[outages] Comcast public-facing DNS servers unreachable

[Jeremy Chadwick]

Looks like Comcast's public-facing DNS servers aren't responsive.

MXToolbox and a couple other DNS-related sites confirm this, but a
simple dig +trace is sufficient as well.

$ dig +trace pop3.comcast.net
{snipping for brevity}
;; Received 1173 bytes from 192.203.230.10#53(e.root-servers.net) in 11 ms

comcast.net.            172800  IN      NS      dns101.comcast.net.
comcast.net.            172800  IN      NS      dns102.comcast.net.
comcast.net.            172800  IN      NS      dns103.comcast.net.
comcast.net.            172800  IN      NS      dns104.comcast.net.
comcast.net.            172800  IN      NS      dns105.comcast.net.
comcast.net.            86400   IN      DS      40909 5 2 30C0F50E68DCC9A2F279A994C07CF22CED97AADF44C2B1FE38A1B32B A1A34174
comcast.net.            86400   IN      DS      40909 5 1 DDC19733884EE533B35B4B57717BEA9B0EF2C4D1
comcast.net.            86400   IN      RRSIG   DS 8 2 86400 20230404061502 20230328050502 27254 net. btO4iRmoCjqgYlgZPCORiX7soM6Twg610wTSCdD/sxizsoLoWeB+vBXY mChMJmrhGenkhJroQoriY1FyMDl4EvcTyKRDYG3c8HL0p8ILo4kJAOWi CSAt/qB76i21+8SmLsvhE0bPuUUQQXv69vfDfjxxYVsAbbMGfTLvHNJT BX3B6CrqNzXARN2dpDaUsb/8r3i0ve9byu/Sur2vZIYjwg==
couldn't get address for 'dns101.comcast.net': not found
couldn't get address for 'dns102.comcast.net': not found
couldn't get address for 'dns103.comcast.net': not found
couldn't get address for 'dns104.comcast.net': not found
;; Received 649 bytes from 192.48.79.30#53(j.gtld-servers.net) in 15 ms


-- 
| Jeremy Chadwick                              jdc_at_koitsu.org |
| UNIX Systems Administrator                      PGP 0x2A389531 |
| Making life hard for others since 1977.                        |