Public bug reported: 1) Ubuntu release: 18.10 2) systemd-resolved version: (Default latest version that comes with Ubuntu 18.10) 3) Expected behavior: Comcast's POP3 mail server addresses to be resolved to IP addresses 4) Actual behavior: Comcast's POP3 mail server addresses can't be resolved to IP addresses
Starting on Monday, November 19, 2018, Comcast made a DNS change related to its POP3 mail servers (mail.comcast.net and pop3.comcast.net) that prevent resolved from being able to resolve those domains into IP addresses. When I try to ping either host (mail.comcast.net or pop2.comcast.net), I get this error: tom@deathstar:~$ ping mail.comcast.net ping: mail.comcast.net: Name or service not known tom@deathstar:~$ When I manually lookup up the domain, I get these results: tom@deathstar:~$ nslookup mail.comcast.net Server: 127.0.0.53 Address: 127.0.0.53#53 Non-authoritative answer: mail.comcast.net canonical name = imap.ge.xfinity.com. Name: imap.ge.xfinity.com Address: 96.118.242.209 Name: imap.ge.xfinity.com Address: 96.118.242.197 Name: imap.ge.xfinity.com Address: 96.118.242.233 Name: imap.ge.xfinity.com Address: 96.118.242.225 Name: imap.ge.xfinity.com Address: 96.118.242.226 Name: imap.ge.xfinity.com Address: 96.118.242.217 Name: imap.ge.xfinity.com Address: 96.118.242.208 Name: imap.ge.xfinity.com Address: 96.118.242.230 Name: imap.ge.xfinity.com Address: 96.118.242.232 Name: imap.ge.xfinity.com Address: 96.118.242.218 Name: imap.ge.xfinity.com Address: 96.118.242.211 Name: imap.ge.xfinity.com Address: 96.118.242.242 Name: imap.ge.xfinity.com Address: 96.118.242.221 Name: imap.ge.xfinity.com Address: 96.118.242.196 Name: imap.ge.xfinity.com Address: 96.118.208.40 Name: imap.ge.xfinity.com Address: 96.118.208.99 Name: imap.ge.xfinity.com Address: 2001:558:fc11:9:f816:3eff:fee8:4f07 Name: imap.ge.xfinity.com Address: 2001:558:fc11:9:f816:3eff:fe7d:1b0c Name: imap.ge.xfinity.com Address: 2001:558:fc11:9:f816:3eff:fe25:5ae5 Name: imap.ge.xfinity.com Address: 2001:558:fc11:9:f816:3eff:fef6:babc Name: imap.ge.xfinity.com Address: 2001:558:fc11:9:f816:3eff:fe87:c172 Name: imap.ge.xfinity.com Address: 2001:558:fc11:9:f816:3eff:fee6:7a57 Name: imap.ge.xfinity.com Address: 2001:558:fc11:9:f816:3eff:fe0f:a4a Name: imap.ge.xfinity.com Address: 2001:558:fc11:2:f816:3eff:fec7:cb93 Name: imap.ge.xfinity.com Address: 2001:558:fee2:1000:f816:3eff:fe42:4f14 Name: imap.ge.xfinity.com Address: 2001:558:fc18:0:f816:3eff:fe33:9aaa Name: imap.ge.xfinity.com Address: 2001:558:fc18:0:f816:3eff:feb2:8c0d Name: imap.ge.xfinity.com Address: 2001:558:fc18:0:f816:3eff:fef1:25a5 Name: imap.ge.xfinity.com Address: 2001:558:fc18:0:f816:3eff:febd:320a Name: imap.ge.xfinity.com Address: 2001:558:fc18:0:f816:3eff:fe36:aba3 Name: imap.ge.xfinity.com Address: 2001:558:fc18:0:f816:3eff:fe3f:76f2 Name: imap.ge.xfinity.com Address: 2001:558:fc18:0:f816:3eff:fe45:1d1e tom@deathstar:~$ dig mail.comcast.net ; <<>> DiG 9.11.4-3ubuntu5-Ubuntu <<>> mail.comcast.net ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 15037 ;; flags: qr rd ra; QUERY: 1, ANSWER: 17, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 65494 ;; QUESTION SECTION: ;mail.comcast.net. IN A ;; ANSWER SECTION: mail.comcast.net. 15 IN CNAME imap.ge.xfinity.com. imap.ge.xfinity.com. 12 IN A 96.117.3.119 imap.ge.xfinity.com. 12 IN A 96.117.3.96 imap.ge.xfinity.com. 12 IN A 96.117.3.143 imap.ge.xfinity.com. 12 IN A 96.117.3.145 imap.ge.xfinity.com. 12 IN A 96.117.3.129 imap.ge.xfinity.com. 12 IN A 96.117.3.148 imap.ge.xfinity.com. 12 IN A 96.117.3.201 imap.ge.xfinity.com. 12 IN A 96.117.3.136 imap.ge.xfinity.com. 12 IN A 96.118.133.238 imap.ge.xfinity.com. 12 IN A 96.117.3.128 imap.ge.xfinity.com. 12 IN A 96.117.3.144 imap.ge.xfinity.com. 12 IN A 96.117.2.238 imap.ge.xfinity.com. 12 IN A 96.117.3.110 imap.ge.xfinity.com. 12 IN A 96.117.3.140 imap.ge.xfinity.com. 12 IN A 96.117.3.154 imap.ge.xfinity.com. 12 IN A 96.117.3.132 ;; Query time: 13 msec ;; SERVER: 127.0.0.53#53(127.0.0.53) ;; WHEN: Tue Nov 20 06:58:31 PST 2018 ;; MSG SIZE rcvd: 334 tom@deathstar:~$ Before November 19, 2018, everything was working fine. The initial indication there was a problem was Mozilla Thunderbird failed to connect to Comcast's POP3 mail server. Once I did some investigation, I found the information above. I have since disabled system-resolved and have installed "Unbound". After installing "Unbound", I'm able to ping "mail.comcast.net" without issue and Mozilla Thunderbird can contact successfully Comcast's POP3 mail servers. I started a thread about this on Ubuntuforums.org: https://ubuntuforums.org/showthread.php?t=2406399 and others report being impacted by this as well. Let me know if more information is needed! Thanks! ** Affects: systemd (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1805027 Title: systemd-resolved can't resolve Comcast mail server addresses To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1805027/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
