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Disco
Asked: 2012-02-27 01:13:17 +0800 CST

Can't understand how VLAN Tagging, Untagging Works

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I'm trying to setup a 48 ports gigabit switch (netgear GS748T).

My goal is to split the 48 ports to 3 vlans :

  • VLAN10 ports 2-20
  • VLAN20 ports 21-30
  • VLAN30 ports 31-46

What i did is :

  • On VLAN1, TAG port 1, UNTAG every other ports
  • On VLAN10, TAG PORTS 2-20, UNTAG every other ports
  • On VLAN20, TAG PORTS 21-30, UNTAG every other ports
  • On VLAN30, TAG PORTS 31-46, UNTAG every other ports

I didn't touch the PVID configuration page; don't know what this is.

Now, if i plug a cable to port 5, i can ping VLAN20 and VLAN30; same for VLAN20 i can ping VLAN10 and VLAN30.

What am I doing wrong here ? I'm quite new to VLANs ...

edit: VLAN10 is WAN (connected to firewall interface x0, public subnet/26) VLAN20 is MGMT (connected to firewall interface x4, 10.0.0.x/24)

Whenever i plug from firewall to vlan20 i see all ports of the switch go crazy and i have packet loss when pinging switch or accessing his web ui.

networking vlan

1 Answers

  1. Best Answer

    do you want to have any trunk-port [port that combines more than one vlan] or do you just want to have total traffic separation for three groups?

    if the second - i suggest you:

    • leave port 1 as it is for experimentation
    • set up vlan10 - port 2-20 untagged, all other ports blank [not member]
    • set up vlan20 - ports 21-30 untagged, all other ports blank [not member]
    • set up vlan30 - ports 31-46 untagged, all other ports blank [not member]
    • 5