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New Member

Routing CobraNet through a 3750 switch

Dear Cisco Users.

I'm working with a professional audio product that uses a 3rd party audio transport protocol called CobraNet ( of which is transmitted on standard ethernet hardware. CobraNet is based at the MAC address layer and therefore does not have an IP address within the packet header to define source and destination location, instead it uses the MAC address. Because of this CobraNet requires a Layer 2 switch rather than a Layer 3 device to forward packets between nodes within a LAN.

I'm working on a project that is specified with the Cisco 3750 range and after reading the spec sheet it states multi-layer rather than a specific layer. My question is this….. Will the 3750 switch support / forward CobraNet packets in its default configuration, will it have to be configured (and of so how) or do I need to request a different Cisco range to be used?

Thank you in advance for any comments and suggestions.

NB: - Please note; I'm not an ethernet guru so simple wording is preferred.


Cisco Employee

Re: Routing CobraNet through a 3750 switch

Hi Jay,

Not exactly sure how this cobranet work but as you mentioned it works on ethernet and mac layer it should wokr on 3750 switch.

3750 is a layer 3 switch but also works as layer 2. By default ip routing is disable on the same and all ports are configured for dynamic desirable mode.

If you want you can configure them for acces mode and whatever vlan you want by default it is vlan 1. Attach your devices to these ports and it should work. Do not get confuse with the term multi-layer, this switch can work as normal layer 2 switch also.



*Pls rate all helpfull post

New Member

Re: Routing CobraNet through a 3750 switch

A configuration that may help was already commented below, but to expound on it the following may be helpful.

Cisco switches allow you to have multiple vlans, the configuration of it would look like the following if you did a show running command:

Interface FastEthernet0/1

switchport access vlan 260

switchport mode access

The vlan number is unimportant in the discussion because you can set it to any value you wish, except for vlan 1 which is the "default" vlan in the configuration. All devices will be able to talk at the layer 2 level if you use the default vlan, but if you are trying to have different layer 3 subnets talk to each other on top of having cobranet devices connected to those different layer 3 subnets, you'll want to use multiple vlans.

A vlan creates a broadcast domain among different devices. All devices you assign to the same vlan will be able to talk at the layer 2 level, and any devices you assign an ip address in the same subnet will be able to talk to those devices as well.

Do you have a test setup or perhaps an idea of how the final network will be setup? Will there be servers on different subnets?

New Member

Re: Routing CobraNet through a 3750 switch

Thank you for your prompt response….. So in brief; out of the box the 3750 switch is setup as a layer 2 switch but can be configured for more advanced routing / separation etc…. ?

New Member

Re: Routing CobraNet through a 3750 switch

Exactly. Talking with some of the local engineers here I have gotten some more specific information which I will forward to you off list.

At this point it sounds like you should be able to just "plug and play".

Cisco Employee

Re: Routing CobraNet through a 3750 switch

Hi Justin,

You got it right!!



New Member

Re: Routing CobraNet through a 3750 switch

Thank you all.... I'll leave this session open until I get confirmation from my end user that all is sweet!