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Dnsmasq issues on berlin openstack cloud #715

Description

@XaverStiensmeier

When executing ping google.com dnsmasq seems to correctly forward to 8.8.8.8

ubuntu@wastefulsnake-d29e6:~$ sudo tcpdump -ni any port 53                                                            │ping: google.com: Temporary failure in name resolution
tcpdump: data link type LINUX_SLL2                                                                                    │ubuntu@wastefulsnake-d29e6:~$ 
tcpdump: verbose output suppressed, use -v[v]... for full protocol decode                                             │
listening on any, link-type LINUX_SLL2 (Linux cooked v2), snapshot length 262144 bytes                                │
11:41:23.598447 lo    In  IP 127.0.0.1.38152 > 127.0.0.1.53: 46958+ A? google.com. (28)                               │
11:41:23.598459 lo    In  IP 127.0.0.1.38152 > 127.0.0.1.53: 24680+ AAAA? google.com. (28)                            │
11:41:23.598520 enp3s0 Out IP 10.0.10.136.35177 > 8.8.8.8.53: 27665+ A? google.com. (28)                              │
11:41:23.598540 enp3s0 Out IP 10.0.10.136.40122 > 8.8.8.8.53: 36571+ AAAA? google.com. (28)                           │
11:41:28.603525 lo    In  IP 127.0.0.1.38152 > 127.0.0.1.53: 46958+ A? google.com. (28)                               │
11:41:28.603539 lo    In  IP 127.0.0.1.38152 > 127.0.0.1.53: 24680+ AAAA? google.com. (28)                            │
11:41:28.603583 enp3s0 Out IP 10.0.10.136.35177 > 8.8.8.8.53: 27665+ A? google.com. (28)                              │
11:41:28.603603 enp3s0 Out IP 10.0.10.136.40122 > 8.8.8.8.53: 36571+ AAAA? google.com. (28)                           │                                                                                                

8.8.8.8 is also reachable:

ubuntu@wastefulsnake-d29e6:~$ ping 8.8.8.8              
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.            
64 bytes from 8.8.8.8: icmp_seq=1 ttl=115 time=15.2 ms  
64 bytes from 8.8.8.8: icmp_seq=2 ttl=115 time=13.8 ms  
64 bytes from 8.8.8.8: icmp_seq=3 ttl=115 time=12.0 ms  
64 bytes from 8.8.8.8: icmp_seq=4 ttl=115 time=13.0 ms  
64 bytes from 8.8.8.8: icmp_seq=5 ttl=115 time=12.1 ms  
64 bytes from 8.8.8.8: icmp_seq=6 ttl=115 time=12.1 ms  

However, while name resolution works for registered hosts (i.e. in dnsmasq.hosts:

ubuntu@wastefulsnake-d29e6:~$ cat /etc/dnsmasq.hosts                                                                                                                             │ubuntu@nearbypanda-a54ec:~$ ls
# Master node                                                                                                                                                                    │ubuntu@nearbypanda-a54ec:~$ exit
10.0.10.136 wastefulsnake-d29e6                                                                                                                                                  │logout
10.0.10.65 nearbypanda-a54ec 
ubuntu@wastefulsnake-d29e6:~$ dig nearbypanda-a54ec                        
                                                                           
; <<>> DiG 9.18.30-0ubuntu0.24.04.2-Ubuntu <<>> nearbypanda-a54ec          
;; global options: +cmd                                                    
;; Got answer:                                                             
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 16987                  
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1    
                                                                           
;; OPT PSEUDOSECTION:                                                      
; EDNS: version: 0, flags:; udp: 1232                                      
;; QUESTION SECTION:                                                       
;nearbypanda-a54ec.             IN      A                                  
                                                                           
;; ANSWER SECTION:                                                         
nearbypanda-a54ec.      0       IN      A       10.0.10.65                 
                                                                           
;; Query time: 0 msec                                                      
;; SERVER: ::1#53(::1) (UDP)                                               
;; WHEN: Fri Mar 13 12:21:36 UTC 2026                                      
;; MSG SIZE  rcvd: 62                                                      

and also ssh ubuntu@nearbypanda-a54ec (though it takes some time), all resolutions over 8.8.8.8 fail, because it does not seem to respond which is odd given that we can ping it.

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