Configuring interswitch link (ISL) ports (PVLAN member ports)

To configure an interswitch link, you must change the configuration of an existing promiscuous port or trunk group in the primary VLAN on each of the two switches in the link.

Prerequisites

The primary VLAN must exist in the configuration.
You must be in the global configuration context: switch(config)#

Procedure

To configure a single port as an interswitch link (PVLAN member port):
1. Choose the port to be used for the interswitch link and remove the existing (default) promiscuous port configuration setting for that interface.
  For example:
```
switch-A(config)# no interface 1/A3 private-vlan promiscuous
```
To configure a port trunk group as an interswitch link (PVLAN member):
1. Choose the trunk group to be used for the interswitch link and remove the existing (default) promiscuous port configuration setting for that interface.
  For example:
```
switch-A(config)# no interface trk1 private-vlan promiscuous
```

Adding an interswitch link between two switches for VLAN 300

The interface you choose on the second switch does not have to match the interface you choose on the first switch.

Switch A commands:

switch-A(config)# vlan 300 tagged 1/A3
switch-A(config)# no interface 1/A3 private-vlan promiscous

Switch B commands:

switch-B(config)# vlan 300 tagged 1/A3
switch-B(config)# no interface 1/A3 private-vlan promiscous

You can also configure port trunk groups as an interswitch link. You can use either a static trunk or a static LACP trunk.

This example shows configuring a trunk group, adding the trunk group to the PVLAN as a tagged interface, and then configuring that trunk group as an interswitch link.

IMPORTANT:

Configure port trunking before you connect the trunked links between switches. Otherwise, a broadcast storm could occur. (If you want to connect the ports before configuring them for trunking, you can temporarily disable the ports until the trunk is configured.) For more information about port trunking, see the ArubaOS-Switch Management and Configuration Guide.

switch-A(config)# switch-A(config)# trunk 1/A3,1/A4 trk1 lacp
switch-A(config)# vlan 300 tagged trk1
switch-A(config)# no interface trk1 private-vlan promiscous