EUROPEAN AUTONOMOUS SYSTEM NUMBER APPLICATION FORM & SUPPORTING NOTES Document-ID: ripe-91.txt Expiry Date: 28 February 1994 To whom it may concern. Thank you for your request for an Autonomous System (AS) number. The documentation below consists of two sections : the first section refers to SUPPORTING NOTES which give a definition and description of what an Autonomous System is, together with a description of when an AS number is needed and necessary. It is important that you read this section carefully. The second section, the AS NUMBER TEMPLATE is the actual template that must be completed and returned to the RIPE Network Coordination Centre (NCC). The template is divided into two parts: Part A - Administrative Details Part B - Technical Details You must complete part A in full. This is Mandatory. Part B should also be filled in, but at the time of application you may not know all the technical details. You can still get an AS number without completing Part B, but you are urged to submit the information as soon as possible. Please ensure that you read all the information below care- fully before submitting your application for an AS number. For more detailed explanations please refer to the paper "Representation of IP Routing Policies in the RIPE Database" RIPE document ID: ripe-081. If you have any queries, please do not hesitate to con- tact the RIPE NCC who will be able to advise you. Our con- tact details are given below: RIPE NCC email: hostmaster@ripe.net Kruislaan 409 tel: +31 20 592 5065 1098 SJ Amsterdam fax: +31 20 592 5090 The Netherlands Yours sincerely. hostmaster@ripe.net RIPE Network Coordination Centre September 3, 1993 ripe-91.txt - 2 - Expires 28/02/94 SUPPORTING NOTES for AUTONOMOUS SYSTEM (AS) NUMBER REQUESTS Please read the information below carefully. It is impor- tant that you read this before completing the template in the following section as it contains essential definitions. What is an Autonomous System ? An Autonomous System (AS) is a group of IP networks run by one or more network operators which has a single and clearly defined routing policy. An AS has a unique number associated with it which is used in both the exchange of exterior routing information (i.e. network reachability information between ASes) and as an identifier of the AS itself. Exterior routing protocols such as BGP and EGP are used to exchange routing information between ASes. In routing terms an AS will normally use one or more inte- rior gateway protocols when exchanging network information within its own AS. The term AS is often confused or even misused as a con- venient way of grouping together a set of networks which belong under the same administrative umbrella even if within that group of networks there are various different routing policies. ASes can strictly have only one single routing policy. On the other hand, the creation of an AS should be done in a conscious and well coordinated manner to avoid creating ASes for the sake of it, perhaps resulting in the worst case scenario of one AS per IP network number. This may mean that by applying the general rules for the creation and alloca- tion of an AS below, some re-engineering may be needed. How- ever, this may be the only way to actually implement a desired routing policy anyway. How can I be sure I need an AS number ? o Creation of an AS is only required when exchanging routing information with other ASes. Some router imple- mentations make use of an AS number as a form of tag- ging to identify the routing process. However, it should be noted that this tag does not need to be unique unless routing information is indeed exchanged with other ASes. September 3, 1993 ripe-91.txt - 3 - Expires 28/02/94 o An IP network number can and must only belong to one AS. This is a direct consequence of the fact that at each point in the Internet there can only be exactly one routing policy for traffic destined to each net- work. In the case of the IP network which is used in neighbor peering between two ASes, say at the border between two ASes, a conscious decision must be made as to which AS this IP network number actually resides in. o For a simple case of customer networks connected to a single service provider, the IP network should be a member of the service provider's AS. In terms of rout- ing policy the IP network has exactly the same policy as the service provider and there is no need to make any distinction in routing information. This idea may at first seem slightly alien to some, but it highlights the clear distinction in the use of the AS number as a representation of routing policy as opposed to some form of administrative use. o If a network operator connects to more than one AS with different routing policies then they need to create their own AS. In the case of multi-homed customer net- works connected to two service providers there are at least two different routing policies to a given custo- mer network. At this point the customer networks will be part of a single AS and this AS would be distinct from either of the service providers ASes. This allows the customer the ability of having a different representation of policy and preference to the dif- ferent service providers. This is the ONLY case where a network operator should create its own AS number. o As a general rule one should always try to populate the AS with as many IP networks as possible, providing all IP networks conform to the same routing policy. Each AS is represented in the RIPE database by an AS object. The AS object stores descriptive, administrative and contact information about the AS as well as the technical informa- tion