Subject: IKEv2: prepending four octets

From: ravi <[email-masked]>
Date: Tue, 18 Mar 2003 18:37:48 +0530

Dear All,
I am going through the ikev2-0.5 draft.It says
In the IKE header when sent on UDP port 4500 ,IKE messages have 
prepended four octets of Zero.

My doubt is what made to prepend four octets of Zeroes before the IKE 
message.
Thanks in advance,
Ravi Kumar CH.