VLAN in 1841

[Bikas Giri]

Hi,

I have got a cisco 1841 router. I am able to create different vlan in the cisco router and I have got only 2 ports, fa0/0 and fa0/1. Now, I need to create different network in the same router at least four networks. FA0/0 is used for external networks. Now I want to create 4 vlan in this router. Namely, 10.10.10.1, 10.10.11.1, 10.10.12.1 and 10.10.13.1. The FA0/1 is connected to a 48 port normal switch. In the switch I am going to connect the cable of all the 10.10..... networks. Is this possible to access creating four vlan and routing all of them to the external networks with the fa0/1 port only. Is dot1q possible with only the router and a normal switch or is there any other possibility for this case.

Thanks in advance

Bikas Giri

[Edison Ortiz]

You can certainly route the Vlans you've created internally on the 1841. You can use an IGP such as EIGRP or OSPF or static routing.

If you want the switch to have multiple Vlans representing the 10.x, 11.x, 12.x, 13.x network and the switch is running Layer2, you need to trunk the interface between the 1841 and the switch. The 1841 will perform the inter-vlan routing for those Vlans.

Regards,

Edison

[Fabio Francisco]

Hey Bikas,

Edison precisely explained how to have the vlan set up on your router.

Further to that you need create subinterfaces for each network. like this

FA0/0.10 for vlan 10

encapsulation dot1q 10

and so on....

This doco will give you a heads up http://www.cisco.com/en/US/tech/tk389/tk815/technologies_configuration_example09186a00800949fd.shtml

Cheers,

Fabio

[Bikas Giri]

Dear Edison/Fabio,

I don't have got the catalyst switch, I only have got the normal switch and I won't be able to send a trunk through non-manageable switch. In this condition could you please suggest me any idea so that I can generate all the four network in the port fa0/1 only with 1841 router and a non-manageable switch.

Regards,

Bikas

[Edison Ortiz]

If you have a dumb switch, you won't be able to create multiple Vlans in it. Devices on that switch can only reside on one Vlan and creating multiple Vlans on the 1841 won't provide you any benefit.

[Fabio Francisco · Accepted solution]

buy a catalyst switch. a 2950 is very cheap thesedays...