IPV6 causing issue with DNS
- by Mike Wells
I have set up an 'internal' DNS at my work, basically we have ourdomain.com that is for internet, email etc and I have created on one of our linux network servers (debian) a DNS using bind9 with the domain ourdomain.inc.
So based on my files below and the symptoms I'm describing; what effect could IPV6 be having on my setup? What can I do to fix this?
I assume it is not actually the IPV6 causing the issue, but rather something in my setup.
These are the critical (I think) files I have modified:
named.conf.local
zone "ourdomain.inc" {
type master;
file "/etc/bind/zones/ourdomain.inc.db";
};
zone "201.168.192.in-addr.arpa" {
type master;
file "/etc/bind/zones/rev.201.168.192.in-addr.arpa";
};
named.conf.options
options {
directory "/var/cache/bind";
// If there is a firewall between you and nameservers you want
// to talk to, you may need to fix the firewall to allow multiple
// ports to talk. See http://www.kb.cert.org/vuls/id/800113
// If your ISP provided one or more IP addresses for stable
// nameservers, you probably want to use them as forwarders.
// Uncomment the following block, and insert the addresses replacing
// the all-0's placeholder.
forwarders {
1.2.3.4; //IP of our external DNS provider
};
auth-nxdomain no; # conform to RFC1035
listen-on-v6 { any; };
};
ourdomain.inc.db
$TTL 86400
ourdomain.inc. IN SOA ns1.ipower.com. admin.ourdomain.inc. (
2006081401
28800
3600
604800
38400
)
serv1 IN A 192.168.201.223
serv2 IN A 192.168.201.220
serv3 IN A 192.168.201.219
ns1.ipower.com. IN A 1.2.3.4
ns2.ipower.com. IN A 1.2.3.5
@ IN NS ns1.ipower.com.
@ IN NS ns2.ipower.com.
svn IN CNAME serv1
docs IN CNAME serv2
jira IN CNAME serv3
confluence IN CNAME serv3
fisheye IN CNAME serv3
rev.201.168.192.in-addr.arpa
$TTL 86400
201.168.192.in-addr.arpa. IN SOA ns1.ipower.com. admin.ourdomain.inc. (
2006081401;
28800;
604800;
604800;
86400
)
223 IN PTR serv1
@ IN NS ns1.ipower.com.
@ IN NS ns2.ipower.com.
named.conf
include "/etc/bind/named.conf.options";
include "/etc/bind/named.conf.local";
include "/etc/bind/named.conf.default-zones";
I then made our internal DNS my preferred DNS with the two external DNSs the next in-line. More the most part this seems to work, I can ping svn.ourdomain.inc and it resolves to the correct IP, I can also ping google.com and it also resolves no problem. So all seem good.
However, periodically (couple of times a day at least), I loose the ability to ping the svn.domain.inc (and all others defined under the internal DNS). What seem to fix the issue temporarily is to disable IPV6 on the network adapter of the client machine and then re-enable it. Then it works for a bit but will always fail again.
System Info
Internal DNS
Distributor ID: Debian
Description: Debian GNU/Linux 6.0.6 (squeeze)
Release: 6.0.6
Codename: squeeze
Linux 2.6.32-5-686 i686
BIND 9.7.3
PC
OS Name: Microsoft Windows 7 Professional
OS Version: 6.1.7601 Service Pack 1 Build 7601
System Type: x64-based PC
Network Card(s): 2 NIC(s) Installed.
[01]: Realtek PCIe GBE Family Controller
Connection Name: WORK LAN
DHCP Enabled: No
IP address(es)
[01]: the.ipv4.address
[02]: the:ipv6:address
The question...
So based on my files above and the symptoms I described; what effect could IPV6 be having on my setup? What can I do to fix this?
I assume it is not actually the IPV6 causing the issue, but rather something in my setup.
