Looks to be fixed as of ~ 14:55 Eastern.     ---Mike On 6/24/2022 1:49 PM, mike tancsa wrote:

We noticed random traffic originating from AS577 stopped getting to our ASN via Cogent in Montreal at around 00:24 this morning. Based on the pattern I am guessing a broken next hop on one leg of a larger link ?  e.g. IP traffic leaving AS577 towards IP addresses in one of my /19s will 100% work for certain IPs and 100% fail for others all within that same /19.

e.g. from 142.112.93.72 (an IP originating in AS577) to one of the IPs below in my 64.7.128.0/19

64.7.134.1 100% fail 64.7.134.2 100% pass 64.7.134.3 fail 64.7.134.4 fail 64.7.134.5 fail 64.7.134.6 fail 64.7.134.7 100% pass 64.7.134.8 100% fail 64.7.134.9 fail 64.7.134.10 pass

Its just packets towards my ASN that are failing. Packets TO  577 via 174 all work fine.

Traceroutes good and bad all look like this

% traceroute -s 142.112.93.72 -q1 -I 64.7.134.2 traceroute to 64.7.134.2 (64.7.134.2) from 142.112.93.72, 64 hops max, 48 byte packets  1  lns5-ottawa23_lo0.net.bell.ca (64.230.11.188)  10.507 ms  2  64.230.98.68 (64.230.98.68)  17.539 ms  3  tcore4-montreal02_1-9-0-0.net.bell.ca (64.230.79.127) 18.150 ms  4  cr02-mtrlpq02ho6_bundle-ether1.net.bell.ca (142.124.127.251) 13.787 ms  5  bx1-montrealgz_et-0-0-5.net.bell.ca (64.230.26.135)  12.237 ms * 6  **  7  be2089.ccr21.ymq01.atlas.cogentco.com (154.54.45.113) 13.337 ms  8  be3259.ccr31.yyz02.atlas.cogentco.com (154.54.41.205) 17.969 ms  9  sentex.demarc.cogentco.com (38.104.158.78)  17.126 ms 10  agas-core1-em0.sentex.ca (67.43.129.251)  39.960 ms 11  agas-lns1c-c.sentex.ca (64.7.129.19)  32.171 ms 12  orbiting.anysphere.com (64.7.134.2)  49.336 ms

% traceroute -s 142.112.93.72 -q1 -I 64.7.134.1 traceroute to 64.7.134.1 (64.7.134.1) from 142.112.93.72, 64 hops max, 48 byte packets  1  lns5-ottawa23_lo0.net.bell.ca (64.230.11.188)  10.229 ms  2  64.230.98.66 (64.230.98.66)  13.346 ms  3  tcore3-montreal02_hu2-4-0-2.net.bell.ca (64.230.78.252) 12.660 ms  4  cr01-mtrlpq02ho5_bundle-ether1.net.bell.ca (142.124.127.233) 12.423 ms  5  bx1-montrealgz_et-0-0-1.net.bell.ca (64.230.26.133)  12.225 ms *6  **  7  *  8  *  9  * 10  * 11  *

Not sure if hop 6 is a Bell device or Cogent device. I have a ticket open with Cogent, but they dont see any issues in their network. I am not a direct customer of Bell, so I cant open a ticket with them. Was hoping someone from AS577 would see this and take a look.

    ---Mike