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SecurityPlus
Explorer III
Jun 10, 2020 2:20 PM UTC
Solved

Inter-switch link (ISL) - Bandwidth

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?

    ede_pfau
    ede_pfauAnswer
    SuperUser
    Jun 12, 2020 7:38 PM UTC

    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.

    4 replies

    SecurityPlus
    Explorer III
    Jun 12, 2020 6:13 AM UTC

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

    tanr
    New Member
    Jun 12, 2020 3:30 PM UTC

    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
    SuperUser
    ede_pfauAnswer
    SuperUser
    Jun 12, 2020 7:38 PM UTC

    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.

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