[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
location of the AH in IPv4
- To: ipsec@ans.net
- Subject: location of the AH in IPv4
- From: touch@ISI.EDU
- Date: Fri, 28 Jul 1995 11:23:48 -0700
- Posted-Date: Fri, 28 Jul 1995 11:23:48 -0700
Hi,
I'm a little confused about the location of the AH in
IPv4. The AH spec (draft-ietf-ipsec-auth-02.txt, 25 May '95),
says that:
0. Abstract (p 1)
AH is normally inserted after the main IP header
3. Authentication Header (p 4-5)
When used with IPv4, the AH normally follows the
main IPv4 header.
but later says:
4. Calculation... (p 8)
The IPv4 TTL and HDR-CHKSM fields are then only fields
in the IPv4 base header that...
This confuses base and main header. What is the main header?
I'm presuming the following:
A. AH comes after IPv4 base and after IPv4 options (if any)
B. IPv4 base length includes base and options only
i.e., IPv4 length points to the AH start
Is there any verification of this in the specs?
Joe
----------------------------------------------------------------------
Joe Touch touch@isi.edu
ISI / Project Leader, ATOMIC-2 http://www.isi.edu/~touch
USC / Research Assistant Prof. http://www.isi.edu/atomic2
Follow-Ups: