Subject: Re: [RFC] IP_MAX_MTU value

From: Rick Jones <[email-masked]>
Date: Fri, 21 Dec 2012 10:50:26 -0800

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.

rick