On 04/01/2016 07:21 PM, Eric Dumazet wrote:
On Fri, 2016-04-01 at 22:16 -0400, David Miller wrote:
From: Alexander Duyck <alexander.du...@gmail.com>
Date: Fri, 1 Apr 2016 12:58:41 -0700
RFC 6864 is pretty explicit about this, IPv4 ID used only for
fragmentation. https://tools.ietf.org/html/rfc6864#section-4.1
The goal with this change is to try and keep most of the existing
behavior in tact without violating this rule? I would think the
sequence number should give you the ability to infer a drop in the
case of TCP. In the case of UDP tunnels we are now getting a bit more
data since we were ignoring the outer IP header ID before.
When retransmits happen, the sequence numbers are the same. But you
can then use the IP ID to see exactly what happened. You can even
tell if multiple retransmits got reordered.
Eric's use case is extremely useful, and flat out eliminates ambiguity
when analyzing TCP traces.
Yes, our team (including Van Jacobson ;) ) would be sad to not have
sequential IP ID (but then we don't have them for IPv6 ;) )
Your team would not be the only one sad to see that go away.
rick jones
Since the cost of generating them is pretty small (inet->inet_id
counter), we probably should keep them in linux. Their usage will phase
out as IPv6 wins the Internet war...
