On 11/8/14 1:02 PM, Frank Bulk wrote:
The Google angle is also being discussed on outages. Initial suspicions are PTB packets not flowing through tunneled connections.
you can also have problems in the other direction e.g. if your tunnel ingress sends a ptb towards a load balanced service it may not arrive. https://tools.ietf.org/html/draft-v6ops-pmtud-ecmp-problem-00 if you're tunneled it does help a lot if your mss reflects the cost of the tunnel you know exists.
Frank
-----Original Message----- From: NANOG [mailto:nanog-bounces@nanog.org] On Behalf Of Pete Carah Sent: Saturday, November 08, 2014 4:56 PM To: nanog@nanog.org Subject: v6 cdn problems
Prefix this - I'm on fios in the Baltimore area, using a HE tunnel terminating in ashburn. (*still* no native v6 on fios :-( Speedtest shows little or no congestion, and didn't change significantly when I reduced mtu by 8. (interestingly, speedtest.net usually reads faster than verizon's internal speedtest, and rarely averages less than my billed speed.)
I've recently had problems (started a few weeks ago with www.att.com, 4-5 days ago with *.google.com) which unfortunately happy eyeballs doesn't help. att.com uses akamai, google uses their own cdn (per dns; I don't know if there are any connections behind the scenes.) This occurs on several google sites, all of which resolve to the same netblocks from here (maps.google.com, www.google.com, maps.gstatic.com, and at least one of the ad servers).
Symptom with akamai is that it connects immediately then data transfer times out. With google, symptom involves both slow connection, and data transfer timing out. I don't know if chrome's happy eyeballs is working since if it was, and absent address caching, I shouldn't see the slow connection.
v6 connections to my hosts in Los Angeles (not on HE address space, but we do peer with them on any2) work fine transferring graphics and large database files both ways, so I'm pretty sure I don't have an mtu problem nor some other fios or HE problem. Just to be sure, I dropped the 1500 to 1492 on the fios link and did the same adjustment to the mtu on my tunnel (becomes 1472). No change on my hosts. att.com appears a little better, though still very slow. Google shows no change at all.
I saw some of the same problem yesterday from Frederick on comcast (only to google, didn't look at att), but couldn't take the time to do traceroutes. If desired, I'm likely to go out there tomorrow and can do that too. (we use a freebsd+pf router there).
Is this a provisioning problem where v6 eyeballs are outstripping cdn provisioning (since win7 and 8 both default to v6)? Or is something else going on. Since this seems to affect more than one cdn, it seems odd.
I run my own resolver locally instead of using verizon's. (and my own (vyatta) router instead of theirs. Actually I'm still using theirs as a bridge to talk to the set-top box (I don't know if Motorola still makes the coax terminal that would bridge it directly...)
Resolve and traceroutes of relevant sites:
[pete@port5 ~]$ host www.att.com www.att.com is an alias for prod-www.zr-att.com.akadns.net. prod-www.zr-att.com.akadns.net is an alias for www.att.com.edgekey.net. www.att.com.edgekey.net is an alias for e2318.dscb.akamaiedge.net. e2318.dscb.akamaiedge.net has address 23.76.217.145 e2318.dscb.akamaiedge.net has IPv6 address 2600:807:320:202:9200::90e e2318.dscb.akamaiedge.net has IPv6 address 2600:807:320:202:8600::90e
Traceroute (v4) to this shows it is in Newark or environs: [pete@port5 ~]$ traceroute e2318.dscb.akamaiedge.net traceroute to e2318.dscb.akamaiedge.net (23.76.217.145), 30 hops max, 60 byte packets 1 rtr.east.altadena.net (192.168.170.1) 2.008 ms 2.450 ms 3.091 ms 2 L300.BLTMMD-VFTTP-64.verizon-gni.net (108.3.150.1) 9.021 ms 9.054 ms 9.045 ms 3 G0-7-4-5.BLTMMD-LCR-21.verizon-gni.net (100.41.195.94) 10.670 ms 10.683 ms 10.677 ms 4 ae4-0.RES-BB-RTR2.verizon-gni.net (130.81.209.230) 9.002 ms ae20-0.RES-BB-RTR1.verizon-gni.net (130.81.151.112) 8.995 ms so-1-1-0-0.RES-BB-RTR1.verizon-gni.net (130.81.199.2) 8.953 ms 5 * * * 6 * * * 7 0.xe-5-0-4.XL3.EWR6.ALTER.NET (140.222.225.73) 51.202 ms 41.102 ms 40.345 ms 8 0.ae1.XL4.EWR6.ALTER.NET (140.222.228.41) 33.065 ms TenGigE0-6-0-3.GW8.EWR6.ALTER.NET (152.63.19.158) 11.550 ms TenGigE0-6-0-6.GW8.EWR6.ALTER.NET (152.63.25.10) 11.659 ms 9 TenGigE0-7-0-1.GW8.EWR6.ALTER.NET (152.63.19.166) 19.854 ms akamai-gw.customer.alter.net (152.179.185.126) 1766.402 ms TenGigE0-7-0-7.GW8.EWR6.ALTER.NET (152.63.25.30) 18.227 ms 10 akamai-gw.customer.alter.net (152.179.185.126) 1747.269 ms a23-76-217-145.deploy.static.akamaitechnologies.com (23.76.217.145) 10.672 ms 11.263 ms
Traceroute6 to it appears to be local (but is hard to tell. Next-to-last hop looks like either a router or load-balancer is overloaded. Same for the v4 traceroute...
