HELP Needed ! Cisco 1941 router - Internet / LAN issue

[mondeospares]

We have just had a dedictaed BT internet line installed with a cisco 1941 router and I am unable to access the internet through it on the LAN.

The internet is on the ip address 195.99.200.169 - 174.

Our LAN is on 192.168.1.1 - 254

The only way I can get internet access on 4 computers is by manually configuring them to the ip address 195.99.200.170 - 174.

default gateway is 195.99.200.169.

The problem is if I manually configure the computers to this IP address I can;t access anything on our network like NAS storage, printers etc and I can only get 4 computers to work with the internet instead of all 10 that we have currently.

Also this is causing ip address conflicts with our IP phones on the network 192.168.1.1 - 254

The telephone system BT (BCM50) is on the ip address 192.168.1.2

How do I get the router to assign ip addresses to everything on the network 192.168.1.1 - 254 and also get the computers to have internet access on this ip address range?

Any help would be greatly appreciated as BT are not giving me much assistance.

I have created a network diagram to assist,

[John Blakley]

Do you have a dhcp server? Do you have nat configured on the router? Can you post your config?

HTH,
John

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[mondeospares]

We moved location recently and BT installed the line and router before the rest of the network was moved to the new location so I don't know what they configured an what they didn't.

I am unable to tell you the config, i've never used a cisco router before so I've only just found out how you actaully connect to one the other day (my cables are on order (DB9 etc)).

We don't have a DHCP sever, can we enable the router to do this job? Also not sure about NAT.

I know this is not much help to you at the moment, if you can point me in the right direction of what I would need to configure within the router to enable it to assign ip addresses to the LAN (192.168 etc ) and enable the network to use the internet that would be greatly appreciated.

When I have contacted BT about this all they tell me is the router is working becuase they have ping'd it... not helpful

[John Blakley]

Yeah, the telco won't help much if they can see their side. Everything you need can be configured on the router. Do you have someone that knows a little more about Cisco equipment that can help? I could give you the lines that you need to put in the router, but it could take a long time to get through this through a public forum.

Here's what I gather. If you can put yourself on the public address, you're not using nat and quite possibly the inside interface is addressed on the same subnet as your public block which means you'll need something else to do nat for you. The 195.99.200.169 address is probably assigned to your inside interface and that would explain why you can get on the internet.

Is the BT router/modem connected to the Cisco router right now?

HTH,
John

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[mondeospares]

Because we have 4 IDSN2 lines giving 8 phone lines I think the intenet is somehow routed through them as theres 8 connections / lines from 8 sockets on the wall that feed into one white box.  This box is then connected to the cisco 1941 via an ethernet cable. (this is seperate to our phone system).

I'm all the company has in terms of IT support i'm afraid.  I have a bit of knowledge of programming and general computers etc.

How do I utilise NAT?

[John Blakley]

I would recommend you find someone local that has experience in this. Can you hire someone? If not, we'll need to see your config because otherwise it's a lot of guesswork. Console into the device (with your db9 cable) and type:

"show run"

Copy all of those lines (except public addresses and passwords) and put them in here. If this gets too involved, I'd recommend you hire someone to save a lot of frustration. This could be a pretty simple setup though, but I'll need to see the config first.

HTH,
John

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[mondeospares]

Thanks John, ill post it as soon as the cables arrive.

Thanks again for all your help so far.

Ben.

[John Blakley]

It can do nat, but that's going to depend on how the router is configured if you'll configure it there or somewhere else. You mentioned that you had a network that wasn't moved over. Did you have other equipment like a firewall or another router by chance? Who configured this router that we're talking about now?

HTH,
John

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[mondeospares]

BT configured this router (cisco 1941) but this was before we moved over all the computers, printers, phone system etc so all that was at the new place was the new phone lines, dedicated internet line and cisco router, so I think they haven;t configured it properly (even though they say they have).

Before we had just standard broadband throgh a single phone line (like any residential person) and this was connected to a BT standard router (make/model: 2wire) and then this was connected to the switch.  Everything worked straight away without having to set anything up because the router did everything automatically like DHCP server, NAT etc.

(I wish we had just stuck to the standard broadband lol)

[John Blakley]

Hmmm...if they configured the router, you should contact them and have them configure nat/dhcp for you. If they manage the router for you, they should be able to get it to do what you need.

HTH,
John

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[mondeospares]

I'll contact them again on Monday, if I have no luck I'll post the config for the router.

Thanks again.

Ben.

[mondeospares]

Problem Fixed !!

Purchased a cable wireless router and this enabled DCHP sever, NAT etc.  Connected the Cisco router to the cable one I purchased to the network switch.  Why BT couldn't just tell me thhis from the start I don't know.

Thanks for all your assitance.