Is it possible to configure trunking between a NetGear Switch and a Cisco Router?

Question

Hardware:

Cisco 2921 Router

Netgear GS752TXS Switch. Tags data with either Vlan1 (192.168.1.0/24) or Vlan2 (192.168.2.0/24) depending on mac address.

I want the cisco router to perform inter-vlan routing. The switch and the router will be connected with one cable on one interface.

I created sub-interfaces for the two VLANs on the router (Gi0/0.1) and (Gi0/0.2) and enabled dot1q encapsulation.

On the switch side if it were cisco, I would do:

interface gi0/0

switchport trunk encapsulation dot1q

switchport mode trunk

How do I do this on a netgear switch?

Solution

i'm not very familiar with netgear devices. the config seems do be similar to HP Switches. You had to set the Interfaces Tagged or Untagged for the VLAN IDs. Example Port1 is connected to the Router:

• set vlan1 UNTAGGED on Port 1 (it's the native Vlan; dot1q Frames are send in the native Vlan)
• set all other Vlans you want to transport on this interface TAGGED on Port1

This is different to Cisco Trunks you had to specify each VLan you want to transport on the Trunk Link. I configured a few Trunks between Cisco and HP and this is the way how it works.

Have a look at:

http://documentation.netgear.com/gs108t/enu/202-10337-01/GS108T_UM-10-3.html

Comments

[Copy Run Start]

Thank you for replying. Hmm I'm not sure what you mean. The switch is already tagging the data with the proper VLAN's. What I'm wondering is how I change the interface on the netgear switch that will connect to the router to a trunk port. (Or if that's even necessary). I will have a very brief window to test this so I want to get the config right before I do it.

[NickW]

If you tag multiple vlans on a port it will effectively create a trunk if the port on the opposite side is also tagging the same vlans.

[user1008764]

a little more detail in my answer now

[JamesRyan]

cisco and netgear have different meanings for the term trunk. For netgear it means port aggregation, cisco it means tagged for all vlans

[Copy Run Start]

@JamesRyan This is exactly why I'm confused. The manual refers to trunking but it's really aggregation. User1008764: When you say "this is different to cisco trunks you had to specify each Vlans you want to transport on the Trunk Link" I don't know what you mean. On the cisco switch I just enable trunking and encapsulation. No need to specify the VLANs it will be passing. NickW: So you're saying as long as I tag multiple VLANs on the netgear's interface, it will work?

[user1008764]

configuring a Trunk Port on Cisco Devices means that all Frames going out that Interface are encapsulated with a dot1q Header and are transported via the Native VLan. Per default the native VLan is VLan 1. The VLAN ID of the original Frame is "tagged" within the dot1q Header. All VLans are transported via this Trunk and there is nothing else to do. If your Native VLan is not VLan 1 you had to specify the Native VLan Id in the Trunk configuraion.

[user1008764]

too long comment. so here we continue: On Netgear and HP Switches you always had to specify the Native VLAN with the untagged command -> Vlan 1 untagged port1. And there is a second step to do. You had to specify which VLans should use this Link -> vlan 2 tagged Port 1, vlan 3 tagged port 1,...

[user1008764]

yes on the netgear switch set the trunk port untagged for vlan1. that's all.