From: Eric Dumazet <eric.dumazet@gmail.com>
To: Rick Jones <rick.jones2@hp.com>
Cc: David Miller <davem@davemloft.net>, netdev <netdev@vger.kernel.org>
Subject: Re: [RFC] IP_MAX_MTU value
Date: Fri, 21 Dec 2012 10:54:05 -0800 [thread overview]
Message-ID: <1356116045.21834.7751.camel@edumazet-glaptop> (raw)
In-Reply-To: <50D4AF72.2020101@hp.com>
On Fri, 2012-12-21 at 10:50 -0800, Rick Jones wrote:
> On 12/21/2012 10:34 AM, Eric Dumazet wrote:
> > On Fri, 2012-12-21 at 10:19 -0800, Rick Jones wrote:
> >
> >> If you go beyond the protocol limit of an IPv4 datagram, won't it be
> >> necessary to start being a bit more conditional on IPv4 vs IPv6?
> >>
> >
> > This IP_MAX_MTU is really an IPv4 thing (static to net/ipv4/route.c)
>
> OK. Doesn't this:
>
> if (mtu > IP_MAX_MTU)
> mtu = IP_MAX_MTU;
>
> mean it should be OK to go to 0xFFFF but not 0x10000? Since 65535 is
> the limit of an IPv4 datagram and so I would think would be the maximum
> MTU for an IPv4 interface.
Sure, I meant 0xFFFF and it is the value I used in my tests.
65536 is the current MTU of loopback device, and this can be used by
other protocols.
next prev parent reply other threads:[~2012-12-21 18:54 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-21 6:47 [RFC] IP_MAX_MTU value Eric Dumazet
2012-12-21 7:08 ` Eric Dumazet
2012-12-21 18:19 ` Rick Jones
2012-12-21 18:34 ` Eric Dumazet
2012-12-21 18:50 ` Rick Jones
2012-12-21 18:54 ` Eric Dumazet [this message]
2012-12-21 19:59 ` David Miller
2012-12-21 23:45 ` Alexey Kuznetsov
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