number of vlans in an mst instance

dondejdondej Member Posts: 11 ■□□□□□□□□□
does anyone know how many, or is their a limit to the number of vlans in an mst instance? not mst0 as this has all vlans anyway. The max i've seen configured is 500
The journey of a thousand miles starts with one step

Comments

  • Mrock4Mrock4 Banned Posts: 2,359 ■■■■■■■■□□
    If I'm not mistaken, the max amount of MST instances is 16, with the amount of vlans being mapped to each one unlimited. To be honest though, I can't find any documentation at the moment, so I'd like to see some if somebody has any.
  • Forsaken_GAForsaken_GA Member Posts: 4,024
    I'm pretty sure that the number of vlan's you can map to an instance is only limited by the number of vlans that the switch will support.
  • NetwurkNetwurk Member Posts: 1,155 ■■■■■□□□□□
    I'm pretty sure that the number of vlan's you can map to an instance is only limited by the number of vlans that the switch will support.

    Sounds right to me. If the default instance can accept all VLANs, then adding more instances isn't likely to limit the number of VLANs an instance can handle.

    Good question though, got me thinking

    :)
  • dondejdondej Member Posts: 11 ■□□□□□□□□□
    thanks guys, i'm due to implement an mst config with 6 instances each with 500 vlans mapped to an instance, thought it might be quicker to have just 2 with vlans split between them since i'm only using two distributions switches and will have 2 mst priorities

    instance 1 vlan 100-199, 300-399, 500-599, 700-799, 900-999
    instance 2 vlan 2-99, 200-299, 400-499, 600-699, 800-899
    instance 3 vlan 1100-1199,1300-1399,1500-1599,1700-1799,1900-1999
    instance 4 vlan 1000-1099,1200-1299,1400-1499,1600-1699,1800-1899
    instance 5 vlan 2100-2199,2300-2399,2500-2599,2700-2799,2900-2999
    instance 6 vlan 2000-2099,2200-2299,2400-2499,2600-2699,2800-2899

    spanning-tree mst 0 priority 0
    spanning-tree mst 1 priority 24576
    spanning-tree mst 2 priority 28672
    spanning-tree mst 3 priority 24576
    spanning-tree mst 4 priority 28762
    spanning-tree mst 5 priority 24576
    spanning-tree mst 6 priority 28762
    The journey of a thousand miles starts with one step
  • Mrock4Mrock4 Banned Posts: 2,359 ■■■■■■■■□□
    The only question I'd raise with 6 instances is- will your network be able to fully reap the benefits of having 6 instances (logical topologies) ?? If not, there is not much a difference between those and 2 instances, depending on the physical topology. Especially if those MST instances are going to share the same logical topology.

    Another thing is that although by default all VLANS are mapped to IST, hardly any of those are active on the links. You could load the instance with VLAN mappings but actually having data pass through on that instance is another story.
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