Hello Nico / everybody

Yesterday, I was contacted by Silvia (and others) about that task. I was then not registered with that list.

Let me introduce me shortly. My name is Urs Mueller. I am working together with my colleague Hans-Peter at SBB in the IT department. We are the stack owners of network & network security on behalf of the IT department. Our network is built and operated by our colleagues from SBB Telecom.

IPv6 is a goal we tried to reach since several years, at least since I attended an IPv6 congress in Hannover many years ago.

We were struggling with convincing the management to fund projects until last year. The current solution is more or less a workaround and this year, we are trying to achieve a direct connection to our webservers.

Currently, there are seeing around 2 Mbit/s incoming and 20 Mbit/s outgoing on IPv6. This is approx. 20% of the total traffic, we are actually handling for our webserver through regular http/s from browsers.

This year, we will give more effort on the subject. But our network is quite complex and grown over the years. So there is no way to "just put a box in between and some cables" ;-)

If you Nico, would like to contact me about your thesis, feel free. Perhaps we can arrange something.

Regards, Urs

-----Ursprüngliche Nachricht----- Von: swinog-bounces@lists.swinog.ch swinog-bounces@lists.swinog.ch Im Auftrag von Nico Schottelius Gesendet: Dienstag, 12. März 2019 15:55 An: Silvia Hagen silvia.hagen@sunny.ch Cc: Nico Schottelius nico-swinog-2@schottelius.org; swinog@lists.swinog.ch Betreff: Re: [swinog] SBB.ch / IPv6 MTU / fragmentation problem

Hey Silvia,

thanks a lot for the insight! I did not expect this answer when asking this morning.

I am currently doing my master thesis [0] about IPv6 in fully programmable P4 switches (my hardware platform will be Barefoot Tofino in the end) - I assume this might be rather interesting for SBB, as it potentially can solve all problems [tm] in the network. Also I hear the 6.5 TBit/s switches are not that crazy expensive anymore.

If you could get me in touch with the right people at SBB, this would be very interesting to talk about their network.

Best,

Nico

[0] https://gitlab.ethz.ch/nicosc/master-thesis

Silvia Hagen silvia.hagen@sunny.ch writes:

Hi guys

Here's some info from SBB (I was working with them and just spoke with them today).

. They are aware of the problem. . The problem only happens when someone uses smaller packet sizes (often when using some tunnelling techniques). . Currently the webserver is in an IPv4 zone, the Internet router is a Cisco box which does 64 Translation. The packets go through an F5 LB to reach the webserver. . When the packets go out and the Cisco box asks for fragmention, it sends the ICMP packet to the webserver. The F5 box has a bug, something with the checksum goes wrong and the F5 discards the ICMP packet. . They have had a neverending incident with F5 and F5 does not seem to be able to fix that. SBB has given up on this incident.

The plan: . SBB is currently enabling IPv6 on the routing layer, plan to be accomplished by summer 2019. . Next step on the plan is to enable v6 out to the datacenter, with priority on the webserver zone. So with that the problems should go away.

SBB was attending the last swinog event in Switzerland. They will also come again and they offered to have a talk if desired. I can connect to the right person if you are interested.

Thanks, Silvia

-----Ursprüngliche Nachricht----- Von: swinog-bounces@lists.swinog.ch [mailto:swinog-bounces@lists.swinog.ch] Im Auftrag von Nico Schottelius Gesendet: Dienstag, 12. März 2019 10:33 An: swinog@lists.swinog.ch Betreff: [swinog] SBB.ch / IPv6 MTU / fragmentation problem

Good morning,

is anyone from sbb.ch reading here?

https://sbb.ch does not load on IPv6 for us. It seems that packets > 1420 bytes are dropped inside the SBB network,

Local PMTU / fragmentation seems to work, my local outgoing MTU is 1420. MTR below.

