November 2014 - Test - lists.nanog.org

Contact @ harvard.edu?
by Staudinger, Malcolm 10 Nov '14

10 Nov '14

If anyone from Harvard IT (preferably network/netsec, but I'll take anyone at this point) is on this list, please drop me a line regarding a DoS from your network. I haven't had any luck getting past your student help desk/ticket system. Malcolm Staudinger Information Security Analyst II | EIS EarthLink<http://www.earthlink.com/> E: mstaudinger(a)elnk.com M: 360-936-5957 [http://www.earthlinkmarketingservices.com/email_logo_sm.png]

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Re: I am about to inherit 26 miles of dark fiber. What do I do with it?
by Scott Weeks 10 Nov '14

10 Nov '14

--- fkittred(a)gwi.net wrote: From: Fletcher Kittredge <fkittred(a)gwi.net> The below is a really sad story. Condolences on the coming trainwreck. I hope you get someone on staff or on consult that understands outside plant architecture, because it is much more important and complex topic than you seem to realize. ----------------------------------------- Help guide and build knowledge instead of publicly beat down. scott

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Fwd: [v6ops] IPv6 MTU Flow-label.... (related to draft-v6ops-pmtud-ecmp-problem-01)
by Jeroen Massar 10 Nov '14

10 Nov '14

Forwarding this so that everybody can comment on this nasty proposal ;) Forcing replies to v6ops(a)ietf.org where they likely should be taking place as that is where recently the mentioned draft was accepted as a WG item. Greets, Jeroen -------- Forwarded Message -------- Subject: [v6ops] IPv6 MTU Flow-label.... (related to draft-v6ops-pmtud-ecmp-problem-01) Date: Mon, 10 Nov 2014 11:31:52 +0100 From: Jeroen Massar <jeroen(a)massar.ch> Organization: Massar To: ipv6(a)ietf.org, v6ops(a)ietf.org Hola folks (and folks in BCC ;), With the recent Google and Akamai outages (latter still ongoing afaik), it came to light that the cause is likely the model and problem described here: https://tools.ietf.org/html/draft-v6ops-pmtud-ecmp-problem-01 which previously was: https://tools.ietf.org/html/draft-v6ops-jaeggli-pmtud-ecmp-problem-01 Or shortly described: terminating an IP address at different hosts and having the balancer box not knowing where to deliver the ICMP PTBs that get send for large packets. One of the suggestions there is to lower the MSS for every connection by forcing it (either on the loadbalancer or on the final host) to a value that "works everywhere": the one for an MTU of 1280. MSS only applies to TCP, and people like Google are coming out with QUIC and other schemes. As we really do not want an Internet at an MTU of 1280, why don't we indicate in the packet what the MTU is when it is diverting from the norm? What if we instead let a router that sources a packet from a link or is going to transmit a packet over a link < 1500 indicate with that packet that that packet came from/is going to is a link with a MTU < 1500. We can't use an additional extension header, as adding anything would mean we might hit the MTU of the packet and we have other issues. As our least-known-used field is the FlowLabel field, we could abuse that and have enough bits there to stuff our data. What if we define that when the first 4 bits are set to 0xF (all one) that the rest (16bits) defines the MTU of the link (MTU 0 - 65k)? (We could even use a 'base of 1280' and thus 0xf0000 = 1280 MTU, but possibly it is better to state "value of < 0xf0500 is invalid") Thus allowing when the first 4 bits are not set to all-1 that the flowlabel field is a "normal flowlabel" field ala RFC6437. We could even state "Only set this MTU option when the FlowLabel field == 0" to avoid incompatibility (though I do not expect any as I rarely see packets with the field non-0...) Thus given a network like: [H1] 2001:db8:1500::1/64 | mtu = 1500 2001:db8:1500::a/64 [RA] 2001:db8:1501::a/64 | mtu = 1500 2001:db8:1501::b/64 [RB] 2001:db8:1480::b/64 | mtu = 1480 2001:db8:1480::c/64 [RC] 2001:db8:1280::c/64 | mtu = 1280 2001:db8:1280::d/64 [RD] 2001:db8:9000::d/64 | mtu = 9000 2001:db8:9000::2/64 [H2] RA receives packet, src+dst interface are MTU=1500, thus does nothing RB receives packet, src = 1500, dst = 1480, thus sets FL = 0xf05c8 RC receives packet, src = 1480, dst = 1280, thus sets FL = 0xf0500 RD receives packet, src = 1280, dst = 9000, thus sets FL = 0xf0500 (again, just set is quicker than checking) Now even if H2 is a loadbalancer, if the flow is just forwarded (without TTL change btw...) the destination receives it correctly. The disadvantage is of course that you lose the ability to balance based on the FlowLabel, but if we go with "only change when not 0 then there was one anyway. Also you got src+dst which is 256bits, which should be pretty good already and optionally next-header + the contents of the header if you want that. Note that as we have no checksum in IPv6, there is little overhead to do this kind of forwarding, HopLimit already needs updating, this is just another field to update. In another model from the above, we could even just let every hop set the known lowest MTU. In that case, H1 would set 0xf05dc in the packet, and then it gets lowered automatically. Which would also mean that a pure 9000 path would nicely work suddenly as everybody knows that 9000 will fit :) Greets, Jeroen _______________________________________________ v6ops mailing list v6ops(a)ietf.org https://www.ietf.org/mailman/listinfo/v6ops

