VLAN Tagging on Trunk

[Aulakhl]

Question:-
When we create Trunk between two procurve switches and we need to Tag vlans on that trunk to extend Vlan to another switch, do we have to assign a ip adress to Vlan on both switches or just only one switch.?

[Aulakhl]

I had two layer 3 Procurve switches and they are connected via trunk and i want to extend vlans on Switch A to Switch B, Switch A had all Vlans assigned IP address and if i extend those Vlans to Switch B via Trunk do i need to assign same IP adress on Vlans on Switch B also or not.?

[luckyh]

A Layer-3 Instance has nothing to do with a Layer-2 vlan. you do not need an SVI. You just have to ensure that the vlans exists on both switches, either manually create them on your second switch or use GVRP to distribute your VLANS across your switches. Ensure also that the interface for interconnection is transmitting the vlan.

ex. switch A 4 ports prepared as uplink trunk to interconnect other switches via port 21-24

vlan 11
   name "marketing"
   tagged 21-24
   exit
vlan 12
   name "supp"
   tagged 21-24
   exit
vlan 13
   name "WLAN"
   tagged 21-24

[TerjeAFK]

You only need an IP address for the Vlans if you are going to do L3 stuff like routing or DHCP server/relay.

[Aulakhl]

Yes inam going to do a L3 Stuff and routing, and i want to extend vlans from a switch A to Seitch B, i created Vlans with same id on Switch B and had a 2 port trunk between 2 switches, Vlans on Switch A had ip address assigned, do i have to assign Ip on vlans on switch B or not.?

[luckyh · Accepted solution]

NO

you do not have to...

your traffic is switched and transported in Layer-2, if you only want to "leave" your vlan on side-A (route) thats fine.

If you a speaking of 2-port trunk than that is link-aggregation via static or LACP (802.3ad) as long as you have on both sides

vlan A
    tagged trk<X>
    exit
vlan B
    tagged trk <x>
...
...
vlan N
    tagged trk<X>

sending all your needed vlans into the trunk

The term trunk is different interpreted between vendors some mean with it an 802.1q trunk (vlan tagging)

others refer to is as 802.3ad trunk (link aggregation of ports) either static or with the LACProtocol