Bind 9, network unreachable in /log/messages

Have a strange thing I run virtualmin on my system has bind etc setup but I don’t do any public DNS stuff its only for my local lan.

I checked some logs out of interest and noticed Bind9 is spewing network unreachable messages on load.

The amount of messages is too long (a few hundred lines of it) so here is the start of bind to a few of these messages.

Everything is pretty much a default install my dms enteries are my ISP ones with my server (itself) 127.0.0.1 and 192.168.1.1 listed first.

My search DNS server is set as itself was set to my isp for some reason I think postfix did that as I use my external hostname which is my-static-ip.ispdomain.com.au.

Apart fromt that I don’t know how to fix this or turn whatever feature off if I don’t need it.

Any clues on this?

Jul 7 20:51:42 server named[15364]: ---------------------------------------------------- Jul 7 20:51:42 server named[15364]: BIND 9 is maintained by Internet Systems Consortium, Jul 7 20:51:42 server named[15364]: Inc. (ISC), a non-profit 501(c)(3) public-benefit Jul 7 20:51:42 server named[15364]: corporation. Support and training for BIND 9 are Jul 7 20:51:42 server named[15364]: available at https://www.isc.org/support Jul 7 20:51:42 server named[15364]: ---------------------------------------------------- Jul 7 20:51:42 server named[15364]: adjusted limit on open files from 4096 to 1048576 Jul 7 20:51:42 server named[15364]: found 2 CPUs, using 2 worker threads Jul 7 20:51:42 server named[15364]: using up to 4096 sockets Jul 7 20:51:42 server named[15364]: loading configuration from '/etc/named.conf' Jul 7 20:51:42 server named[15364]: reading built-in trusted keys from file '/etc/named.iscdlv.key' Jul 7 20:51:42 server named[15364]: using default UDP/IPv4 port range: [1024, 65535] Jul 7 20:51:42 server named[15364]: using default UDP/IPv6 port range: [1024, 65535] Jul 7 20:51:42 server named[15364]: listening on IPv6 interfaces, port 53 Jul 7 20:51:42 server named[15364]: listening on IPv4 interface lo, 127.0.0.1#53 Jul 7 20:51:42 server named[15364]: listening on IPv4 interface eth0, 192.168.1.1#53 Jul 7 20:51:42 server named[15364]: generating session key for dynamic DNS Jul 7 20:51:42 server named[15364]: sizing zone task pool based on 12 zones Jul 7 20:51:42 server named[15364]: using built-in DLV key for view _default Jul 7 20:51:42 server named[15364]: set up managed keys zone for view _default, file '/var/named/dynamic/managed-keys.bind' Jul 7 20:51:42 server named[15364]: Warning: 'empty-zones-enable/disable-empty-zone' not set: disabling RFC 1918 empty zones Jul 7 20:51:42 server named[15364]: automatic empty zone: 127.IN-ADDR.ARPA Jul 7 20:51:42 server named[15364]: automatic empty zone: 254.169.IN-ADDR.ARPA Jul 7 20:51:42 server named[15364]: automatic empty zone: 2.0.192.IN-ADDR.ARPA Jul 7 20:51:42 server named[15364]: automatic empty zone: 100.51.198.IN-ADDR.ARPA Jul 7 20:51:42 server named[15364]: automatic empty zone: 113.0.203.IN-ADDR.ARPA Jul 7 20:51:42 server named[15364]: automatic empty zone: 255.255.255.255.IN-ADDR.ARPA Jul 7 20:51:42 server named[15364]: automatic empty zone: 0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.IP6.ARPA Jul 7 20:51:42 server named[15364]: automatic empty zone: D.F.IP6.ARPA Jul 7 20:51:42 server named[15364]: automatic empty zone: 8.E.F.IP6.ARPA Jul 7 20:51:42 server named[15364]: automatic empty zone: 9.E.F.IP6.ARPA Jul 7 20:51:42 server named[15364]: automatic empty zone: A.E.F.IP6.ARPA Jul 7 20:51:42 server named[15364]: automatic empty zone: B.E.F.IP6.ARPA Jul 7 20:51:42 server named[15364]: automatic empty zone: 8.B.D.0.1.0.0.2.IP6.ARPA Jul 7 20:51:42 server named[15364]: command channel listening on 127.0.0.1#953 Jul 7 20:51:42 server named[15364]: command channel listening on ::1#953 Jul 7 20:51:42 server named[15364]: zone 192.168.1.1/IN: loaded serial 1404711189 Jul 7 20:51:42 server named[15364]: zone 110.175.205.112/IN: loaded serial 1404639189 Jul 7 20:51:42 server named[15364]: zone 0.in-addr.arpa/IN: loaded serial 0 Jul 7 20:51:42 server named[15364]: zone 1.0.0.127.in-addr.arpa/IN: loaded serial 0 Jul 7 20:51:42 server named[15364]: zone 1.168.192.in-addr.arpa/IN: loaded serial 1404710825 Jul 7 20:51:42 server named[15364]: zone 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa/IN: loaded serial 0 Jul 7 20:51:42 server named[15364]: zone localhost.localdomain/IN: loaded serial 0 Jul 7 20:51:42 server named[15364]: zone localhost/IN: loaded serial 0 Jul 7 20:51:42 server named[15364]: zone drguild2.noip.me/IN: loaded serial 1404712277 Jul 7 20:51:42 server named[15364]: zone cajgo-support.sytes.net/IN: loaded serial 1404730284 Jul 7 20:51:42 server named[15364]: zone server.revnet/IN: loaded serial 1404637610 Jul 7 20:51:42 server named[15364]: managed-keys-zone ./IN: loaded serial 59 Jul 7 20:51:42 server named[15364]: running Jul 7 20:52:06 server named[15364]: error (network unreachable) resolving 'www.googleapis.com/A/IN': 2001:503:c27::2:30#53 Jul 7 20:52:06 server named[15364]: error (network unreachable) resolving './NS/IN': 2001:503:c27::2:30#53 Jul 7 20:52:06 server named[15364]: error (network unreachable) resolving 'www.googleapis.com/A/IN': 2001:503:231d::2:30#53 Jul 7 20:52:07 server named[15364]: error (network unreachable) resolving 'com/DNSKEY/IN': 2001:503:a83e::2:30#53 Jul 7 20:52:08 server named[15364]: error (network unreachable) resolving 'www.googleapis.com.dlv.isc.org/DLV/IN': 2001:500:f::1#53 Jul 7 20:52:08 server named[15364]: error (network unreachable) resolving 'www.googleapis.com.dlv.isc.org/DLV/IN': 2001:4f8:0:2::19#53 Jul 7 20:52:09 server named[15364]: error (network unreachable) resolving './NS/IN': 2001:503:ba3e::2:30#53 Jul 7 20:52:09 server named[15364]: error (network unreachable) resolving 'ns1.isc.ultradns.net/A/IN': 2001:503:ba3e::2:30#53 Jul 7 20:52:09 server named[15364]: error (network unreachable) resolving './NS/IN': 2001:dc3::35#53 Jul 7 20:52:09 server named[15364]: error (network unreachable) resolving 'ns1.isc.ultradns.net/AAAA/IN': 2001:503:ba3e::2:30#53

