We (AS22578) are unable to reach anything in 2620:0101:8001::/48 from 2620:4b::/48 (ICMP, 80/tcp, 443/tcp etc) and previous attempts to contact Mozilla via more normal channels about this have not resulted in a resolution.
ryan@ashburn-netops:~$ mtr --report www.mozilla.com
HOST: ashburn-netops Loss% Snt Last Avg Best Wrst StDev
1. ethernet1-5.ashburn-fw.traff 0.0% 10 0.3 0.6 0.2 3.3 1.0
2. fa0-1.ashburn-rtr3.traffiq.c 0.0% 10 0.6 5.7 0.6 51.1 16.0
3. 2600:c08:2002:3::1 0.0% 10 1.1 2.2 0.9 11.7 3.4
4. core3-bbnet2.wdc002.pnap.net 0.0% 10 0.8 17.2 0.7 136.3 42.7
5. 2001:450:2002:161::1 0.0% 10 1.1 0.9 0.8 1.2 0.1
6. ??? 100.0 10 0.0 0.0 0.0 0.0 0.0
ryan@ashburn-netops:~$ mtr --report addons.mozilla.org
HOST: ashburn-netops Loss% Snt Last Avg Best Wrst StDev
1. ethernet1-5.ashburn-fw.traff 0.0% 10 0.2 0.2 0.2 0.3 0.0
2. fa0-1.ashburn-rtr3.traffiq.c 0.0% 10 0.6 18.9 0.6 183.8 57.9
3. 2600:c08:2002:3::1 0.0% 10 4.0 1.6 0.8 4.0 1.2
4. core3-bbnet2.wdc002.pnap.net 0.0% 10 0.9 0.8 0.7 0.9 0.1
5. 2001:450:2002:161::1 0.0% 10 0.8 48.7 0.8 256.9 81.0
6. ??? 100.0 10 0.0 0.0 0.0 0.0 0.0
ryan@ashburn-netops:~$
Shown above is the forward path via Internap->GBLX, and when we use our path via Cogent->Internap we are equally unsuccessful.
I have a hunch about the issue being related to Internap dissolving their Inter-PNAP AS and the return traffic dying at your network edge. Any BGP/routing contact from Mozilla would be greatly appreciated (work hat: rrawdon@traffiq.com)
Ryan