User Manual

116 Administering ISL trunking
• Use the portperfshow command as described in the following procedure to record traffic volume
for each port in your fabric over time.
To use the portperfshow command:
1. Connect to the switch and log in as admin.
2. Issue the following command:
portperfshow [interval]
where interval is the number of seconds between each data-gathering sample (the default is one
sample every second).
3. Record the traffic flow for each port participating in an ISL.
4. Repeat step 1 through step 3 for each switch in the fabric until all ISL traffic flow is captured.
In a large fabric, it may be necessary to only identify and capture the key ISLs. However, you may
want to continue this process throughout the day (or an entire work cycle), to capture varying traffic
patterns under different conditions.
The following example shows a switch without trunking, and indicates that ports 0 through 2 are
underutilized and ports 4 and 5 are congested:
The following example shows traffic flowing through a trunking group (ports 5, 6, and 7). After port 6
fails, traffic is redistributed over the remaining two links in the group, ports 5 and 7:
Enabling and disabling ISL trunking
You can enable or disable ISL Trunking for one port or for an entire switch. To enable or disable ISL
Trunking on one port:
1. Connect to the switch and log in as admin.
switch:admin> portperfshow
01234567 Total
--------------------------------------------------------------------
000145m204m202m0168m 719
000145m206m208m0186m 745
switch:admin>
switch:admin> portperfshow
01234567 Total
--------------------------------------------------------------------
00000145m144m145m 434
00000144m143m144m 431
00000162m0162m 324
00000186m0186m 372
00000193m0192m 385
00000202m0202m 404
00000209m0209m 418
switch:admin>