Howdy,

The domains it said it had a problem resolving – are you able to resolve them now?

For example, if you run the command “host domain.tld” for some of those domains, does it list an IP address?

-Eric

Looks like the network errors you’re getting refer to IPv6 addresses. Do you use IPv6 on your server? If not, you can instruct BIND to only use IPv4 by adding the option “-4” to its startup parameters. On Debian/Ubuntu, those are located in the file /etc/default/bind9.

After posting I realised its a IPV6 message, the solutions I found were to edit ones grub info. Also that most ISP’s in the world still don’t use IPV6 yet even though the official world switch on was last year I believe.

There’s even talk of ISP’s using carrier IPV4 nat just to get a extra 20+ more years out of IPV4.

So a update to webmin/virtualmin has a option to disable IPV6 from things as most users I would presume a good majority on here don’t use IPV6 yet.

I looked in bind under module config and turned off IPV6 support in display options I presume thats visual only as it didn’t do anything, also there’s no file in that folder on Centos.

I’ll do some digging around and see if I can find the option.

No option in webmin itself.

Only thing I can see on a look at the settings files is in named.conf

listen-on-v6 port 53 { any;

Turning off IPv6 support in BIND is indeed not done via its usual config files, and Webmin IIRC doesn’t have an option for it.

It needs to be done via the startup parameters passed to the BIND executable by the start script. On Debian/Ubuntu, this is done in the file I mentioned. Eric will hopefully know where CentOS hides those options. :slight_smile:

I did a quick Google and followed the guide here for that perameter which seems to have worked.

The file was called in ‘named’ in ’ /etc/sysconfig/’

Be nice for Webmin to add it in as a option in the interface, cause what’s the point having the option not available to end users easily accessible who’s ISP’s haven’t enabled ipv6 yet when without it there messages logs are going to be filled with network unavailable messages?

The only reason I noticed it when checking the logs for anything unusual with the bootup as the console screen size changed on a reboot from what it was to something a little smaller using ‘HP KVM Viewer’ (I presume its due to a kernel update post install) which I’m not going to worry about I don’t need console much as I have SSH etc and only use remote native console for rare occasions.