To avoid writing out very repetitive (and long) OIDs this appendix uses a substitution notation when describing structures. The OIDs contain the names of indices and an X representing the structure field number given by the matching column in the following table. So if the OID given in the manual is iso.1.2.3.4.X.anIndex then the OID for the first item described in the table row with column X = 3 would be: iso.1.2.3.4.3.1

I.1.1. IP addresses as indices

In some structures IP addresses may be used as indices into SNMP tables. When this is the case the IP must be encoded into the OID for the resource. This encoding consists of the following separated by dots:

The IP type: 1 for IPv4, 2 for IPv6.
A length prefixed array of the bytes of the address in network order.

Example I.1.

For the IPv4 address 10.0.1.12 the IP type is 1 and the length is 4. Therefore the OID fragment 1.4.10.0.1.12 could be used as an index.

Example I.2.

For the IPv6 address 2001::32 the IP type is 2 and the length is 16. Therefore the OID fragment 2.16.32.1.0.0.0.0.0.0.0.0.0.0.0.0.0.50 could be used as an index.


H.7. Change of Authorisation		I.2. Firebrick-specific structures for BGP