Error (Network Unreachable) Resolving

Error (Network Unreachable) Resolving

Trying to reload my bind configuration with the sudo named -g command, I get the error:

02-Aug-2018 15:42:51.472 error (network unreachable) resolving ' 2001:500:2f::f#53
02-Aug-2018 15:42:51.472 error (network unreachable) resolving ' 2001:500:2f::f#53
02-Aug-2018 15:42:51.472 error (network unreachable) resolving ' 2001:dc3::35#53
02-Aug-2018 15:42:51.472 error (network unreachable) resolving ' 2001:dc3::35#53
02-Aug-2018 15:42:51.473 error (network unreachable) resolving './NS/IN': 2001:500:2f::f#53
02-Aug-2018 15:42:51.473 error (network unreachable) resolving ' 2001:500:2d::d#53
02-Aug-2018 15:42:51.473 error (network unreachable) resolving './NS/IN': 2001:dc3::35#53
02-Aug-2018 15:42:51.473 error (network unreachable) resolving ' 2001:500:2d::d#53
02-Aug-2018 15:42:51.474 error (network unreachable) resolving './NS/IN': 2001:500:2d::d#53
02-Aug-2018 15:42:51.722 error (network unreachable) resolving ' 2001:503:eea3::30#53
02-Aug-2018 15:42:51.722 error (network unreachable) resolving ' 2001:503:83eb::30#53
02-Aug-2018 15:42:51.724 error (network unreachable) resolving './DNSKEY/IN': 2001:503:ba3e::2:30#53
02-Aug-2018 15:42:51.825 error (network unreachable) resolving ' 2001:41d0:1:4a82::1#53
02-Aug-2018 15:42:51.826 error (network unreachable) resolving ' 2001:41d0:1:4a84::1#53

The /etc/bind/149.202.46.110.in-addr.arpa file contains:

$TTL 12H
@          IN              SOA             vps36036.ovh.net. postmaster.europasprak.com. (
           2018080201      ; Serial
           8H              ; Refresh
           30M             ; Retry
           4W              ; Expire
           8H              ; Minimum TTL
)
           IN NS   vps36036.ovh.net.
           IN NS   sdns2.ovh.net.
           IN PTR  europasprak.com.

The /etc/bind/db.europasprak.com file contains:

$TTL 12H
$ORIGIN europasprak.com.
@          IN              SOA             vps36036.ovh.net. postmaster.europasprak.com. (
           2018080201      ; Serial
           8H              ; Refresh
           30M             ; Retry
           4W              ; Expire
           8H              ; Minimum TTL
)
           IN              NS              vps36036.ovh.net.
           IN              NS              sdns2.ovh.net. 
           IN              MX      10      mail.europasprak.com.
europasprak.com.  IN       A 149.202.46.110
ns         IN              A 149.202.46.110
mail       IN              A 149.202.46.110
fu         IN              A 149.202.46.110
lerum      IN              A 149.202.46.110
www        IN              CNAME           europasprak.com.
ftp        IN              CNAME           europasprak.com.
ownercheck IN              TXT             "144b57c8"

If commenting out the two lines containing the sdns2.ovh.net in each file then I get the following output (but the command then hangs):

02-Aug-2018 15:45:23.194 zone  loaded serial 2018080201
02-Aug-2018 15:45:23.197 zone  loaded serial 2018080201
02-Aug-2018 15:45:23.199 all zones loaded
02-Aug-2018 15:45:23.199 running

I need to reload the bind configuration after I added the lerum entry.

I'm on Linux data 3.2.0-4-amd64 #1 SMP Debian 3.2.68-1+deb7u5 x86_64 GNU/Linux

UPDATE: I also have that configuration listen-on-v6 { none; }; in the /etc/bind/named.conf.options file, and the configuration RESOLVCONF=no OPTIONS="-u bind -4" in the /etc/default/bind9 file. But the sudo /etc/init.d/bind9 reload command hangs. And the routes are:

stephane@data:~$ sudo route -6
Table de routage IPv6 du noyau
Destination                    Next Hop                   Flag Met Ref Use If
::1/128                        [::]                       U    256 0     0 lo
fe80::/64                      [::]                       !n   256 0     0 lo
fe80::/64                      [::]                       U    256 0     0 eth0
[::]/0                         [::]                       !n   -1  1  1385 lo
::1/128                        [::]                       Un   0   1 50901 lo
fe80::f816:3eff:fe0a:409/128   [::]                       Un   0   1     0 lo
ff00::/8                       [::]                       U    256 0     0 eth0
[::]/0                         [::]                       !n   -1  1  1385 lo

Here is the output of the ip command on the server:

stephane@data:~$ ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN group default 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether fa:16:3e:0a:04:09 brd ff:ff:ff:ff:ff:ff
    inet 149.202.46.110/32 brd 149.202.46.110 scope global eth0
    inet6 fe80::f816:3eff:fe0a:409/64 scope link 
       valid_lft forever preferred_lft forever
stephane@data:~$ ip -6 route
unreachable fe80::/64 dev lo  proto kernel  metric 256  error -101
fe80::/64 dev eth0  proto kernel  metric 256 

1 Answer

02-Aug-2018 15:42:51.472 error (network unreachable) resolving ' 2001:500:2f::f#53

This is not really related to your zone file. (Bind tries to resolve names it finds in NS records so that it could send NOTIFY messages, but the error itself is independent from what your records have.)

When you have an IPv6 address and the remote DNS server has an IPv6 address, Bind will try to contact that server via IPv6. But your network configuration is incomplete – I would guess that you have an address but you don't have a gateway (default route) configured. (Either that, or OVH's IPv6 is broken again...)

The messages should go away as soon as you fix the IPv6 connectivity on your server.

but the command then hangs

It doesn't hang. That's the 'named' server running. named -g doesn't reload configuration, it starts a new instance of the service right there on your terminal:

   -g
       Run the server in the foreground and force all logging to stderr.

To reload an existing instance, use rndc reconfig, rndc reload, or pkill -HUP named.

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Elena Rostova
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Elena Rostova

Elena Rostova holds a Master's degree in Public Health Journalism. She covers groundbreaking medical research, holistic wellness trends, mental health awareness, and nutritional science.