Administrator Guide

576 Fabric OS Administrator’s Guide
53-1002920-02
Trunk Area and Admin Domains
24
Trunk Area and Admin Domains
Ports from different Admin Domains (ADs) are not allowed to join the same Trunk Area (TA) group.
The portTrunkArea command prevents the different ADs from joining the TA group.
When you assign a TA, the ports within the TA group have the same index. The index that was
assigned to the ports is no longer part of the switch. Any domain,index (D,I) AD that was assumed
to be part of the domain may no longer exist for that domain because it was removed from the
switch.
Example of Trunk Area assignment on port domain,index
If you have AD1: 3,8; 3,9; 4,13; 4,14 and AD2: 3,10; 3,11, and then create a TA with index 8 with
ports that have index 8, 9, 10, and 11, then index 9, 10, and 11 are no longer with domain 3. This
means that AD2 does not have access to any ports because index 10 and 11 no longer exist on
domain 3. This also means that AD1 no longer has 3,9 in effect, because index 9 no longer exists
for domain 3. Port 3,8, which is the TA group, can still be seen by AD1 along with 4,13 and 4,14.
If a port within a TA is removed, the index is added back to the switch. For example, the same AD1
and AD2 with TA 8 holds true. If you remove port 9 from the TA, it adds index 9 back to the switch.
That means port 3,9 can be seen by AD1 along with 3,8, 4,13, and 4,14.
ISL trunking over long-distance fabrics
In long-distance fabrics, if a port speed is set to autonegotiate, then the maximum speed, which is
16 Gbps, is assumed for reserving buffers for the port. If the port is running at only 2 Gbps, this
wastes buffers. For long-distance ports, you should specify the port speed instead of setting it to
autonegotiate.
In addition to the criteria listed in “Supported configurations for trunking” on page 571, observe the
following criteria for trunking over long-distance fabrics:
• Trunking over long-distance fabrics is supported only on switches running Fabric OS v6.1.0 and
later.
• Extended Fabrics and Trunking licenses are required on all participating switches.
• When configuring long distance, you must configure the portCfgLongDistance
--vc_translation_link_init parameter to be the same on all ports in a long-distance fabric.
For additional information on configuring long distance, refer to “Configuring an extended ISL” on
page 589.
Table 90 summarizes support for trunking over long distance for the Brocade DCX and DCX 8510
Backbones and supported blades.
TABLE 90 Trunking over long distance for the Brocade Backbones and blades
Long-distance mode Distance Number of 2-Gbps ports Number of 4-Gbps ports
LE 10 km 48 (six 8-port trunks) 48 (six 8-port trunks)
L0 Normal See note below 48 (six 8-port trunks)
LD 200 km 4 (one 2-port trunk per switch) 0
LD 250 km 4 (one 2-port trunk per switch) 0