Network & Telephone Services
VLAN number allocation within the CUDN
For VLAN numbers of the form xyz (1-999):
| x \ yz | x00 | x01 | x02-x09 | x10-x79 | x80-x89 | x90-x99 |
|---|---|---|---|---|---|---|
| 0yz | n/a | Local | Global | Global | Global | Global |
| 1yz | Local | Local | Local | Global | Reserved | Local |
| 2yz | Reserved | Reserved | Reserved | Global | Reserved | Local |
| 3yz | Reserved | Reserved | Reserved | Global | Reserved | Local |
| 4yz | Reserved | Reserved | Reserved | Global | Reserved | Local |
| 5yz | Reserved | Reserved | Reserved | Global | Reserved | Local |
| 6yz | Reserved | Reserved | Reserved | Global | Reserved | Local |
| 7yz | Reserved | Reserved | Reserved | Global | Reserved | Local |
| 8yz | Reserved | Reserved | Reserved | Global | Reserved | Local |
| 9yz | Reserved | Reserved | Reserved | Global | Reserved | Local |
For VLAN numbers of 1000 and above:
| 1000-1999 | Local |
| 2000-3999 | Global |
| 4000-4094 | Local |
where
| Reserved | indicates that VLANs numbered in that range are reserved at the present time and must not be used. |
| Global | indicates that VLANs numbered in that range are allocated by the Computing Service for global use across the CUDN; institutions must not allocate these numbers to their own VLANs. |
| Local | indicates that VLANs in that numbered range can be allocated for use within and by an institution without danger of clashing with numbers used by VLANs used globally across the CUDN. |
The distinction is only important if an institutional network is importing or exporting a VLAN; however, 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 above scheme to avoid future renumbering problems.