relating to the routing policies of the AS in relation to all neighboring ASes. September 3, 1993 ripe-91.txt - 4 - Expires 28/02/94 Example of a completed allocated AS number template which contains information which is stored in the RIPE Network Management Database. aut-num: AS1104 descr: NIKHEF-H Autonomous system tech-c: Rob Blokzijl admin-c: Eric Wassenaar source: RIPE changed: k13@nikhef.nl 920713 changed: ripe-dbm@ripe.net 920910 as-in: AS1213 100 AS1213 as-in: AS1913 100 AS1913 as-in: AS1755 150 ANY as-out: AS1213 ANY as-out: AS1913 ANY as-out: AS1755 AS1104 AS1913 AS1213 guardian: as-guardian@nikhef.nl This example contains Part B - technical details "routing policy" information which it is not strictly necessary to supply in the initial application for an AS number, but which you are strongly urged to complete in the future when you know your "routing policy". This is especially important if you intend to connect to the Global Internet at some stage in the future. It is important to note that if you decide to send in your "routing policy" later on, then you MUST accompany it with the full administrative information. Otherwise we will not know to which autonomous system and to which organisation the routing information applies! September 3, 1993 ripe-91.txt - 5 - Expires 28/02/94 Part A - Administrative Details ADMINISTRATIVE TEMPLATE aut-num: How many AS numbers do you require? Format: Please complete with a number Example: aut-num: 1 descr: A short description of the Autonomous system. Format: free text, multiple lines in sequence allowed as in example below Example: descr: NIKHEF section H descr: Science Park Watergraafsmeer descr: Amsterdam tech-c: Name or NIC-handle of technical contact person. This is someone to be contacted for technical problems such as misconfiguration, etc. Format: , multiple lines. Example: tech-c: John E. Doe admin-c: Name or NIC-handle of administrative contact person. This is most likely to be the same name as the guardian but it is not mandatory for it to be. Format: , multiple lines. Example: admin-c: Joe T. Bloggs changed: Email address of the person who is completing the template, followed by the current date. If you do not have email connectivity please leave blank and we September 3, 1993 ripe-91.txt - 6 - Expires 28/02/94 will complete it. Format: as shown below. Example: changed: johndoe@terabit.nl 930225 source: RIPE Source of the information. It will always be RIPE. This is information which is always required in the database, so it has been added already. September 3, 1993 ripe-91.txt - 7 - Expires 28/02/94 Part B - Technical Details You may not at the time of applying for your AS number know the technical details requested below. Therefore we do not make completing this section mandatory. However, you are *strongly urged* to complete this section as soon as possi- ble once you know your routing policy and return your amended template to for inclusion in the RIPE Network Management Database. Please note, that if you send this section in later, you must send it in accom- panied by a completed Section A - Administrative Details otherwise we will not know to which AS or which organisation the routing policy information applies. TECHNICAL TEMPLATE as-in: A description of accepted routing information from neighboring ASes. Format: , on multiple lines. where: refers to your neighboring AS. is a positive integer used to express a relative cost of routes learned. The lower the cost the more preferred the route. can take the following for- mats: 1. A list of one or more ASes. Example: as-in: AS1103 100 AS1103 as-in: AS786 105 AS1103 as-in: AS786 10 AS786 as-in: AS1755 110 AS1103 AS786 2. A set of KEYWORDS. The following keywords are currently defined. Example: ANY - this means anything the neighbor AS knows. RIPE-DB - any network currently in the RIPE database. LOCAL - any network in the RIPE database which is part September 3, 1993 ripe-91.txt - 8 - Expires 28/02/94 of the community LOCAL (i.e. no connectivity outside its own organisation). 3. A logical expression of either 1 or 2 above. The current logical operators are defined as: AND OR NOT Rules are grouped together using parenthesis i.e "(" and ")". Example: as-in: AS1755 100 RIPE-DB AND NOT (LOCAL AS513) as-in: AS1755 150 DEFAULT as-out: A description of generated routing information sent to other AS peers. Format: , multiple lines. Where: refers to your AS neighbor. is explained in the as-in definition Example: as-out: AS1104 AS978 as-out: AS1755 ANY as-out: AS786 RIPE-DB AND NOT (AS978 LOCAL) default: An indication of how default routing is done. Format: , multiple lines. Where: The AS peer you will default route to. The relative cost is a positive integer use to express a preference for default. There is no relationship to the cost used in the "as-in" tag. The lower the cost indicates which AS peer is more pre- ferred for default. Example: default: AS1755 10 default: AS786 5 guardian: September 3, 1993 ripe-91.txt - 9 - Expires 28/02/94 Mailbox address of the guardian of the Autonomous Sys- tem Format: , single line. This should be in RFC822 format wherever possible. Example: guardian: as1104-guardian@nikhef.nl September 3, 1993 ripe-91.txt - 10 - Expires 28/02/94 EUROPEAN AUTONOMOUS SYSTEM NUMBER APPLICATION FORM Part A - ADMINISTRATIVE TEMPLATE aut-num: descr: tech-c: admin-c: source: RIPE changed: Part B - TECHNICAL TEMPLATE as-in: as-in: as-in: as-out: as-out: as-out: guardian: Please return this completed template to . You can also send it by fax. Mark your fax for the attention of RIPE NCC HOSTMASTER. Our fax number is +31 20 592 5090. September 3, 1993