VLAN numbering

Jump to: Scheme details, VLANs 1-999, VLANs 1000-4094

VLANs using IEEE 802.1Q are given tags/IDs between 1 and 4094.  These tags can be used on links between the University Data Network (UDN - the University backbone network) and institutional networks and must match at both ends.

Care must be taken by network administrators to ensure that the IDs used for purely internal networks within their institutions (or the UDN itself), that do not need to pass across these links, do not clash with numbers which may be used for VLANs between networks (in particular, the UDN and an institution).

Whilst the distinction is only important if an institutional network is importing or exporting a VLAN, institutions should bear in mind that even if they have no intention of importing or exporting VLANs now, that may change in future.  Institutions are therefore recommended to allocate VLAN numbers based on the scheme to avoid future renumbering problems.

Scheme details

Ranges of numbers are allocated for different purposes:

The tables below show which numbers are allocated to each of these categories.

VLANs 1-999

For tags in the form x | yz (1-999), a fairly complex scheme is used due to historical developments and configurations in place, prior to it being determined:

VLANs 1000-4094

For VLAN numbers of 1000 and above, a much simpler scheme is in use:

Last updated: 11th July 2024