Hi Geert, These PMTU issues are a bit strange, as, our entire backbone is based on IPv6 native transits and peers, and we are also delivering two dual-stacked uplinks to the RIPE Meeting, with native IPv6 connectivity. I am available to investigate this further, also with RIPE OPS. Feel free to "ping" me at anytime. regards, --- Nuno Vieira nfsi telecom, lda. [Email] nuno.vieira@nfsi.pt [Phone] +351 21 114 2315 [Phone] +351 21 142 2300 [Mobile] +351 91 925 5561 [Fax] +351 21 114 2301 [Web] http://www.nfsi.pt/ ----- "Geert Jan de Groot" <GeertJan.deGroot@xs4all.nl> wrote:

Hi,

By monitoring the stream from Lisbon, I can tell the RIPE meeting is going well and lots of resolution is made towards deployment of technologies like IPv6, DNSSEC and others. It's good to see many faces, even though it's been a few years since I attended a meeting myself. I hope people are enjoying the meeting.

On the topic of IPv6 deployment, I'd like to ask the WG on the following issue: Turns out that, when browsing from www.ripe.net to find the URLs of the Lisbon streams, I seem to run into a PMTU blackhole issue, and, IPv6 doesn't deal with these too well. The only way around it, for me, was to switch IPv6 *OFF*. (for those curious, it looks like a PMTU blackhole to rosie.ripe.net, but I don't want to badmouth the RIPE NCC or the meeting crew - read on!)

Before you think this is another consumer-enduser, I'd like to consider that a few weeks ago, a few volunteers diagnosed a similar problem with a large public FTP server in the Netherlands. I have tcpdump logs of the PMTU packets entering the FTP server box itself, and the TCP stack not noticing. Since it's not my box, there is still work-in-progress to fix this, but it definitely is not a local problem - the PMTU packets come from the XS4all IPv6 tunnel broker box!

My question, to the WG-at-large, is this: I'm just using a consumer-grade ADSL connection, with consumer-grade helpdesk access, who is unable to deal with these issues. When IPv6 is deployed on a larger scale, problems like these are bound to happen, and, I fear, these problems happen with Joe Common who cannot diagnose these problems.

My only recourse, and certainly Joe Common's only recourse, is to switch IPv6 *OFF*. That is, umm, incompatible with the IPv6 outreach the RIPE community is currently doing.

My questions therefore: - Should these problems be discovered before large-scale deployment? - Would it be a good idea to do efforts to pro-actively detect (and correct) these problems on the infrastructure we have now, and the infrastructure we're soon deploying? - What mechanisms do we need to report these issues, so they can be addressed by people who have both clue and enable/root access to fix them? (taking into account the very nasty scaling properties of "consumer-grade helpdesk support lines" and the quality of the reports one gets from Joe Common-style users)

Again, this message is not to badmouth RIPE NCC, the Lisbon LOC, XS4all, or anybody else, but just a question on how to deal with these issues, as the current mechanisms ("consumer helpdesk") can't cope, and the recourse ("switch IPv6 off") is probably not what we want.

Comments?

Geert Jan