I can't get a response from IPv4 dig on my server but I can get one from IPv6 dig.

See the below output:

$ dig +short myip.opendns.com a @resolver1.opendns.com
# Doesn't return anything, this used to work!
$ dig +short -4 myip.opendns.com a @resolver1.opendns.com
;; connection timed out; no servers could be reached
$ dig TXT +short o-o.myaddr.l.google.com @ns1.google.com
"2600:1700:846b:c8d0:98e5:2279:72f4:xxxx"
$ dig -4 TXT +short o-o.myaddr.l.google.com @ns1.google.com
;; connection timed out; no servers could be reached
$ dig -6 TXT +short o-o.myaddr.l.google.com @ns1.google.com
"2600:1700:846b:c8d0:98e5:2279:72f4:xxxx"

$ dig +short @8.8.8.8 google.com
;; connection timed out; no servers could be reached
$ dig +short @2001:4860:4860::8888 google.com
172.217.4.46

What the heck is going on?

I did just switched ISPs, Comcast cable => AT&T fiber and from a cable modem + router to AT&T bundled modem & router. I've never used IPv6 before this and all the IPv4 stuff worked previously for my dynamic DNS scripts from the computer I'm running this on. I'm not sure where to start looking.

EDIT: It looks like resolv.conf has the old default gateway (192.168.0.1) as the IPv4 DNS server.

$ systemd-resolve --status
# ...
Link 3 (wlp2s0)
      Current Scopes: none
       LLMNR setting: yes
MulticastDNS setting: no
      DNSSEC setting: no
    DNSSEC supported: no
         DNS Servers: 2600:1700:846b:c8d0::1
          DNS Domain: attlocal.net

Link 2 (enp0s31f6)
      Current Scopes: DNS
       LLMNR setting: yes
MulticastDNS setting: no
      DNSSEC setting: no
    DNSSEC supported: no
         DNS Servers: 192.168.0.1
                      2600:1700:846b:c8d0::1
          DNS Domain: ~.
                      attlocal.net

Using dig @192.168.0.254 google.com returns the correct value. I have no idea why it didn't change by itself. I'm just not sure how to fix it without rebooting.

For the record, I've never touched anything to do with resolv.conf and everything should be Linux Mint default. I've never manually changed the nameservers.

Also here's the output of ip -4 route

$ ip -4 route
default via 192.168.0.1 dev enp0s31f6 proto dhcp metric 20100
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown
172.18.0.0/16 dev br-7268d2f28da2 proto kernel scope link src 172.18.0.1
172.19.0.0/16 dev br-efe27a1d50a1 proto kernel scope link src 172.19.0.1
172.20.0.0/16 dev br-31f1b3063ac5 proto kernel scope link src 172.20.0.1
172.21.0.0/16 dev br-6c1ef2342a51 proto kernel scope link src 172.21.0.1
172.22.0.0/16 dev br-fca56dd8a950 proto kernel scope link src 172.22.0.1
172.25.0.0/16 dev br-6ee15f69026c proto kernel scope link src 172.25.0.1
172.26.0.0/16 dev br-2894a4b9fb39 proto kernel scope link src 172.26.0.1
192.168.0.0/24 dev enp0s31f6 proto kernel scope link src 192.168.0.230 metric 10
0
192.168.240.0/20 dev br-92e43c867623 proto kernel scope link src 192.168.240.1

$ traceroute -4n 8.8.8.8
traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets
 1  192.168.0.230  3061.133 ms !H  3061.064 ms !H  3061.023 ms !H

posted over 3 years ago

CC BY-SA 4.0

3y ago

cobertos‭

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