- A Mnemonic for remembering BGP Path Selection Criteria courtesy maloy & jing apuhin’s 101 & others blog.
- Here’s my own mnemonic that, of course, I like better:
Next, (eliminate inaccessible next hops)
We (Weight)
Prefer (Local Preference)
Local (Locally inserted)
Paths (AS Path)
Originated by (Origin Code)
Multiple (MED)
External (prefer EBGP over IBGP)
Costly (if multiple IBGP, choose least cost exit)
Old (if multiple EBGP, choose oldest)
Routers (lowest Router ID)
- Customer BGP policies for major service providers:
AT&T, Sprint, XO Communications, Veroxity, Level 3, Verizon Business (MCI), Cogent, Cable & Wireless
- BGP related documents at cisco.com:
Configuring BGP,
Understanding Route Aggregation,
Using the BGP for Interdomain Routing,
Regular Expressions,
Using Regular Expressions in BGP,
Using Communities to Influence Upstream Policy,
BGP Best Path Selection Algorithm,
BGP Case Studies
- BGP is defined in RFC 1771 (March, 1995)
- Jeff Doyle On IP Routing
- A list of service provider looking glass routers. Telnet to these to query BGP databases.
- Making BGP Our Core Enterprise Routing Protocol (Michael Morris, Network World)
- A Visual Display of BGP Updates BGPlay is a Java application which displays animated graphs of the routing activity of a certain prefix within a specified time interval. Its graphical nature makes it much easier to understand how BGP updates affect the routing of a specific prefix
- IP Prefixes Typically Filtered by ISPs
- A DSCP chart (.xls format)
- Configurations for Cisco BGP Labs BB routers
- showipbgp.com is a great site with information about BGP.