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v6 cdn problems
by Pete Carah 10 Nov '14

10 Nov '14

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

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Re: I am about to inherit 26 miles of dark fiber
by Scott Weeks 10 Nov '14

10 Nov '14

:: Ah, the famous good-will of NANOG. But you got more of the good than the other. :: I knew I would get some interesting responses. And you got more of that than non-interesting... :-) scott

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Re: I am about to inherit 26 miles of dark fiber
by Lorell Hathcock 09 Nov '14

09 Nov '14

Ah, the famous good-will of NANOG. I knew I would get some interesting responses. I was part of the Field Ops group of Enron Broadband years ago. We deployed DWDM extensively. Admittedly it has been a while. This 26 miles of dark fiber is deployed by a municipality in and around their fair city. Part of a deal with this new firm is that the firm will use the aforementioned six strands. So the fiber is deployed throughout this city that has been largely under-serviced. By lack of resources, the city could not deploy services to businesses/enterprises. So as I ponder the opportunity, I seek to tap the creative juices of NANOG. Thanks, Lorell Hathcock

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FW: M-Lab-Related PCAPs
by Livingood, Jason 09 Nov '14

09 Nov '14

FYI to this list since I suspect few of you are on the M-Lab Discuss list. Srikanth from ICSI has kindly taken on consolidating some PCAPs. If anyone wishes to send any to him, he is at srknth.s(a)gmail.com<mailto:srknth.s@gmail.com>. JL On 11/6/14, 7:24 PM, "Srikanth S" <srknth.s(a)gmail.com<mailto:srknth.s@gmail.com>> wrote: So it looks as though marking is not done for all MLab traffic. Also, some web traffic (to CNN) is marked at a lower priority than streaming (Netflix), which is strange as web traffic is likely more sensitive to degradation than streaming (?). Here are the traces: http://www1.icsi.berkeley.edu/~srikanth/pcaps/google.pcap http://www1.icsi.berkeley.edu/~srikanth/pcaps/youtube-image.pcap http://www1.icsi.berkeley.edu/~srikanth/pcaps/cnn.pcap http://www1.icsi.berkeley.edu/~srikanth/pcaps/netflix-streaming.pcap On Tuesday, November 4, 2014 1:29:16 PM UTC-8, Jason Livingood wrote: Another follow-up. Someone emailed me a PCAP off-list from an enterprise type of customer. Their PCAP was somewhat incomplete (so I still need more) but they noticed that some traffic at the next priority down from 0x48 at 0x28 (priority). And some other traffic was marked with the next priority down again at 0x00 (routine). So it appears there are three DSCP / ToS markings in use rather than just two (0x00, 0x28, 0x48). So safe to say more research is needed here – anyone collecting PCAPs should IMHO continue. :-) Jason

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Re: Reporting DDOS reflection attacks
by Larry Sheldon 09 Nov '14

09 Nov '14

On 11/9/2014 13:40, Doug Barton wrote: > On 11/8/14 6:33 PM, Roland Dobbins wrote: >> this is incorrect and harmful, and should be removed: >> >> iii. Consider dropping any DNS reply packets which are larger >> than 512 Bytes – these are commonly found in DNS DoS Amplification >> attacks. >> >> This *breaks the Internet*. Don't do it. > > +1 > The whole thing> Really? -- The unique Characteristics of System Administrators: The fact that they are infallible; and, The fact that they learn from their mistakes. Quis custodiet ipsos custodes

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Reporting DDOS reflection attacks
by srn.nanog＠prgmr.com 09 Nov '14

09 Nov '14

Like most small providers, we occasionally get hit by DoS attacks. We got hammered by an SSDP reflection attack (udp port 1900) last week. We took a 27 second log and from there extracted about 160k unique IPs. It is really difficult to find abuse emails for 160k IPs. We know about abuse.net but abuse.net requires hostnames, not IPs for lookups and not all IP addresses have valid DNS entries. The only other way we know of to report problems is to grab the abuse email addresses is whois. However, whois is not structured and is not set up to deal with this number of requests - even caching whois data based on subnets will result in many thousands of lookups. Long term it seems like structured data and some kind of authentication would be ideal for reporting attacks. But right now how should we be doing it?

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DDOS, IDS, RTBH, and Rate limiting
by Eric C. Miller 09 Nov '14

09 Nov '14

Today, we experienced (3) separate DDoS attacks from Eastern Asia, all generating > 2Gbps towards a single IP address in our network. All 3 attacks targeted different IP addresses with dst UDP 19, and the attacks lasted for about 5 minutes and stopped as fast as they started. Does anyone have any suggestions for mitigating these type of attacks? A couple of things that we've done already... We set up BGP communities with our upstreams, and tested that RTBH can be set and it does work. However, by the time that we are able to trigger the black hole, the attack is almost always over. For now, we've blocked UDP 19 incoming at our edge, so that if future, similar attacks occur, it doesn't affect our internal links. What I think that I need is an IDS that can watch our edge traffic and automatically trigger a block hole advertisement for any internal IP beginning to receive > 100Mbps of traffic. A few searches are initially coming up dry... Eric Miller, CCNP Network Engineering Consultant (407) 257-5115

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