MTU issues s0.wp.com
Hi, Since about a week or so it's become impossible to reach wp.com content over IPv6. IPv4 content does work fine, using the IPv6 literal returns a 404 which is small enough to fit in a smaller 1480 byte MTU. I have another test site that has a clean 1500 byte mtu and I can fetch the s0.wp.com page from there. It looks like tunneled IPv6 users might be in hurt here. Is anyone else experiencing similar issues? My traceroute shows they are employing a CDN for s0.wp.com, so not everyone might be affected. 7 asd2-rou-1022.NL.eurorings.net (2001:680:0:800f::291) 6.460 ms 6.203 ms 6.188 ms 8 asd2-rou-1044.eurorings.net (2001:680::134:222:85:63) 6.447 ms 6.494 ms 6.495 ms 9 adm-b5-link.telia.net (2001:2000:3080:6f::1) 6.818 ms 6.936 ms 6.891 ms 10 ldn-b3-v6.telia.net (2001:2000:3018:5::1) 15.290 ms 27.481 ms 15.380 ms 11 edgecast-ic-147468-ldn-b3.c.telia.net (2001:2000:3080:378::2) 15.116 ms 15.174 ms 15.176 ms 12 2606:2800:234:1922:15a7:17bf:bb7:f09 (2606:2800:234:1922:15a7:17bf:bb7:f09) 15.496 ms 15.327 ms 15.460 ms Kind regards, Seth
On Nov 6, 2012 6:35 AM, "Seth Mos" <seth.mos@dds.nl> wrote:
Hi,
Since about a week or so it's become impossible to reach wp.com content
over IPv6. [snip]
It looks like tunneled IPv6 users might be in hurt here.
Is anyone else experiencing similar issues?
I've definitely had problems from my home network (HE tunnel) recently. I hadn't had time to look into it yet -- too swamped at work. But the above would be consistent with what I've seen. Scott
Is anyone else experiencing similar issues?
Not from here (AS 2116, Norway). No problem getting up the web page, tcpdump shows MSS 1440.
My traceroute shows they are employing a CDN for s0.wp.com, so not everyone might be affected.
7 asd2-rou-1022.NL.eurorings.net (2001:680:0:800f::291) 6.460 ms 6.203 ms 6.188 ms 8 asd2-rou-1044.eurorings.net (2001:680::134:222:85:63) 6.447 ms 6.494 ms 6.495 ms 9 adm-b5-link.telia.net (2001:2000:3080:6f::1) 6.818 ms 6.936 ms 6.891 ms 10 ldn-b3-v6.telia.net (2001:2000:3018:5::1) 15.290 ms 27.481 ms 15.380 ms 11 edgecast-ic-147468-ldn-b3.c.telia.net (2001:2000:3080:378::2) 15.116 ms 15.174 ms 15.176 ms 12 2606:2800:234:1922:15a7:17bf:bb7:f09 (2606:2800:234:1922:15a7:17bf:bb7:f09) 15.496 ms 15.327 ms 15.460 ms
I have a clean 1500 byte path to s0.wp.com through Level3 and Telia: 1 ge0-0-0-10.ar1.skxy.no.catchbone.net (2001:8c0:9602:1::1) 7.937 ms 7.882 ms 10.373 ms 2 ge0-0-2.cr2.osls.as2116.net (2001:8c0:3::71) 9.745 ms 9.540 ms 9.117 ms 3 te3-0-0.br1.osls.as2116.net (2001:8c0:3::292) 10.352 ms 9.548 ms 9.733 ms 4 te-4-1.car1.Oslo1.Level3.net (2001:1900:5:2:1::99) 10.374 ms 9.023 ms 10.206 ms 5 ae-3-6.bar1.Copenhagen1.Level3.net (2001:1900:5:1::49) 18.002 ms 18.597 ms 14.754 ms 6 ae-0-10.bar1.Copenhagen2.Level3.net (2001:1900:5:1::1b6) 15.193 ms 19.215 ms 15.314 ms 7 kbn-b3-link.telia.net (2001:2000:3080:459::1) 20.434 ms 18.480 ms 15.821 ms 8 ldn-b3-v6.telia.net (2001:2000:3018:5::1) 41.915 ms 62.951 ms 39.543 ms 9 edgecast-ic-147468-ldn-b3.c.telia.net (2001:2000:3080:378::2) 40.656 ms 37.063 ms 37.683 ms 10 2606:2800:234:1922:15a7:17bf:bb7:f09 (2606:2800:234:1922:15a7:17bf:bb7:f09) 39.866 ms 39.443 ms 40.827 ms Steinar Haug, AS 2116
On 2012-11-06 13:33, Seth Mos wrote:
Hi,
Since about a week or so it's become impossible to reach wp.com content over IPv6.
IPv4 content does work fine, using the IPv6 literal returns a 404 which is small enough to fit in a smaller 1480 byte MTU.
I have another test site that has a clean 1500 byte mtu and I can fetch the s0.wp.com page from there.
It looks like tunneled IPv6 users might be in hurt here.
tracepath and scapy are the tools of choice here to determine where pMTU messages go missing. Also, it would be very useful to have a source address when reporting these issues as it might affect a lot of other paths too. Greets, Jeroen
Since about a week or so it's become impossible to reach wp.com content over IPv6.
IPv4 content does work fine, using the IPv6 literal returns a 404 which is small enough to fit in a smaller 1480 byte MTU.
I have another test site that has a clean 1500 byte mtu and I can fetch the s0.wp.com page from there.
