I have read many posts where the user states that Cisco’s Packet Tracer does not support BGP (Border Gateway Protocol). This is not the case, in the latest version of Packet Tracer 5.3.2 there is limited support for BGP.
BGP is the core routing protocol used for the entire Internet. It is best described as a path vector protocol because it does not use the traditional IGP (Interior Gateway Protocol) such as OSPF (Open Shortest Path First), EIGRP (Enhanced Interior Gateway Routing Protocol ) and RIP (Routing Information Protocol) metrics, but makes its routing decisions based on path, network policies and/or rule sets. It maintains a table of IP networks or ‘prefixes’ which is used to determine the networks ability to reach the varies AS (Autonomous Systems).
The most limiting lack in support that Packet Tracer has with BGP is the inability to create iBGP (Internal Border Gateway Protocol) peers. This means the user cannot create neighbors between routers within the same autonomous systems. Although even with this limitation there is sufficient support to allow the CCNA, and CCNP student to gain a basic understanding of this complex routing protocol and to learn how to use the following supported command within Packet tracer.
IOS commands supported in Packet Tracer 5.3.2:
Enable mode commands:
- show ip bgp: Displays the BGP routing table
- show ip bgp: neighbors Displays information about the TCP and BGP neighbors
- show ip bgp: summary Displays the status of all BGP connections
- clear ip bgp : Resets all BGP connection using BGP soft reconfiguration
Router bgp mode commands:
- log-neighbor-changes: Enable logging of BGP neighbor resets
- >redistribute-internal: Redistribution of iBGP routes into an IGP such as IS-IS or OSPF
- router-id: Configures a fixed router ID for a BGP router
- Exit
- neighbor next-hop-self: Configure the router as the next hop for a BGP neighbor
- neighbor remote-as: Add an entry to the BGP neighbor table
- network: Specify the networks to be advertised by BGP
- redistribute connected: Redistribute connected routes into the BGP routing table
- synchronization: Enable the synchronization between BGP and IGP
- timers bgp: Adjust the BGP network timers
While Cisco’s Packet Tracer provide the support available in other routing and switching simulators such as GNS3 and Boson it does allow the student the ability to gain a basic knowledge of the above commands by creating lab scenarios demonstrating topics such as BGP Multipath, Redistribution, Network Advertising, as shown in the following example: