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  • Debugging SLAAC

    From Alexander Koeppe@21:1/5 to All on Sun Nov 12 13:30:01 2017
    Hello list,

    just recently I've had issues that SLAAC didn't worked out for a while
    and started working again w/o knowing the reason.

    I tried to sniff ICMPv6 packets, saw the RAs coming around every 5-6
    minutes, but my net adapter didn't configured itself with a GUA derived
    from the prefix in the RA.

    Is there any possiblitiy to increase the debug level to troubleshoot
    issues with the address generation?

    Checked dmesg, but didn't relveal much.

    Regards - Alex

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  • From Pascal-liste@21:1/5 to All on Sun Nov 12 15:50:01 2017
    Hello,

    Le 12/11/2017 à 13:28, Alexander Koeppe a écrit :

    just recently I've had issues that SLAAC didn't worked out for a while
    and started working again w/o knowing the reason.

    I tried to sniff ICMPv6 packets, saw the RAs coming around every 5-6
    minutes, but my net adapter didn't configured itself with a GUA derived
    from the prefix in the RA.

    Did you see Router Solicitation packets sent by the interface after the
    link was activated ?
    Did the host set at least prefixes/routes from the RAs ?

    What manages the interface ? Is SLAAC enabled for the interface in /proc/sys/net/ipv6/conf/ ?
    Are NDP ICMPv6 packets allowed by the firewall rules ?

    Is there any possiblitiy to increase the debug level to troubleshoot
    issues with the address generation?

    Checked dmesg, but didn't relveal much.

    Did you see the message saying that no IPv6 routers were found ?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Alexander Koeppe@21:1/5 to All on Tue Nov 14 23:30:01 2017
    Am 12.11.2017 um 15:38 schrieb Pascal-liste:
    Hello,


    Hi

    Did you see Router Solicitation packets sent by the interface after the
    link was activated ?
    Did the host set at least prefixes/routes from the RAs ?

    I also thought about it. No router solicitations seen, going out from my
    host on which i ran Wireshark. So seem really pointing to a local issue
    on my Debian machine. The only IPv6 prefix on the interface was the
    link-local.

    What manages the interface ? Is SLAAC enabled for the interface in /proc/sys/net/ipv6/conf/ ?
    Are NDP ICMPv6 packets allowed by the firewall rules ?

    The interface is configured in /etc/network/interfaces.d/, so
    NetworkManager is out of the game. At the time the issue was present, I
    missed to check /proc, however nothing changed and AFAICS everything
    necessary is enabled. There is also no filtering between the host and
    the router.

    Did you see the message saying that no IPv6 routers were found ?

    Nothing like that. That's actuall I hoped to see.

    So essentialy that's what I'm looking for. Maybe a /proc or /sys entry
    to be modified to increase the kernel logging for the SLAAC process. Or
    maybe a kernel parameter set at boot.....

    Thanks
    - Alex

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    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Marc Haber@21:1/5 to Alexander Koeppe on Wed Nov 15 09:50:02 2017
    On Sun, Nov 12, 2017 at 01:28:54PM +0100, Alexander Koeppe wrote:
    just recently I've had issues that SLAAC didn't worked out for a while
    and started working again w/o knowing the reason.

    There is the rdisc6 tool that I have used quite some times to debug
    SLAAC issues. You can use it to send out your own router solicitations,
    and to see what's in the advertisement.

    Greetings
    Marc

    -- ----------------------------------------------------------------------------- Marc Haber | "I don't trust Computers. They | Mailadresse im Header Leimen, Germany | lose things." Winona Ryder | Fon: *49 6224 1600402 Nordisch by Nature | How to make an American Quilt | Fax: *49 6224 1600421

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Alexander Koeppe@21:1/5 to All on Thu Nov 23 23:30:02 2017
    Am 15.11.2017 um 08:58 schrieb Hagen Paul Pfeifer:


    You are using the stock Debian Kernel - right? No self-backed version.

    Hagen


    Yes, but I've no issues in making up a custom kernel.
    Anything to enabled there to increase verbosity?

    --- SoupGate-Win32 v1.05
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  • From Alexander Koeppe@21:1/5 to All on Thu Nov 23 23:40:01 2017
    Am 15.11.2017 um 09:48 schrieb Marc Haber:

    There is the rdisc6 tool that I have used quite some times to debug
    SLAAC issues. You can use it to send out your own router solicitations,
    and to see what's in the advertisement.

    Greetings
    Marc


    Thanks. Will take a look at rdisc6.

    - Alex

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)