At about 3:30PM central time today we started seeing ICMP packet loss going into Level3 networks, we believe it is likely some sort of Level3 filtering of some sort. Two traces below from the same origin to the same destination at the same time, one is ICMP and one is UDP. It is not just traceroute ICMP packets, we cannot ping our own equipment when it takes a Level3 path. Other UDP/TCP traffic so far seems unaffected. Is anyone else seeing this? This appears to be a Chicago-area connection. Using ICMP to trace to: 204.11.209.66 Tracing to host 204.11.209.66 traceroute to 204.11.209.66 (204.11.209.66), 30 hops max, 60 byte packets 1 216.17.34.1 (216.17.34.1) [as10242/AS10242] 0.558 ms 0.554 ms 0.552 ms 2 v103.usi-cr02-mpls.usinternet.com (216.17.36.25) [as10242/AS10242] 1.094 ms 1.199 ms 1.555 ms 3 10gigabitethernet2-6.core1.msp1.he.net (216.66.73.173) [AS6939] 1.203 ms 1.530 ms 1.533 ms 4 100gigabitethernet7-1.core1.chi1.he.net (184.105.223.177) [AS46841] 9.076 ms 9.084 ms 9.154 ms 5 chi-bb1-link.telia.net (213.248.104.213) [AS1299] 9.155 ms 9.163 ms 9.163 ms 6 * * * 7 * * * 8 * * * 9 * * * 10 * * * 11 * * * 12 * * * 13 * * * 14 * * * 15 * * * Using UDP to trace to: 204.11.209.66 Tracing to host 204.11.209.66 traceroute to 204.11.209.66 (204.11.209.66), 30 hops max, 60 byte packets 1 216.17.34.1 (216.17.34.1) [as10242/AS10242] 0.438 ms 0.480 ms 0.495 ms 2 v103.usi-cr02-mpls.usinternet.com (216.17.36.25) [as10242/AS10242] 1.106 ms 1.166 ms 1.235 ms 3 10gigabitethernet2-6.core1.msp1.he.net (216.66.73.173) [AS6939] 4.447 ms 4.445 ms 4.440 ms 4 100gigabitethernet7-1.core1.chi1.he.net (184.105.223.177) [AS46841] 12.821 ms 12.898 ms 12.893 ms 5 chi-bb1-link.telia.net (213.248.104.213) [AS1299] 9.056 ms 9.052 ms 9.054 ms 6 level3-ic-300135-chi-bb1.c.telia.net (213.248.87.238) [AS1299] 23.943 ms 24.000 ms 18.147 ms 7 ae-32-52.ebr2.Chicago1.Level3.net (4.69.138.62) [AS3356] 20.890 ms 18.162 ms 18.189 ms 8 ae-5-5.ebr2.Chicago2.Level3.net (4.69.140.194) [AS3356] 20.993 ms 20.982 ms 22.160 ms 9 ae-22-52.car2.Chicago2.Level3.net (4.69.138.165) [AS3356] 18.164 ms 22.165 ms 18.231 ms 10 RED-ANVIL-L.car2.Chicago2.Level3.net (4.30.14.162) [AS3356] 44.853 ms 44.822 ms 44.810 ms 11 ge-1-0-1-0.cr1.noc.ip.redanvil.net (204.15.100.173) [AS33693] 19.849 ms 19.888 ms 19.797 ms