[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [lwip-users] Don't fragment flag
|
From: |
Kieran Mansley |
|
Subject: |
Re: [lwip-users] Don't fragment flag |
|
Date: |
Wed, 22 Mar 2006 09:16:17 +0000 |
On Wed, 2006-03-22 at 10:06 +0100, Jan Ulvesten wrote:
> The flag tells the underlying network to don’t fragment the IP packet?
> Why making such a requirement?
I'm not sure why it's like that in lwIP, but more generally you might
set this bit if you're doing path MTU discovery, and so believe you have
chosen an MTU that should not need fragmenting. If you set this bit,
and it turns out the packet does need fragmenting, you'll get an ICMP
message telling you this from whoever drops the packet, and so you can
update your MTU for future packets.
Kieran