-----Original Message-----
From: Stevan Pierce
Sent: Tuesday, May 01, 2001 1:59 PM
To: IETF (E-mail)
Subject: BGP Keepalive Format
Importance: High
All:
I was looking at the packet format for a BGP keepalive, when I came up
with some questions. Halabi's "Internet Routing Architecture" gives me
some pretty good info on, 19 bytes with 16 for the marker, 2 for the
length, and 1 byte for the length. Since it is a keepalive, there will be
no data following this frame; however, here is where my questions begin.
According to W. Richard Stevens' book "TCP/IP Illustrated: Volume 1", this
keepalive is an application keepalive as opposed to a TCP keepalive, page
139 last paragraph. How come? I thought that since BGP is a TCP
session-oriented protocl this keepalive would be layer 4 as opposed to
layer 7. (NOTE: I am also assuming that this keepalive is independent of
the standard TCP keepalive used by TCP/IP under normal circumstances.
My next question: Since this keepalive if 19 bytes, would I add the
standard Ethernet/802.3 encapsulation padding with the CRc to make the
datagram 6+6+2+4+19=37 bytes [destination addr+srce
addr+(length\type)+CRC+keepalive size=total datagram size]??? Also, would
this keepalive be considered part of the data portion of an ethernet\802.3
packet?
Stevan