Authorization VLAN

The device uses the authorization VLAN to control the access of an 802.1X user to authorized network resources.

Supported VLAN types and forms

Support for VLAN types and forms depends on the authorization type.


[NOTE: ]

NOTE:

The access device converts VLAN names and VLAN group name into VLAN IDs before VLAN assignment.


Unsupported VLAN types

Do not specify the following types of VLANs for VLAN authorization. The access device does not assign these VLANs to 802.1X users.

VLAN selection and assignment

If the server assigns a group of VLANs, the access device selects and assigns a VLAN according to the VLAN ID format. Table 5 describes the VLAN selection and assignment rules for a group of authorization VLANs.

Table 6: VLAN selection and assignment for a group of authorization VLANs

Types of authorized VLANs

VLAN selection and assignment rules

  • VLANs by IDs

  • VLANs by names

  • VLAN group name

The device selects a VLAN as the authorization VLAN for a user, depending on whether the port has other online users:

  • If the port does not have other online users, the device selects the VLAN with the lowest ID from the group of VLANs.

  • If the port has other online users, the device selects the VLAN by using the following process:

    1. The device selects the VLAN that has the fewest number of online users.

    2. If two VLANs have the same number of online 802.1X users, the device selects the VLAN with the lower ID.

The device follows the rules in Table 6 to handle VLAN assignment.

VLAN IDs with suffixes

  1. The device selects the leftmost VLAN ID without a suffix, or the leftmost VLAN ID suffixed by u as an untagged VLAN, whichever is more leftmost.

  2. The device assigns the untagged VLAN to the port as the PVID, and it assigns the remaining as tagged VLANs. If no untagged VLAN is assigned, the PVID of the port does not change. The port permits traffic from these tagged and untagged VLANs to pass through.

For example, the authentication server sends the string 1u 2t 3 to the access device for a user. The device assigns VLAN 1 as an untagged VLAN and other VLANs as tagged VLANs. VLAN 1 becomes the PVID.


[NOTE: ]

NOTE:

Assign VLAN IDs with suffixes only to hybrid or trunk ports that perform port-based access control.


Table 6 describes how the access device handles VLANs (except for the VLANs specified with suffixes) on an 802.1X-enabled port.

Table 7: VLAN manipulation

Port access control method

VLAN manipulation

Port-based

The device assigns the port to the first authenticated user's authorization VLAN. All subsequent 802.1X users can access the VLAN without authentication.

If the port is assigned to the authorization VLAN as an untagged member, the authorization VLAN becomes the PVID. If the port is assigned to the authorization VLAN as a tagged member, the PVID of the port does not change.

MAC-based

  • For a hybrid port with MAC-based VLAN enabled, the device maps the MAC address of each user to its own authorization VLAN. The PVID of the port does not change.

  • For an access, trunk, or MAC-based VLAN-disabled hybrid port:

    • If the port is assigned to the authorization VLAN as an untagged member, the device assigns the port to the first authenticated user's authorization VLAN. The authorization VLAN becomes the PVID. To ensure successful authentication of subsequent users, authorize the same VLAN to all 802.1X users on the port. If a different VLAN is authorized to a subsequent user, the user cannot pass the authentication.

    • If the port is assigned to the authorization VLAN as a tagged member, the PVID of the port does not change. The device maps the MAC address of each user to its own authorization VLAN.


[IMPORTANT: ]

IMPORTANT:

  • An 802.1X-enabled access port can be assigned to an authorization VLAN only as an untagged member.

  • 802.1X support for tagged VLAN assignment is available in Release 1121 and later.


  • A hybrid port is always assigned to a VLAN as an untagged member. After the assignment, do not reconfigure the port as a tagged member in the VLAN.

    On a port enabled with periodic online user reauthentication, the MAC-based VLAN feature does not take effect on a user who has been online before this feature was enabled. The access device creates a MAC-to-VLAN mapping for the user when the following requirements are met:

    For more information about VLAN configuration and MAC-based VLANs, see Layer 2—LAN Switching Configuration Guide.