[pete@port5 ~]$ traceroute6 www.att.com traceroute to www.att.com (2600:807:320:202:9200::90e), 30 hops max, 80 byte packets 1 rtr.east.altadena.net (2001:470:e160:1::1) 5.182 ms 5.274 ms 5.254 ms 2 altadenamd-1.tunnel.tserv13.ash1.ipv6.he.net (2001:470:7:126::1) 11.452 ms 15.040 ms 18.592 ms 3 ge4-12.core1.ash1.he.net (2001:470:0:90::1) 20.273 ms 20.574 ms 20.567 ms 4 eqx.br6.iad8.verizonbusiness.com (2001:504:0:2::701:1) 20.522 ms 20.232 ms 20.475 ms 5 * * * 6 2600:802:44f::2 (2600:802:44f::2) 1283.113 ms 1296.115 ms 1296.181 ms 7 2600:807:320:200::1743:f397 (2600:807:320:200::1743:f397) 20.181 ms 16.169 ms 14.073 ms
[pete@port5 ~]$ host www.google.com www.google.com has address 74.125.228.16 www.google.com has address 74.125.228.20 www.google.com has address 74.125.228.17 www.google.com has address 74.125.228.19 www.google.com has address 74.125.228.18 www.google.com has IPv6 address 2607:f8b0:4004:800::1012
Traceroute (v4) to this shows something odd, but I don't know where "burl" is for verizon. Also I appear to hit two nodes for the terminal. At least one google node appears to be ashburn (or environs) : [pete@port5 ~]$ traceroute www.google.com traceroute to www.google.com (74.125.228.20), 30 hops max, 60 byte packets 1 rtr.east.altadena.net (192.168.170.1) 2.646 ms 2.816 ms 3.536 ms 2 L300.BLTMMD-VFTTP-64.verizon-gni.net (108.3.150.1) 4.109 ms 4.194 ms 4.186 ms 3 G0-7-4-4.BLTMMD-LCR-22.verizon-gni.net (130.81.170.84) 7.928 ms 8.096 ms 8.088 ms 4 ae20-0.PHIL-BB-RTR1.verizon-gni.net (130.81.151.120) 10.881 ms ae20-0.PHIL-BB-RTR2.verizon-gni.net (130.81.151.124) 11.074 ms so-6-1-0-0.PHIL-BB-RTR2.verizon-gni.net (130.81.199.4) 11.047 ms 5 0.xe-7-0-2.XL2.IAD8.ALTER.NET (152.63.4.93) 14.872 ms 0.xe-3-0-1.XL3.IAD8.ALTER.NET (152.63.3.61) 37.703 ms 12.268 ms 6 0.xe-9-2-0.GW9.IAD8.ALTER.NET (152.63.36.30) 12.866 ms 0.xe-11-2-1.GW9.IAD8.ALTER.NET (152.63.42.2) 14.442 ms 0.xe-9-2-0.GW9.IAD8.ALTER.NET (152.63.36.30) 11.918 ms 7 * 0.xe-10-1-1.GW9.IAD8.ALTER.NET (152.63.35.113) 16.901 ms pool-96-236-104-66.burl.east.verizon.net (96.236.104.66) 136.110 ms 8 pool-96-236-104-66.burl.east.verizon.net (96.236.104.66) 137.977 ms 216.239.46.248 (216.239.46.248) 13.875 ms pool-96-236-104-66.burl.east.verizon.net (96.236.104.66) 134.602 ms 9 216.239.46.248 (216.239.46.248) 15.918 ms 10.708 ms 10.162 ms 10 72.14.238.173 (72.14.238.173) 11.347 ms 12.111 ms iad23s05-in-f20.1e100.net (74.125.228.20) 12.769 ms
Corresponding traceroute6 (shows lack of reverse on most hits...): [pete@port5 ~]$ traceroute6 www.google.com traceroute to www.google.com (2607:f8b0:4004:800::1011), 30 hops max, 80 byte packets 1 rtr.east.altadena.net (2001:470:e160:1::1) 1.640 ms 1.811 ms 1.801 ms 2 altadenamd-1.tunnel.tserv13.ash1.ipv6.he.net (2001:470:7:126::1) 11.977 ms 15.279 ms 19.265 ms 3 ge4-12.core1.ash1.he.net (2001:470:0:90::1) 19.779 ms 20.776 ms 22.303 ms 4 2001:4860:1:1:0:1b1b:0:d (2001:4860:1:1:0:1b1b:0:d) 22.267 ms 22.514 ms 22.507 ms 5 2001:4860::1:0:9ff (2001:4860::1:0:9ff) 22.508 ms 22.471 ms 22.455 ms 6 2001:4860:0:1::551 (2001:4860:0:1::551) 22.467 ms 19.139 ms 19.116 ms 7 2607:f8b0:8000:18::c (2607:f8b0:8000:18::c) 19.054 ms 2607:f8b0:8000:18::f (2607:f8b0:8000:18::f) 7.716 ms 2607:f8b0:4004:800::1b (2607:f8b0:4004:800::1b) 8.379 ms
Again shows multiple terminals for the given address.
Ping works fine to all of the addresses, both v4 and v6, and the att one always connects immediately. The google one doesn't always.
When I disable the HE tunnel, (and restart the browser - apparently happy-eyeballs caches), everything works just fine, so the problem does appear to relate to v6.
For reference, I mostly use chrome in linux. My daughter sees the same problem with google, mostly using chrome in win 7. I see the problem with firefox (in linux) also (to both sites).
-- Pete