TSHOOT – Gigantic BGP review, verification commands, and troubleshooting for exam day!

This will be the BGP Topology you will very likely be working Trouble tickets from on the TSHOOT, it could be iBGP or eBGP, and there is a whole lot of BGP to know even for that! Review of BGP BGP is called a "Path Vector" Protocol that basically is the internet at Layer 3, … Continue reading TSHOOT – Gigantic BGP review, verification commands, and troubleshooting for exam day!

Local Preference Part 2: Configuring the “Some but not all” local preference attribute, behaviors, and explanations!

Same Topology, only this time I added a second logical network between R3 and R4 by creating 2 loopback interfaces in the same subnet 210.3.3.0 /24, and removed the previous "All or none" configuration for Local Preference. So first I want to review R2 and R1 to see if their ip bgp tables look correct: … Continue reading Local Preference Part 2: Configuring the “Some but not all” local preference attribute, behaviors, and explanations!

BGP Best-Path selection process examined given its criteria for selection, IMPORTANT behaviors of iBGP vs eBGP, Next-Hop examined in detail, and more!

We are back with this Topology I believe once more before we switch gears and leave Path and Attribute discussion alone for a bit. One quick real world note, I fired up my lab and I was missing R4's loopback network / Peering across all routers, and I started troubleshooting when I stopped and saw … Continue reading BGP Best-Path selection process examined given its criteria for selection, IMPORTANT behaviors of iBGP vs eBGP, Next-Hop examined in detail, and more!

BGP Well-Known Mandatory attributes explained, Best-Path explained, configured, and VERY important details!

^ I created this mid-session, but put it here as well as I like to illustrate the struggle at the beginning of the post 🙂 There are 3 well-known and mandatory attributes a BGP Speaker includes in updates to other BGP Speakers, that they must know how to speak (or they aren't speaking BGP) which … Continue reading BGP Well-Known Mandatory attributes explained, Best-Path explained, configured, and VERY important details!