Inter-switch link (ISL) - Bandwidth

[SecurityPlus]

Trying to learn more about the FortiSwitch. I see that when using multiple FortiSwitch switches it is common to use ISL between the switches. Will this restrict connection speed between switches? In other words what bandwidth does this ISL support?

[tanr · Accepted solution]

For FortiLink/ISL adding multiple connections between the switches automagically gives you an aggregate.  At least that's what I've been doing on 6.0.

If you're trying to set up with redundancy or MCLAG it might be different.

[SecurityPlus]

In other words, is the ISL connection limited to 1 GB on a 1 GB switch? If so this could create a bottleneck.

[tanr · Accepted solution]

For FortiLink/ISL adding multiple connections between the switches automagically gives you an aggregate.  At least that's what I've been doing on 6.0.

If you're trying to set up with redundancy or MCLAG it might be different.

[ede_pfau · Accepted solution]

I've noticed that a FortiLink internally is built by an aggregate link. So it's quite easy to increase the bandwidth. Same might be the case with ISLs.

[SecurityPlus]

tanr & ede_pfau, Thanks