bind9 needs sometimes a restart after resume from suspend

[Rainer Dorsch <ml@bokomoko.de>]

Hello,

I run bind9 locally and noticed that bind9 sometimes needs a restart after 
suspend. This happens in rare case only though (maybe 1 out of 10 to 20 resume 
operations).

bind9 status looks ok for me:

blackbox:~# /etc/init.d/bind9 status
● bind9.service - BIND Domain Name Server
   Loaded: loaded (/lib/systemd/system/bind9.service; enabled)
  Drop-In: /run/systemd/generator/bind9.service.d
           └─50-insserv.conf-$named.conf
   Active: active (running) since Fr 2014-11-28 09:04:48 CET; 2 days ago
     Docs: man:named(8)
 Main PID: 24198 (named)
   CGroup: /system.slice/bind9.service
           └─24198 /usr/sbin/named -f -u bind
blackbox:~# dig heise.de
^Cblackbox:~#

ping on IP addresses outside of my network do work

$ ping 202.12.27.33
PING 202.12.27.33 (202.12.27.33) 56(84) bytes of data.
64 bytes from 202.12.27.33: icmp_seq=1 ttl=248 time=35.2 ms
64 bytes from 202.12.27.33: icmp_seq=2 ttl=248 time=34.9 ms
64 bytes from 202.12.27.33: icmp_seq=3 ttl=248 time=34.8 ms
64 bytes from 202.12.27.33: icmp_seq=4 ttl=248 time=34.4 ms
64 bytes from 202.12.27.33: icmp_seq=5 ttl=248 time=34.1 ms

i.e. the network connectivity seems to be ok

resolv.conf points to localhost:

blackbox:~# cat /etc/resolv.conf
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 127.0.0.1
search bokomoko.de
blackbox:~# 


I forward DNS requests to my router in named.conf.options

        forward first;
        forwarders {
              192.168.178.1;
        };

I am tempted to just restart bind9 with every resume

blackbox:/etc/bind# cat /etc/systemd/system/bind9-resume.service
[Unit]
Description=Local system resume actions
After=suspend.target

[Service]
Type=simple
ExecStart=systemctl restart bind9

[Install]
WantedBy=suspend.target
blackbox:/etc/bind#

I am not experienced in systemd setups, does that look reasonable?

Does anybody see, why bind9 in the first place sometimes needs a resume?

Many thanks,
Rainer

-- 
Rainer Dorsch
http://bokomoko.de/