2 Vlans Talking to each other

brosspntr · ‎02-05-2002

I am rookie when it comes to vlans so please keep this in mind.

What I am trying to accomplish is we have a 10.16.0.0/16 network.

I want to create 2 vlans (to seperate traffic)

like have 10.16.1.1-20 on 1 vlan and 10.16.1.21-40 on another, can I do this and have them talk to each other and accomplish seperate broadcast domains with the vlan?

Thanks again

r-godden · ‎02-06-2002

if you use vlans then you will need to route between

them.

for 20 hosts per vlan use 27 bit mask 255.255.255.224 this will divide your addresses into

0-31 32-63 etc

brosspntr · ‎02-06-2002

So I have to put a router in between them? Can I use 1 interface with a primary and secondary address?

ejgonzalesiii · ‎02-06-2002

Yes this will work only if the router that you are using supports trunking.

-Henry

a.greaves · ‎02-08-2002

Hi,

I noticed your conversation and in response I would like to ask if a Cisco 2500 running 11.2 os supports trunking?

Regards

Adrian

mailto : adrian@shortwave-it.co.uk

paquino · ‎02-08-2002

Ok

1. It seems like the 10.16.1.1-20 and the 10.16.1.21-40 fall within the same 255.255.0.0 IP subnet. In this case saparating these ip addresses with a vlan would totally isolate isolate the machines from one another.

vlan 1 10 .16 .1. 1-20

vlan 2 10 .16 .1. 21-40

255.255.0. 0

these are the same ip subnet.

2. If you meant the subnet 10.16.0.1-20 and

10.17.0.1-20 then they would be seperate broadcast domains but unable to talk to one another without a layer 3 interface for routing. So the answer is no you still wouldnt have full connectivity.

Lemme know if this helps

Sincerely,

Paul Aquino

CSE

Cisco Systems

ryan.vaughn · ‎02-11-2002

I have done something similar to this, but not exactly what you are looking at.

I use Bay Networks Baystack 350T switches to seperate my vlans behind the router. Normally, I only vlan seperate subnets, but it should also work for vlans inside a subnet. We use this to run a single line into a building and seperate the tenant traffic via vlans to a single interface on a cisco router. I have never gotten a cisco catalyst switch to do the same thing I have seen with Baystack switches. I am not sure if this is because of functionality or inexperience on my part with catalyst switches (probably the latter of the two.)

I would NOT recommend taking this path however. If you want to seperate the 2 networks, I would recommend routing the two segments of the network between two interfaces on a router in two seperate networks. I just believe in presenting all options ;c)