nanog mailing list archives
Re: evil ipv6 bit?
From: Hugo Slabbert <hugo () slabnet com>
Date: Fri, 26 Jan 2018 09:35:45 -0800
On Fri 2018-Jan-26 15:55:58 +0000, Saku Ytti <saku () ytti fi> wrote:
On 26 January 2018 at 03:50, Baldur Norddahl <baldur.norddahl () gmail com> wrote:I just now discovered this: google.com: 2a00:1450:400e:807::200e That address works fine. But then I changed that one bit in the address: 2a00:1450:400e:8807::200e and voila, the router drops the packet. Now I am stumbled. What could the 49th bit in the destination IPv6 address field in a packet mean to the router, that would make it drop the packet?Are you sure it is dropped? Can you see some drop counter increase? Have you observed nothing coming out from any port? My guess is bad memory, and that bit is statically set or statically unset and cannot be changed. Might cause CRC error, IP checksum error or just mangled packet coming out of the router -- ++ytti
There was also this example from a while ago: *Juniper MX80 strange dst MAC address behavior* https://mailman.nanog.org/pipermail/nanog/2017-November/092954.html And then this:*Forwarding issues related to MACs starting with a 4 or a 6 (Was: [c-nsp] Wierd MPLS/VPLS issue)*
https://mailman.nanog.org/pipermail/nanog/2016-December/089395.html Those are both related to _MACs_, though, rather than IPs. -- Hugo Slabbert | email, xmpp/jabber: hugo () slabnet com pgp key: B178313E | also on Signal
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Current thread:
- evil ipv6 bit? Baldur Norddahl (Jan 25)
- Re: evil ipv6 bit? Saku Ytti (Jan 26)
- Re: evil ipv6 bit? Hugo Slabbert (Jan 26)
- Re: evil ipv6 bit? Theodore Baschak (Jan 26)
- Re: evil ipv6 bit? Saku Ytti (Jan 26)