Best,

Nico

[10:23] line:~% mtr -w -c1 -s 1500 sbb.ch Start: 2019-03-12T10:24:17+0100 HOST: line Loss% Snt Last Avg Best Wrst StDev 1.|-- 2a0a:e5c1:111:111::42 0.0% 1 11.2 11.2 11.2 11.2 0.0 2.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 3.|-- 2a0a:e5c0:2:12::7 0.0% 1 69.8 69.8 69.8 69.8 0.0 4.|-- 2a0a:e5c0:1:1::9 0.0% 1 74.3 74.3 74.3 74.3 0.0 5.|-- 2001:1620:20e6::1 0.0% 1 69.4 69.4 69.4 69.4 0.0 6.|-- r1zrh2.core.init7.net 0.0% 1 69.1 69.1 69.1 69.1 0.0 7.|-- r1olt2.core.init7.net 0.0% 1 58.0 58.0 58.0 58.0 0.0 8.|-- r1brn1.core.init7.net 0.0% 1 62.8 62.8 62.8 62.8 0.0 9.|-- r2brn1.core.init7.net 0.0% 1 65.4 65.4 65.4 65.4 0.0 10.|-- r1epe1.core.init7.net 0.0% 1 75.2 75.2 75.2 75.2 0.0 11.|-- r1qls1.core.init7.net 0.0% 1 78.4 78.4 78.4 78.4 0.0 12.|-- r1gva3.core.init7.net 0.0% 1 81.0 81.0 81.0 81.0 0.0 13.|-- gw-sunrise.init7.net 0.0% 1 64.4 64.4 64.4 64.4 0.0 14.|-- 2001:1700:1:7:120::2 0.0% 1 84.4 84.4 84.4 84.4 0.0 15.|-- 2001:1700:4d00:2::2 0.0% 1 81.3 81.3 81.3 81.3 0.0 16.|-- 2a00:4bc0:ffff:ff00::1d 0.0% 1 67.0 67.0 67.0 67.0 0.0 17.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 [10:24] line:~% mtr -w -c1 -s 1400 sbb.ch Start: 2019-03-12T10:24:35+0100 HOST: line Loss% Snt Last Avg Best Wrst StDev 1.|-- 2a0a:e5c1:111:111::42 0.0% 1 3.2 3.2 3.2 3.2 0.0 2.|-- 2a0a:e5c1:100::1 0.0% 1 69.0 69.0 69.0 69.0 0.0 3.|-- 2a0a:e5c0:2:12::7 0.0% 1 74.7 74.7 74.7 74.7 0.0 4.|-- 2a0a:e5c0:1:1::9 0.0% 1 69.9 69.9 69.9 69.9 0.0 5.|-- 2001:1620:20e6::1 0.0% 1 60.5 60.5 60.5 60.5 0.0 6.|-- r1zrh2.core.init7.net 0.0% 1 75.3 75.3 75.3 75.3 0.0 7.|-- r1olt2.core.init7.net 0.0% 1 70.7 70.7 70.7 70.7 0.0 8.|-- r1brn1.core.init7.net 0.0% 1 69.1 69.1 69.1 69.1 0.0 9.|-- r2brn1.core.init7.net 0.0% 1 54.6 54.6 54.6 54.6 0.0 10.|-- r1epe1.core.init7.net 0.0% 1 75.9 75.9 75.9 75.9 0.0 11.|-- r1qls1.core.init7.net 0.0% 1 78.8 78.8 78.8 78.8 0.0 12.|-- r1gva3.core.init7.net 0.0% 1 79.8 79.8 79.8 79.8 0.0 13.|-- gw-sunrise.init7.net 0.0% 1 69.9 69.9 69.9 69.9 0.0 14.|-- 2001:1700:1:7:120::2 0.0% 1 77.5 77.5 77.5 77.5 0.0 15.|-- 2001:1700:4d00:2::2 0.0% 1 59.3 59.3 59.3 59.3 0.0 16.|-- 2a00:4bc0:ffff:ff00::1d 0.0% 1 70.1 70.1 70.1 70.1 0.0 17.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 18.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 19.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 20.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 21.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 22.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 23.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 24.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 25.|-- 2a00:4bc0:ffff:ffff::c296:f58e 0.0% 1 58.3 58.3 58.3 58.3 0.0 [10:24] line:~%

