Univention Bugzilla – Bug 36681
nscd breaks IPv6 ping6
Last modified: 2018-04-13 13:32:25 CEST
root@h70:~# getent hosts h70.phahn.pt 2001:4dd0:ff00:8c42:ff17::3 h70.phahn.pt root@h70:~# getent hosts h70 2001:4dd0:ff00:8c42:ff17::3 h70.phahn.pt root@h70:~# dig h70.phahn.pt ; <<>> DiG 9.8.4-rpz2+rl005.12-P1 <<>> h70.phahn.pt ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 8381 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 3 ;; QUESTION SECTION: ;h70.phahn.pt. IN A ;; ANSWER SECTION: h70.phahn.pt. 80600 IN A 10.200.17.70 ;; AUTHORITY SECTION: phahn.pt. 10800 IN NS h72.phahn.pt. phahn.pt. 10800 IN NS h70.phahn.pt. phahn.pt. 10800 IN NS h71.phahn.pt. ;; ADDITIONAL SECTION: h70.phahn.pt. 80600 IN AAAA 2001:4dd0:ff00:8c42:ff17::3 h71.phahn.pt. 172800 IN A 10.200.17.71 h72.phahn.pt. 172800 IN A 10.200.17.80 ;; Query time: 1 msec ;; SERVER: 10.200.17.70#53(10.200.17.70) ;; WHEN: Fri Nov 14 10:27:25 2014 ;; MSG SIZE rcvd: 156 root@h70:~# ping6 -c 1 h70.phahn.pt unknown host root@h70:~# ping6 -c 1 2001:4dd0:ff00:8c42:ff17::3 PING 2001:4dd0:ff00:8c42:ff17::3(2001:4dd0:ff00:8c42:ff17::3) 56 data bytes 64 bytes from 2001:4dd0:ff00:8c42:ff17::3: icmp_seq=1 ttl=64 time=0.038 ms --- 2001:4dd0:ff00:8c42:ff17::3 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.038/0.038/0.038/0.000 ms root@h70:~# nscd -i hosts root@h70:~# ping6 -c 1 h70.phahn.pt unknown host root@h70:~# /etc/init.d/nscd stop [ ok ] Stopping Name Service Cache Daemon: nscd. root@h70:~# ping6 -c 1 h70.phahn.pt PING h70.phahn.pt(h70.phahn.pt) 56 data bytes 64 bytes from h70.phahn.pt: icmp_seq=1 ttl=64 time=0.037 ms --- h70.phahn.pt ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.037/0.037/0.037/0.000 ms
With UCS-4.1-0 it works. I think its related to the sequence number not being updated in non-S4-environments. 1. getent first goes to /etc/hosts, which contains the IPv6 address of the host itself. 2. dig goes to the DNS server first. 3. After doing a dummy change on the zone, the proxy fetched the zone and after that it worked: # getent hosts $(hostname -f) 2001:4dd0:ff00:8c42:ff17:5254:7b:2735 dc0.phahn.pt dc0 # getent hosts $(hostname) 2001:4dd0:ff00:8c42:ff17:5254:7b:2735 dc0.phahn.pt dc0 # dig +noall +answer +search -t any $(hostname -f) dc0.phahn.pt. 80600 IN AAAA 2001:4dd0:ff00:8c42:ff17:5254:7b:2735 dc0.phahn.pt. 80600 IN A 10.200.17.39 # ping6 -c 1 $(hostname -f) 1 packets transmitted, 1 received, 0% packet loss, time 0ms