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vlan tagging

Occasional Advisor

vlan tagging

Hi friends,  I have a scenario. in which there are three switches . 1 hp 5406zl and two HP 2920 switches.

Switch A (5406z,routing enabled) vlans in this switch are vlan 10(svi ->, vlan 20(, vlan 30(

Tagged ports

(b1 -> switch B)

(b2->switch C)

In Switch B (Vlans are 10 and 20)  Tagged port 45 ->b1

In Switch C (Vlan 30 only)  Tagged port 45->b2

My question is that what all vlans should be tagged on ports of the switches to get communicaton between vlan 10 and 30 and also  with vlan 20

In switch A

is it necessary to tag vlan 10, 20 and 30 on port b1 going to switch B



Honored Contributor

Re: vlan tagging

If the Switch A already correctly routes all defined VLANs (VLAN 10, 20 and 30) you just need to permit all those VLANs on both your two Switches uplinks (Uplink 1: Switch A Port B1 <--> Switch B Port 45 and Uplink 2: Switch A Port B2 <--> Switch C Port 45) so tagged traffic that belongs to VLANs 10 and 20 will be permitted between Switch B and C through Switch A by means of its two uplinks.

The same for tagged traffic that belongs to VLAN 30, it will permitted between Switch C and B always through Switch A by means of its two uplinks.

That way all VLANs speak with all VLANs through routing Switch A.

Basically you should permit involved VLANs on each involved ports (Ports B1 and B2 on Switch A, Port 45 on Switch B and Port 45 on Switch C).

I actually suppose your involved ports are yet of Type Trunk and yet permit actually (and respectively) only VLANs 10 and 20 on Switch A <--> B uplink and only VLAN 30 on Switch A <--> C uplink...this to say that, actually, VLANs traffic flows correctly between Switch B and A, from Switch C and A but not between Switch B and C through Switch C.