Configuring Token Ring-NET VLAN Characteristics

A Token ring network entity title (NET) VLAN represents a set of ring segments connected by source-route bridges. A Token Ring bridge relay function (TRBRF) VLAN connects multiple Token Ring concentrator relay function (TRCRF) VLANs in a switched Token Ring network. The TRBRF can be extended across a network of switches connected with trunk links. The connection between the TRCRF and the TRBRF is referred to as a logical port. For source routing, the switch appears as a single bridge between the logical rings. The TRBRF can function as a source-route bridge (SRB) or source-route transparent (SRT) bridge running either IBM or IEEE Spanning-Tree Protocol (STP). To accommodate IBM Systems Network Architecture (SNA) traffic, you can use a combination of SRT and SRB modes.

Note: Before you start, review the VLAN configuration rules.

Note: This switch only supports Ethernet interfaces. You configure Token Ring-NET media-specific characteristics only for VLAN Trunk Protocol (VTP) global advertisements to other switches.

To configure Token Ring-NET specific VLAN characteristics:

  1. In the VLAN ID field, enter the number of the Token Ring-NET VLAN.
  2. In the VLAN Name field, enter a VLAN name from 1 to 32 characters that is unique within the administrative domain.
    The default name is "VLANxxxx" where "xxxx" represents four digits (including leading zeros) equal to the VLAN ID number.
  3. Select Token Ring-NET/TRCRF from the VLAN Media Type drop-down list.
  4. In the 802.10 SAID (security association identifier) field, enter a number from 1 to 4294967294 that is unique within the administrative domain.
    The default is 100000 plus the VLAN ID.
  5. In the MTU Size field, enter a number from 1500 to 18190 for the maximum transmission unit (packet size in bytes) that the VLAN can use.
    The default is 1500.
  6. If you are translationally bridging from one VLAN type to another (such as from Token Ring-NET to FDDI), in the Translational Bridge 1 and Translational Bridge 2 fields, enter the VLAN IDs (from 0 to 1005) of the two VLANs to which this VLAN is translationally bridging.
    By default, these fields are set to zero, which means translational bridging is not in effect.
  7. In the VLAN Status drop-down list, select Enabled.
    By default, Suspended is selected. When the status is suspended, all traffic for that VLAN is blocked on all switches in the management domain.
  8. In the Bridge Number field, enter a logical distributed source-route bridge number (from 0 to 15) that interconnects all logical rings having the same parent VLAN.
    By default, this field is set to zero, which means that no source-route bridge is defined.
    Note: To avoid configuration errors when you try to reenable VTP version 2 mode, make sure to specify a bridge number.
  9. From the STP Type drop-down list, select IEEE, IBM, or AUTO.
    The default is IBM for source-route bridging.
    Select IEEE for source-route transparent bridging.
    Select AUTO for a combination of source-route bridging and source-route transparent bridging. Use AUTO only if the VTP V2 mode is enabled.
  10. Click OK to put your changes in effect and close the VLAN Configuration dialog box.
  11. Click OK to close the VTP Management window.