IDNOG 2: AS interconnection in indonesia

Issue Date:

Revision:

ASN distribution and interconnection in Indonesia

12 June 2015

1.0

Overview

Introduction to ASN: What is it, how to get it, and why is it important?

2-byte and 4-byte ASN

ASNs in Indonesia: Distribution and Interconnection

AS interconnection: It’s about cost, resiliency and performance

Looking ahead

Introduction to ASN

Routing the Internet

• Every Internet router needs to know the relative location of every destination address on the Internet

• Location information is distributed across the Internet using routing architecture

• The Internet is divided into “clouds” of interconnection called “networks”– Interior routing protocols (OSPF, IS-IS, etc) maintain the internal

connectedness with a network– Exterior routing protocols (BGP) maintain a map of how each of

these networks connect to each other– BGP uses the concept of an Autonomous System Number to

uniquely identify each component network

Routing and ASN

• RFC 1930:– An AS (Autonomous System) is a connected group of one or more IP

prefixes run by one or more network operators that has a SINGLE and CLEARLY DEFINED routing policy.

– An AS has a globally unique number (sometimes referred to as an ASN, or Autonomous System Number) associated with it. This number is used in both the exchange of exterior routing information (between neighbouring AS’s), and as an identifier of the AS itself.

ASN distribution

2-byte and 4-byte ASN

• 2-byte (16 bit ASN)– Range: 0 – 65535– Reserved: 0, 65535– Documentation & Sample Code Use: 64496-64511– Private Use: 64512 – 65534– Public Use: 1 – 64495 (‘23456’ is used for 4-byte transition purposes)

• 4-byte (32 bit ASN)– Range: 0 – 4294967295– Additional Reserved: 65552 – 131071, 4294967295– Additional Doc. & Sample Code Use: 65536 – 65551– Additional Private Use: 4200000000 – 4294967294– Additional Public Use: 131072 – 4199999999

2-byte ASN status

199 remain at IANA (as of 8 June 2015)

http://www.potaroo.net/tools/asn16/

4-byte ASN deployment

• A few issues due to old equipment & network operating systems– Better acceptance now

in all regions

• Can not be used in BGP community attribute– BGP community attribute

is a 32-bit value, the lower 16-bit specifies the ASN

• Otherwise it WORKS JUST FINE

AS interconnection

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The Internet

• Networks worldwide interconnect to form the Internet. They include ISPs, Internet Exchange Points, Universities, Corporate networks, etc.

• Each dot represents an AS

• There are 47,000+ ASNs currently active in the Internet

peer1.com

Network Interconnection

202.178.112.0/242400:3E00:DD::/48 202.178.112.0/24

2400:3E00:DD::/48

Multi-homed networkMAY have a need for BGP and public ASN

Single-homed networkNo need for public ASN

Why multihome with BGP and use a public ASN?

Good interconnection strategy can lower cost of operation by directing traffic through the most cost effective connections wherever possible

Understanding where your network traffic goes and when possible shortening the path to your main customers/suppliers/partners could result in better overall network experience

Looking further than next hop path diversification allows you to better evaluate interconnection options, which in turn could result in better network resiliency

Cost

Performance

Resilience

Global AS Core

Economy level ASN transit map

Data source

• Routeviews.org– RIBs from routers located in various locations (mostly Internet

Exchanges) around the world (US, Japan, Korea, UK, Australia, Brazil, Singapore, Serbia)

• First week of April 2015 data

• RIBs collected every two hours– This is a snapshot, not live data

• This visualisation tool is a work in progress– APNIC values your feedback

ExplanationTop view Side view


ASNs with more downstreams are displayed closer to the centre


Lowest ASN shown at the top, followed by higher ASNs in a clockwise direction


Darker nodes/path means there are more IP addresses involved in that route


Maximum observed path length

Singapore

Malaysia

Philippines

Thailand

Indonesia530 advertised ASNs

4-byte ASN in Indonesia

4-byte range



Measurements by the Atlas project

RIPE Atlas employs a global network of probes that measure Internet connectivity and reachability, providing an unprecedented understanding of the state of the Internet in real time

https://atlas.ripe.net/ Need more probes in Indonesia

https://atlas.ripe.net/

https://atlas.ripe.net/

Domestic/International path


AS4796

AS59785


AS4796

AS38158

Transit & peering view

• Visibility of private peerings, which can not be seen on the global routing table

Need your help

• More Atlas probes on different ASNs, cities, transit paths, exchanges, etc.

Looking ahead

• As more organisations interconnect with upstreams, downstreams and peers, the number of advertised ASNs will continue to grow

• Opportunities to reduce cost, improve resiliency and performance will be available to those with awareness of this rich network ecosystem

• New technologies such as SDN and network virtualisation will drive innovations and change the way networks are interconnected, so expect to see a more dynamic ecosystem in the future

Things to consider if you operate an ASN

Routing Security

Registration

Aggregation

Routing security

• As more networks interconnect, security and stability risks such as route hijacking, accidental route leakage and other issues can escalate

• Register and maintain your ‘route’ and ‘route6’ objects in the APNIC Whois database– Ensure the import and export attributes accurately reflect your actual

routing policy

• Create your ROA– A ROA or Route Origin Authorization is an attestation of a BGP route

announcement. It attests that the origin AS number is authorized to announce the prefix(es). The attestation can be verified cryptographically using RPKI

http://www.apnic.net/rpki

ROA

• Create your ROA now in MyAPNIC (or ask IDNIC)

• Benefits– Verify whether an AS is authorized to announce a specific IP prefix– Minimize common routing errors– Prevent most accidental hijacks

• What's contained in a ROA– The AS number you authorize– The prefix that is being originated from it– The most specific prefix (maximum length) that the AS may announce

• Example of what a ROA says in plain language:– "ISP 4 permits AS 65000 to originate a route for the prefix

192.2.200.0/24"http://www.apnic.net/roa

Registration

• With IPv4 address space nearing exhaustion and transfers taking place, it’s really important that everyone keeps the resource registry updated

• Protect your Internet resource registration information– Keep your APNIC Whois data up to date

• IPv4 range (inetnum)• IPv6 range (inet6num)• ASN (autnum)• Admin contact (admin-c)• Technical contact (tech-c)• Incident Response Team contact (irt)

• Help everyone resolve operational issues quickly– Report invalid contacts

Aggregation

• As more routing information entries get added to the global routing table, it’s important that prefix announcements are aggregated whenever possible

• The algorithm used in the report (see next slide) proposes aggregation only when there is a precise match using AS path so as to preserve traffic transit policies. Aggregation is also proposed across non-advertised address space ('holes').

http://www.cidr-report.org

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