Singled Homed Exterior Border Gateway Protocol
- show ip bgp summary
- show ip bgp
- show ip bgp neighbors
- distance vector
- advertises all or a portion of its route table to its neighbors.
- Route exchange
- discovers connectivity among a set of IP subnets
- Route updates contain AS path, network, attributes
- network statement advertises network dynamically, statically, or through redistribution.
- attributes inluence best path selection.
- Autonomous systems define boundaries.
- They’re a collection of routers under common administrative control w/ a common policy displayed to the world. Tells other routers in other ASes what is has with advertising. Listens to reachability.
- VLSM support
- Summarizes any BGP router
- improves scalability
- Various metrics
- No hierarchy
- traffic between diff. BGP ASes can take different paths.
- Autonomous building blocks
- TCP port 179
- Neighbors are specifically configured
- Only exchanges routes with neighbors
- Neighbors can be in the same AS (internal BGP) or not (external BGP)
- You have to make sure they know they’re neighbors internally.
- synch. database for initial update
- incremental updates
- 60 sec. Hello
- 180 Hold
- Route reflectors
- Unicast traffic
Customer network ————— [ you ] ———— ISP
* AS numbers
yours, remotes, must be different
* neighbors involved
* networks that should be advertised.
1, Define BGP
router bgp [AS #, 1 - 65535]
2, establish neighbor relationships
neighbor x.x.x.x remote-as [AS #]
network x.x.x.x mask c.c.c.c
EMPLOYERS: This is me putting new skills into practice.