interface configuration command or the set vlan 12 name crf12 type trcrf ring 0x12 parent 100 interface
configuration command.
When defining a corresponding LEC, you could enter name crf12 local-seg-id 0x12 or name crf12 local-
seg-id 18 because 18 is the decimal equivalent of 0x12.
•
Before you can create a LEC, the TrBRF and TrCRF to which it will be associated must exist.
•
Do not create more than one LEC for each TrBRF per ATM module.
While you can have only one LEC per TrBRF per module, you can have more than one module installed.
This allows you to have more than one LEC per TrBRF, which means the switch can participate in more
than one ELAN. The ELANs, however, cannot be parallel or the Spanning-Tree Protocol will block one of
the connections.
Note
Configuring more than one LEC for a TrBRF on a single ATM module will adversely affect frame
forwarding.
•
Ensure that all-routes explorer (ARE) reduction is enabled (using the set tokenring reduction enable
interface configuration command) on the Token Ring module.
•
Do not configure parallel ELANs within a TrBRF (parallel ELANs are those ELANs that form a loop
between switches).
•
Do not create more than one LEC for each TrCRF per ATM module.
A TrCRF can include only one enabled LEC from any ATM module.
An ATM module LEC is assigned to a TrCRF to provide connectivity to the ATM network. In this sense,
an ATM module is a logical port within the TrCRF. When assigning enabled LECs to TrCRFs, the enabled
LECs of any one ATM expansion module should each be assigned to different TrCRFs.
•
You can change all ELAN names with the exception of VLANs 1, 1003, or 1005 whose ELAN names
must remain default, trcrf-default, and trbrf-default, respectively. You cannot override the ELAN
name for VLAN 1, 1003, or 1005 by using the name elan_name parameter. You can assign all other
VLANs any name.
When you enter the set vlan vlan_num [ name vlan_name ] interface configuration command in transparent
mode and do not specify the optional name elan_name parameter, the software uses the names in the table
below by default.
Table 2
Default VLAN ELAN Names
VLAN Number
VLAN Name
1
default
2...1002
VLAN0002 through VLAN1002
1003
trcrf-default
1004
VLAN1004
1005
trbrf-default
If you currently have a different ELAN name for VLAN 1 or VLAN 1003, you must change the ELAN
name to default (for VLAN 1) or trcrf-default (for VLAN 1003) in the LECS database. The following
Setting Up a LES BUS and a LEC
Guidelines for Setting Up a LEC
20
