Solved: EIGRP & BGP

edsantos1 · ‎03-30-2006

Hi,

In one of the below posts titled "EIGRP Query" someone asked which query types were reliable and which were not. Queries, updates and replies are reliable and Hello and Ack are not. I'm just intrigued to know why EIGRP uses IP and not TCP if it requires reliability. Also, why does BGP use TCP if it is a routing protocol??

Thanks

Ed

pkhatri · ‎03-30-2006

Hi Ed,

EIGRP uses multicast traffic but TCP provides reliability for only unicast traffic. That's why TCP could not be used and that is why the developers of EIGRP developed the Reliable Transport Protocol (RTP) which does provide reliability when using multicast traffic.

BGP uses TCP because it is well suited to the point-to-point requirements of BGP peering. Just because BGP is a routing protocol does not mean that it can't use a transport layer like TCP or UDP. In fact, even RIP uses UDP as the underlying transport.

Pls do rate the post if it helps.

Paresh

View solution in original post

pkhatri · ‎03-30-2006

Hi Ed,

EIGRP uses multicast traffic but TCP provides reliability for only unicast traffic. That's why TCP could not be used and that is why the developers of EIGRP developed the Reliable Transport Protocol (RTP) which does provide reliability when using multicast traffic.

BGP uses TCP because it is well suited to the point-to-point requirements of BGP peering. Just because BGP is a routing protocol does not mean that it can't use a transport layer like TCP or UDP. In fact, even RIP uses UDP as the underlying transport.

Pls do rate the post if it helps.

Paresh