Internet Assigned Numbers Authority

Route Distinguisher Type Field

Last Updated
Route Distinguishers are used to create VPN-IPv4 addresses, as specified 
in [RFC4364]. The RDs are structured so that every service provider can 
administer its own "numbering space" (i.e., can make its own assignments 
of RDs), without conflicting with the RD assignmentsmade by any other 
service provider. An RD consists of three fields: a type field, an 
administrator field, and an assigned number field.

The value of the type field determines the lengths of the other two fields,
as well as the semantics of the administrator field. The administrator
field identifies an assigned number authority, and the assigned number
field contains a number which has been assigned, by the identified
authority, for a particular purpose.
Available Formats



Plain text

Registry included below

Route Distinguisher Type Field

Available Formats

Range Registration Procedures
0-32767 First Come First Served
32768-65535 IETF Review
Type Value Description Reference
0 Administrator field is a two-byte Autonomous System Number [RFC4364]
1 Administrator field is a four-byte IP Address [RFC4364]
2 Administrator field is a four-byte Autonomous System Number [RFC4364]
3-65534 Unassigned
65535 For Use Only in Certain Leaf A-D Routes [RFC7524]