Category: VLANs

IP helper

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We all are familiar with the IP helper command to allow DHCP requests (broadcast) passthrough a router to get as a unicast packet to a DHCP server. Pretty easy and simple.. But the IP helper can do more!
When there is a network with multiple vlans and you need the use the good old “net send” command from Windows computers on all computers on all the VLAN’s, you have to configure the IP helper.
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Private VLANs

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Private VLAN configuration could be tricky:
A Private VLAN environment consist of a few VLANs:

  • Primary VLAN
  • Secondary VLAN
    • Community VLAN
    • Isolated VLAN

Every Secondary VLAN will be associated to a primary VLAN. Every primary VLAN can exist of multiple community VLANs but only 1 isolated VLAN.
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