ASN

1
ASN
2
Policy Based Routing

• end-user end-user
• 
  
• 
  ISP
• 
  Regional Transit Provider
• Backbone
• Provider
• 
  BlueLight Goody2Shoes
• 
  

3
Autonomous System

• Definition
• a group of IP networks run by one or more network
  operators which has a unique and clearly defined
  routing policy
• RIR is allocated a range of AS numbers by IANA
• 16 bit number
• RIR assigns unique AS number
• for LIR or for the customer
• AS number, routing policy and originating routes
  are registered in the Routing Registry

4
How To Get an AS Number ?

• Provide information on
• at least two peering ASNs
• address space to be announced from new AS
• Being multihomed and routing policy are
  mandatory!

5
RIPE-181 Language

• RIPE-181 used to describe routing policies
• Developed in PRIDE project
• accepted in IRR and translated into RFC-1786
• Example syntax
• aut-num NEW
• as-out to AS3 announce NEW
• as-in from AS2 200 accept AS2
• Cost defines the preference
• the lower the cost, the more preferred route
• cost relative per aut-num object

6
AS Example 1
as-in from AS2 10 accept AS2 as-out to NEW
announce AS2
7
AS Example 2
as-in from AS2 10 accept AS2
as-out to NEW announce AS2
ANY
as-in from AS2 200 accept ANY
8
aut-num Object

• aut-num NEW
• descr Bluelight AS
• as-in from AS2 10 accept AS2
• as-in from AS2 200 accept ANY
• as-in from AS3 100 accept ANY
• as-out to AS3 announce NEW
• as-out to AS2 announce NEW
• default AS2 5
• admin-c JJ231-RIPE
• tech-c JAJA1-RIPE
• mnt-by NEW-MNT
• changed hostmaster_at_ripe.net 19991010
• source RIPE

AS42
AS42
AS42
BLUELIGHT-MNT

9
The Route Object

• route 195.35.64/19
• descr BLUELIGHT-NET
• origin AS42
• mnt-by BLUELIGHT-MNT
• changed hostmaster_at_bluelight.com 19991010
• source RIPE
• Represents a route in the Internet
• This route originates in AS42
• Only one origin recommended

10
as-macro

• as-macro AS-ARCON
• descr ARCON TML customers AS list
• as-list AS8955 AS6809 AS12500 AS9039
• tech-c BZ318-RIPE
• admin-c VV82
• mnt-by ARCON-MNT
• changed roman_at_itar-tass.com 19990914
• source RIPE

11
as-macro Usage

• aut-num AS8955
• descr ARCON Autonomous System
• ...
• as-out to AS8563 announce AS-ARCON
• as-out to AS2854 announce AS-ARCON
• ...
• aut-num AS8563
• descr DirectNet Autonomous System
• descr JSC DirectNet Telecommunications
• as-in from AS8955 100 accept AS-ARCON
• ...

12
Internet Routing Registry

• Globally distributed DB with routing policy
  information
• provides a map of global routing policy
• shows routing policy between any two ASes
• allows simulation of routing policy effects
• enables router configuration
• provides contact information
• RIPE Routing Registry
• subset of information in RIPE database
• syntax description in ripe-181

13
RR Tools

• RAToolSet
• sources http//www.isi.edu/ra/
• AS Object Editor (aoe)
• Aggregation optimisation (CIDR Advisor)
• Configuration (rtconfig)
• Visualisation Tool (ASExplorer)
• IRRj (http//www.merit.net/ipma/javairr/irr.html)
• java interface to IRR
• prtraceroute
• Looking glasses
• http//www.ripe.net/cgi-bin/looking-glass
• http//www.traceroute.org/

14
Special Projects(Part of RIPE NCC Public
Services)

• Routing Information Service
• collect routing information
• between Autonomous Systems (AS)
• development over time
• information available to the RIPE community
• improve network operations
• Routing Registry Consistency Project
• improve data quality in the Internet routing
  registry
• improve data accessibility and processing
  capabilities

15
Next Generation - RPSL

• New language is being developed Routing Policy
  Specification Language
• allows for more refined policy details
• will eventually replace ripe-181
• transition to RPSL will be smooth
• Test
• rpslii.ripe.net
• Re-implementation
• reimp.ripe.net at port 43
• ltauto-rip_at_ripe.netgt