[10:25] line:~% mtr -w -c1 -s 1420 sbb.ch Start: 2019-03-12T10:25:44+0100 HOST: line Loss% Snt Last Avg Best Wrst StDev 1.|-- 2a0a:e5c1:111:111::42 0.0% 1 16.3 16.3 16.3 16.3 0.0 2.|-- 2a0a:e5c1:100::1 0.0% 1 77.0 77.0 77.0 77.0 0.0 3.|-- 2a0a:e5c0:2:12::7 0.0% 1 67.0 67.0 67.0 67.0 0.0 4.|-- 2a0a:e5c0:1:1::9 0.0% 1 66.7 66.7 66.7 66.7 0.0 5.|-- 2001:1620:20e6::1 0.0% 1 78.8 78.8 78.8 78.8 0.0 6.|-- r1zrh2.core.init7.net 0.0% 1 64.5 64.5 64.5 64.5 0.0 7.|-- r1olt2.core.init7.net 0.0% 1 68.3 68.3 68.3 68.3 0.0 8.|-- r1brn1.core.init7.net 0.0% 1 74.9 74.9 74.9 74.9 0.0 9.|-- r2brn1.core.init7.net 0.0% 1 73.6 73.6 73.6 73.6 0.0 10.|-- r1epe1.core.init7.net 0.0% 1 62.2 62.2 62.2 62.2 0.0 11.|-- r1qls1.core.init7.net 0.0% 1 74.3 74.3 74.3 74.3 0.0 12.|-- r1gva3.core.init7.net 0.0% 1 63.6 63.6 63.6 63.6 0.0 13.|-- gw-sunrise.init7.net 0.0% 1 69.1 69.1 69.1 69.1 0.0 14.|-- 2001:1700:1:7:120::2 0.0% 1 77.4 77.4 77.4 77.4 0.0 15.|-- 2001:1700:4d00:2::2 0.0% 1 78.8 78.8 78.8 78.8 0.0 16.|-- 2a00:4bc0:ffff:ff00::1d 0.0% 1 75.7 75.7 75.7 75.7 0.0 17.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 18.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 19.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 20.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 21.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 22.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 23.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 24.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 25.|-- 2a00:4bc0:ffff:ffff::c296:f58e 0.0% 1 83.8 83.8 83.8 83.8 0.0 [10:25] line:~% mtr -w -c1 -s 1430 sbb.ch Start: 2019-03-12T10:25:55+0100 HOST: line Loss% Snt Last Avg Best Wrst StDev 1.|-- 2a0a:e5c1:111:111::42 0.0% 1 7.3 7.3 7.3 7.3 0.0 2.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 3.|-- 2a0a:e5c0:2:12::7 0.0% 1 60.4 60.4 60.4 60.4 0.0 4.|-- 2a0a:e5c0:1:1::9 0.0% 1 61.9 61.9 61.9 61.9 0.0 5.|-- 2001:1620:20e6::1 0.0% 1 72.2 72.2 72.2 72.2 0.0 6.|-- r1zrh2.core.init7.net 0.0% 1 65.2 65.2 65.2 65.2 0.0 7.|-- r1olt2.core.init7.net 0.0% 1 64.9 64.9 64.9 64.9 0.0 8.|-- r1brn1.core.init7.net 0.0% 1 64.9 64.9 64.9 64.9 0.0 9.|-- r2brn1.core.init7.net 0.0% 1 71.7 71.7 71.7 71.7 0.0 10.|-- r1epe1.core.init7.net 0.0% 1 64.4 64.4 64.4 64.4 0.0 11.|-- r1qls1.core.init7.net 0.0% 1 63.2 63.2 63.2 63.2 0.0 12.|-- r1gva3.core.init7.net 0.0% 1 77.9 77.9 77.9 77.9 0.0 13.|-- gw-sunrise.init7.net 0.0% 1 64.5 64.5 64.5 64.5 0.0 14.|-- 2001:1700:1:7:120::2 0.0% 1 63.5 63.5 63.5 63.5 0.0 15.|-- 2001:1700:4d00:2::2 0.0% 1 81.7 81.7 81.7 81.7 0.0 16.|-- 2a00:4bc0:ffff:ff00::1d 0.0% 1 74.4 74.4 74.4 74.4 0.0 17.|-- ??? 100.0 1 0.0 0.0 0.0 0.0 0.0 [10:26] line:~%

icmp6, frag works locally:

10:29:44.919328 IP6 2a0a:e5c1:111:111:3185:e802:6548:658c > 2a00:4bc0:ffff:ffff::c296:f58e: frag (0|1368) ICMP6, echo request, seq 33000, length 1368 10:29:44.919368 IP6 2a0a:e5c1:111:111:3185:e802:6548:658c > 2a00:4bc0:ffff:ffff::c296:f58e: frag (1368|92)

-- Your Swiss, Open Source and IPv6 Virtual Machine. Now on www.datacenterlight.ch.

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