don't think that they've been implemented - or, if they've been > implemented, backported to CentOS 5. It's been going on for a while: > > https://www.redhat.com/archives/redhat-list/2009-March/msg00067.html > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos >