Hey Kenneth, Try to fully disable IPv6 while adding: alias net-pf-10 off alias ipv6 off to /etc/modprobe.conf and to /etc/sysconfig/network NETWORKING_IPV6=no This should probably solve the problem (at least IPv6 is turned off) Cheers, Si >-----Original Message----- >From: redhat-list-bounces@xxxxxxxxxx >[mailto:redhat-list-bounces@xxxxxxxxxx] On Behalf Of Kenneth Holter >Sent: Monday, March 09, 2009 4:17 PM >To: redhat-list@xxxxxxxxxx >Subject: Strange IPv6 DNS lookups > >Hello all. > > >Several of our RHEL-servers are issuing strange DNS lookups. >Consider this >example: > > >* 1 0.000000 1.2.3.4 -> 5.6.7.8 DNS Standard query AAAA ** >server1.example-prod.com* <http://server1.example-prod.com/>* > 9 0.007891 1.2.3.4 -> 5.6.7.8 DNS Standard query AAAA >server1.example-prod.com.example-test.local > 11 0.092904 1.2.3.4 -> 5.6.7.82 DNS Standard query A >server1.example-prod.com > 12 0.093356 5.6.7.8 -> 1.2.3.4 DNS Standard query >response A 1.2.3.4 >* > >>From what I can tell, the client first issues two IPv6 DNS >lookups, before >falling back to IPv4 lookup. We're not running IPv6 (and our >DNS servers do >not support IPv6 lookups), so the client is not getting and >answer before >issuing the IPv4 lookup. > >I've very puzzled by the second query, in which the FQDN of >the lookup query >is appended another domain. I've noticed that the appended >domain may be >both the same domain name (i.e. >server1.example-prod-com.example-prod.com) >or another domain as in the example above. >Does anyone have a clue as to why such bizarre queries are >performed by the >client? > >Since we're not running IPv6, I have simply disabled it for this server >(grepping "lsmod" does not return any "ipv6" results). Yet the problem >remains. Does the DNS lookup library automatically issue IPv6 >queries before >issuing IPv4 queries? Is there a way to disable IPv6 lookups? > > >Regards, >Kenneth Holter >-- >redhat-list mailing list >unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe >https://www.redhat.com/mailman/listinfo/redhat-list > -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
