BGP fundamentals
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
10-06-2023 03:59 AM
Hello engineers,
What is the significant fundamentals of BGP ?
cheersxxx
- Labels:
-
Routing Protocols
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
10-06-2023 04:51 AM - edited 10-06-2023 04:53 AM
Hello @M.Sultan,
Difficult to summurarize BGP with significant fundamentals. To much things to say!
BGP is a path vector protocol, which means it advertises the path (sequence of ASNs) that a packet should take to reach a destination network. This path information is used to make routing decisions. BGP has multiple versions, including BGP-4, which is widely used in today's networks.
An AS is a collection of IP networks and routers under the control of a single organization and sharing a common routing policy. BGP operates at the AS level, making it suitable for inter-domain routing (routing between different organizations).
BGP routers establish peering sessions with neighboring BGP routers (tcp_179). BGP sessions can be either eBGP (between routers in different ASes) or iBGP (between routers within the same AS). BGP uses a set of attributes associated with routes to make routing decisions. Find few attributes bellow:
-AS Path: A list of ASNs through which the route has passed. Helps prevent routing loops.
-Next Hop: The IP address of the next-hop router for the route,
-Prefix Length: The length of the network prefix in CIDR notation,
-Local Preference: Used in route selection within an AS,
-Weight: Cisco-specific attribute used for route selection within a router,
-MED: Used for route selection between ASes,
-Community: A tag used for policy manipulation.
BGP uses a combination of these attributes to select the best path to reach a destination. The BGP decision process evaluates attributes to determine the best route.
Net admin can apply route filters and policies to manipulate BGP routes based on specific criteria.
.ı|ı.ı|ı. If This Helps, Please Rate .ı|ı.ı|ı.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
10-06-2023 05:02 AM
Hi Sultan,
Here is a great session on BGP by a great teacher - Kevin Wallace, author of many Cisco books.
https://www.youtube.com/watch?v=SVo6cDnQQm0
regards
kazam
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
10-06-2023 05:40 AM
BGP Fundamentals convers following topics:
- BGP peer types (iBGP vs eBGP)
- BGP Session types (single hop session vs multihop session)
- BGP meesages (open, update, notification and keepalive)
- BGP peering states (idle, connect, active, open sent, open confirm, established)
- Prefix advertisement, BGP router-id and Authentication
- BGP databases (Adj-rib-in, Local-rib and Adj-rib-out)
- BGP next-hop-self command, BGP update-source command
- BGP configuration (using address-family vs without address-family)
- BGP Confederations and BGP route-reflectors
Best regards
******* If This Helps, Please Rate *******
