Can I run BGP without IGP?
Before a BGP route is advertised and added to the routing table, this route must be known via an IGP. For the case of AS65000, no IGP is used, only pure iBGP peering hence BGP synchronization will stop bgp speaker from adding routes learned by its iBGP peer to its routing table.
Why we use BGP instead of IGP?
The gist of it is that IGPs are built to operate within an autonomous system and BGP is built to operate between autonomous systems. The key difference is in the nature of intra-AS vs. The goal is to get a holistic view of the autonomous system and the need for routing policy, while there, isn’t great.
Is the BGP protocol the same as the IGP protocol?
BGP is a routing protocol, but it is not an IGP but an EGP. So it does not handle routes within the same AS, it is only for exchanging routing information between different ASn. Routing within the same AS must be handled differently. iBGP requires full mesh of iBGP routers.
Which is better for routing, iBGP or IGP?
BGP can handle many more routes than IGP protocols. Thus, iBGP is required unless you’re willing to redistribute all the routes you’ve learned via eBGP Enforce boundaries of trust / control: BGP has more ways to filter peers than IGPs (for controlling what you advertise and receive).
What is the rule of BGP for iBGP full mesh?
As for the IBGP full mesh, the rule of BGP advertisements states that “A route learned from one IBGP neighbor, should not be advertised to another IBGP neighbor”. In the above topology, R14, R15, R16, R17 are route reflectors. Ignore them for the moment and pretend that they are not present in the diagram.
Can you use iBGP in an internal network?
If you do look at using iBGP heavily in your internal network you need to start thinking about full mesh requirements. This means looking down the path of Route Reflectors, or perhaps Confederations (if you’re large enough).