Understanding BGP

C

BGP, which stands for Border Gateway Protocol, is an Internet protocol that is used for exchanging routing information between different Autonomous Systems (ASes) that make up the Internet. BGP is a path-vector protocol that is used to determine the best path for forwarding traffic between ASes.

Now let's examine each answer option:

A. Using BGP within your AS eliminates the need for an IGP.

This statement is not true. BGP is an external routing protocol that is used for exchanging routing information between different ASes. However, within an AS, an Interior Gateway Protocol (IGP) such as OSPF or IS-IS is still required to distribute routing information between routers within the same AS.

B. EBGP sessions have a TTL value of 64 by default.

This statement is true. By default, the Time-To-Live (TTL) value for BGP packets sent between External BGP (EBGP) peers is 64. The TTL value is used to prevent BGP packets from looping indefinitely in the network.

C. If an EBGP peer is more than one hop away, a multihop BGP session must be established.

This statement is true. By default, BGP establishes a neighbor relationship with directly connected neighbors. However, if the EBGP peer is more than one hop away, a multihop BGP session must be established by configuring the "multihop" option on both sides of the BGP peering.

D. BGP devices require a direct connection to peer with each other.

This statement is not true. While BGP can be used over a direct physical connection, it can also be used over an indirect connection through an intermediate network. BGP is a Layer 4 protocol that operates on top of TCP, which allows BGP devices to establish a connection and exchange routing information over an IP network.