nanog mailing list archives
Re: mtu question
From: Mark Smith <nanog () 85d5b20a518b8f6864949bd940457dc124746ddc nosense org>
Date: Thu, 18 Nov 2010 08:18:10 +1030
On Wed, 17 Nov 2010 16:23:54 -0500 Brandon Kim <brandon.kim () brandontek com> wrote:
Jack brings up a good point. MTU is basically pointless since packets never traverse any real interface....... So in theory the size can be anything...
Not quite. You hit packet length field limits. IPv4 packets can't be larger than 65535, and IPv6 packets also can't be larger than 65 576 (40 byte IPv6 header + 2^16 payload), unless the jumbograms and the jumbo payload extension header is supported. Last time I checked, by setting the loopback MTU > 65 576, Linux, for example, doesn't support the jumbo payload extension header (or if it does, I didn't spend enough time finding out how to switch it on - a very large MTU didn't trigger it). That being said, with a 64K MTU on loopback, you can legitimately claim to get >10Gbps at home, as long as you don't mention how you're doing it ;-) Regards, Mark.
Current thread:
- mtu question Deric Kwok (Nov 17)
- Re: mtu question Owen DeLong (Nov 17)
- Re: mtu question Jack Bates (Nov 17)
- RE: mtu question Brandon Kim (Nov 17)
- Re: mtu question Mark Smith (Nov 17)
- RE: mtu question Brandon Kim (Nov 17)
- RE: mtu question Brandon Kim (Nov 17)
- Re: mtu question Pete Lumbis (Nov 17)