On Tue, Mar 12, 2002 at 04:59:29PM +0700, Robert Elz wrote:
> 
> You mean aside from updating the TTL, and correcting the checksum,
> dealing with source routes, router alerts, ...

Forgot the TTL!

Remember the checksum in 'linear' so when you decrement the TTL
you increment the relevant checksum byte to match.
(you need to worry if the byte is, or becomes, 0)
This saves you both validating and recalculating the full header
checksum.

	David

-- 
David Laight: david@l8s.co.uk