Which of the following BGP message types are exchanged between BGP peers? (Choose two)

BGP establishes a TCP-based session between peers and exchanges routing information. The first message sent after the TCP connection is established is the OPEN message, used to negotiate session parameters and establish the peering. Once the session is established, UPDATE messages are used to advertise new routes, withdraw previously advertised routes, and communicate path attributes. These two message types are fundamental to establishing a BGP session and exchanging network reachability information. Keepalive messages are also used, but their role is session maintenance rather than establishment or information exchange.

B. Keepalive: While a valid BGP message type, its primary purpose is to maintain the BGP session (acting as a heartbeat), not to establish it or exchange routing information.

D. Hello: This is a packet type used by Interior Gateway Protocols like OSPF and IS-IS for neighbor discovery. BGP does not use Hello messages.

- RFC 4271

"A Border Gateway Protocol 4 (BGP-4)

" Section 4

"BGP Messages." This section defines the four BGP message types: OPEN

UPDATE

NOTIFICATION

and KEEPALIVE.

- Juniper Networks TechLibrary

"Junos OS Routing Protocols Library for Routing Devices

" BGP Overview

"BGP Message Types." This document details the purpose of each message

specifying that OPEN is for establishing a connection and UPDATE is for transferring routing information.