It looks like tunneled IPv6 users might be in hurt here.
Yes, a middlebox is discarding PTB messages before they reach the webserver: $ scamper -F ipfw -I "tbit -u 'http://s0.wp.com/' 2606:2800:220:1c85:99b:1b56:207e:ea5" tbit from 2001:48d0:101:501:d267:e5ff:fe14:a701 to 2606:2800:220:1c85:99b:1b56:207e:ea5 server-mss 1440, result: pmtud-fail app: http, url: http://s0.wp.com/ [ 0.048] TX SYN 64 seq = 0:0 [ 0.061] RX SYN/ACK 64 seq = 0:1 [ 0.099] TX 60 seq = 1:1 [ 0.148] TX 228 seq = 1:1(168) [ 0.161] RX 60 seq = 1:169 [ 0.162] RX 1500 seq = 1:169(1440) [ 0.162] RX 1500 seq = 1441:169(1440) [ 0.162] RX 1500 seq = 2881:169(1440) [ 0.162] RX 1500 seq = 4321:169(1440) [ 0.162] RX 1500 seq = 5761:169(1440) [ 0.162] RX 914 seq = 7201:169(854) [ 0.198] TX PTB 1280 mtu = 1280 [ 0.248] TX 60 seq = 169:1 [ 3.173] RX 1500 seq = 1:169(1440) [ 3.173] TX PTB 1280 mtu = 1280 [ 6.044] RX FIN 60 seq = 8055:169 [ 6.044] TX 60 seq = 169:1 [ 9.183] RX 1500 seq = 1:169(1440) [ 9.183] TX PTB 1280 mtu = 1280 [ 21.204] RX 1500 seq = 1:169(1440) [ 21.204] TX PTB 1280 mtu = 1280 [ 45.254] RX 1500 seq = 1:169(1440)
On Nov 6, 2012, at 4:33 AM, Seth Mos wrote:
Hi,
Since about a week or so it's become impossible to reach wp.com content over IPv6.
IPv4 content does work fine, using the IPv6 literal returns a 404 which is small enough to fit in a smaller 1480 byte MTU.
I have another test site that has a clean 1500 byte mtu and I can fetch the s0.wp.com page from there.
It looks like tunneled IPv6 users might be in hurt here.
Is anyone else experiencing similar issues?
My traceroute shows they are employing a CDN for s0.wp.com, so not everyone might be affected.
7 asd2-rou-1022.NL.eurorings.net (2001:680:0:800f::291) 6.460 ms 6.203 ms 6.188 ms 8 asd2-rou-1044.eurorings.net (2001:680::134:222:85:63) 6.447 ms 6.494 ms 6.495 ms 9 adm-b5-link.telia.net (2001:2000:3080:6f::1) 6.818 ms 6.936 ms 6.891 ms 10 ldn-b3-v6.telia.net (2001:2000:3018:5::1) 15.290 ms 27.481 ms 15.380 ms 11 edgecast-ic-147468-ldn-b3.c.telia.net (2001:2000:3080:378::2) 15.116 ms 15.174 ms 15.176 ms 12 2606:2800:234:1922:15a7:17bf:bb7:f09 (2606:2800:234:1922:15a7:17bf:bb7:f09) 15.496 ms 15.327 ms 15.460 ms
Kind regards,
Seth
Exact same issue here over HE.net tunnel. I can get errors from the (presumably) front-end proxy, but content stalls forever. I'm seeing this for all WP related requests that go to EdgecastCDN. -- chort
Same here too...i don't know if having a direct peering with Edgecast will solve the issue. -- Tassos Brian Keefer wrote on 8/11/2012 05:08:
On Nov 6, 2012, at 4:33 AM, Seth Mos wrote:
Hi,
Since about a week or so it's become impossible to reach wp.com content over IPv6.
IPv4 content does work fine, using the IPv6 literal returns a 404 which is small enough to fit in a smaller 1480 byte MTU.
I have another test site that has a clean 1500 byte mtu and I can fetch the s0.wp.com page from there.
It looks like tunneled IPv6 users might be in hurt here.
Is anyone else experiencing similar issues?
My traceroute shows they are employing a CDN for s0.wp.com, so not everyone might be affected.
7 asd2-rou-1022.NL.eurorings.net (2001:680:0:800f::291) 6.460 ms 6.203 ms 6.188 ms 8 asd2-rou-1044.eurorings.net (2001:680::134:222:85:63) 6.447 ms 6.494 ms 6.495 ms 9 adm-b5-link.telia.net (2001:2000:3080:6f::1) 6.818 ms 6.936 ms 6.891 ms 10 ldn-b3-v6.telia.net (2001:2000:3018:5::1) 15.290 ms 27.481 ms 15.380 ms 11 edgecast-ic-147468-ldn-b3.c.telia.net (2001:2000:3080:378::2) 15.116 ms 15.174 ms 15.176 ms 12 2606:2800:234:1922:15a7:17bf:bb7:f09 (2606:2800:234:1922:15a7:17bf:bb7:f09) 15.496 ms 15.327 ms 15.460 ms
Kind regards,
Seth
Exact same issue here over HE.net tunnel. I can get errors from the (presumably) front-end proxy, but content stalls forever. I'm seeing this for all WP related requests that go to EdgecastCDN.
-- chort
participants (7)
-
Brian Keefer -
Jeroen Massar -
Matthew Luckie -
Seth Mos -
sthaug＠nethelp.no -
Tassos Chatzithomaoglou -
Timothy Morizot