> -----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
