What this lab is for
This lab is designed to make one BGP route feel concrete. It uses two private ASNs, one eBGP neighbor relationship, and one documentation prefix that stays inside a closed lab.
prefix: 203.0.113.0/24 next hop: 10.0.0.1 as path: 65001 origin: IGP
By the end, the target is to explain that route as prefix + path attributes, not just as a line in a routing table.
The experiment
The draft lab builds two virtual routers. AS65001 advertises 203.0.113.0/24 to AS65002. The receiving side observes the route, then maps the output back to RFC terms.
| Observed value | Protocol meaning |
|---|---|
203.0.113.0/24 |
NLRI, the prefix being advertised. |
10.0.0.1 |
NEXT_HOP, the address to use when forwarding toward the advertised prefix. |
65001 |
AS_PATH, showing that the route originated from AS65001 in this small lab. |
IGP |
ORIGIN, the BGP origin attribute produced by the local configuration. |
RFC reading path
Lab 01 reads a narrow slice of RFC 4271 before touching the command line. The goal is to connect terms to observable behavior.
- Section 1.1 for AS, BGP speaker, EBGP, IBGP, NLRI, and Route.
- Section 3.1 for the idea that a route is a prefix plus path attributes.
- Section 4.3 for the UPDATE message layout.
- Section 5 for ORIGIN, AS_PATH, and NEXT_HOP as mandatory path attributes.
Run the full lab
The full hands-on walkthrough is now published. It covers the containerlab topology, FRRouting configs, BGP table inspection, packet capture, common pitfalls, and a verified execution log captured on Ubuntu 24.04 with FRRouting and containerlab 0.75.0.
203.0.113.0/24 is a documentation prefix. The lab keeps it inside a local environment and does not advertise anything to the public Internet.
Next labs
After this first route is understandable, the track can add route withdrawal, a three-AS path, competing origins, and RPKI origin validation.
Lesson navigation
次の hands-on では UPDATE による advertisement と withdrawal を見て、同じ route がどう状態遷移するかを追います。