The congestion might be on the reverse path. Can you get a trace route in the opposite direction? Thanks. On Fri, Feb 4, 2022, 7:55 AM Lukas Tribus via Outages <outages@outages.org> wrote:
Dear list,
There is major congestion for 8 - 10 hours every day on the GTT network from Frankfurt, Germany towards Milan, Italy.
Before noon (localtime, that would be 1200~1300Z) things are looking fine but in the afternoon, packet-loss and latency increase steadily (peaking in the evening). We are talking packet-loss in excess of 10% and ten times the expected latency:
lukas@htznr2:~$ mtr 62.10.128.1 -wrs1000 -c1000 Start: 2022-02-03T21:33:28+0100
HOST: htznr2 Loss% Snt Last Avg Best Wrst StDev 1.|-- _gateway 0.0% 1000 3.1 4.9 2.3 18.0 1.3 2.|-- 10114.your-cloud.host 0.0% 1000 0.2 0.3 0.2 4.0 0.2 3.|-- ??? 100.0 1000 0.0 0.0 0.0 0.0 0.0 4.|-- 85-10-250-153.clients.your-server.de 0.0% 1000 1.3 4.8 0.8 98.6 11.8 5.|-- spine12.cloud1.nbg1.hetzner.com 0.0% 1000 1.1 4.8 0.8 66.8 11.4 6.|-- 213-239-239-121.clients.your-server.de 0.0% 1000 3.0 2.3 0.5 43.4 4.1 7.|-- core1.fra.hetzner.com 0.0% 1000 3.6 5.7 3.5 65.2 5.0 8.|-- ae18.cr6-fra2.ip4.gtt.net 0.0% 1000 4.8 5.8 3.6 116.7 6.7 9.|-- et-5-1-0.cr0-mil2.ip4.gtt.net 11.1% 1000 114.0 112.3 63.5 172.7 13.4 10.|-- tiscali.ip4.gtt.net 11.5% 1000 111.5 113.4 64.3 148.8 13.2 11.|-- static-94-32-126-81.clienti.tiscali.it 10.6% 1000 121.7 126.4 79.8 162.9 13.7 12.|-- static-94-32-135-162.clienti.tiscali.it 11.2% 1000 119.1 126.8 80.9 176.8 13.9 13.|-- static-94-32-135-182.clienti.tiscali.it 11.3% 1000 119.0 127.6 79.5 171.2 14.2 14.|-- static-213-205-54-210.clienti.tiscali.it 78.7% 1000 130.1 125.3 73.8 228.1 16.2 15.|-- ??? 100.0 1000 0.0 0.0 0.0 0.0 0.0 lukas@htznr2:~$
2022-02-01T18:10:07Z https://pastebin.com/raw/MSvuSuR0
2022-02-02T17:39:44Z https://pastebin.com/raw/zWD8GHGa
2022-02-03T20:33:28Z (as above) https://pastebin.com/raw/DHWDyi1g
2022-02-04T13:11:51Z https://pastebin.com/raw/qhrWZBQX
GTT NOC has been advised Feb 1st, 18:000Z, but apparently they always verify network issues in the morning, which is also when those links are uncongested, so at this point there is no confirmation from them. I'm assuming the network teams are aware of it anyway, but we don't know for sure. If you are using GTT for transit in Europe and traffic to Italy matters to your customers, you probably want to reroute (for example: reducing loc-pref based on GTT's BGP community 3257:53900 for prefixes learned in Italy).
cheers, lukas _______________________________________________ Outages mailing list Outages@outages.org https://puck.nether.net/mailman/listinfo/outages