Cat 3750 Subinterface

[jamie.gleeson]

Hello, I am trying to configure a subinterface such as g1/0/1.1 for example but the IOS is indicating "Invalid input detected". Does the 3750 series not support subinterfaces.

The switch model is WS-C3750-48PS-E with IOS version c3750-ipservices-mz.122.46-SE.

The parent interface configuration is as follows:

interface GigabitEthernet1/0/1

no switchport

no ip address

no cdp enable

Any help appreciated.

Jamie

[Thotsaphon Lueangwattanaphong]

Jamie,

Excerpt from C3750 configuration guide 12.2(50)SE(The lastest one,I can find).

###################

Routed Ports

A routed port is a physical port that acts like a port on a router; it does not have to be connected to a router. A routed port is not associated with a particular VLAN, as is an access port. A routed port behaves like a regular router interface, except that it does not support VLAN subinterfaces. Routed ports can be configured with a Layer 3 routing protocol. A routed port is a Layer 3 interface only and does not support Layer 2 protocols, such as DTP and STP.

###################

HTH,

Toshi

[sudheesh.pb]

Jamie,

As toshi suggested it will not work, but if your aim is to give another IP address to this interface, you can configure secondry IP address.

[glen.grant]

If the idea is to trunk more than 1 vlan then you create your layer 3 SVI and put the ip addresses under that and just trunk the layer 2 vlans across that link

int vlan 2

ip address 192.168.2.254 255.255.255.0

int vlan 3

ip address 192.168.3.254 255.255.255.0

int g1/0/1

switch mode trunk

switch trunk encapsulation dot1q

switchport trunk native vlan 2

switchport trunk allowed vlan 2,3

[Alvaro Garcia]

I think that the question is why do you need to configure the subinterface? Is it for InterVLAN Routing?

You can configure that ports as trunk and then create Interface VLANs.

[kishan1984]

3750 switches doesn't support sub-interfaces,create SVI,if you want to make inter-vlan routing.