# Strange networking situation with strange terminology

## maiku

Recently I've gotten a T1 service.  The T1 company installed a router called the "Hatteras" and tell me to connect it to my system with a cross over cable.  They sent me an e-mail with IP information and blocks of static IPs (as they should) but they sent me two gateways and a range outside of the first gateway.  Here is the e-mail they sent. *Quote:*   

> The Hatteras has been installed and we're ready for you to test out your connection. You can use the following IP address when making a direct connection to the Hatteras with a single computer or as the WAN side of your router:
> 
> IP address: yyy.156.96.10
> 
> Gateway: yyy.156.96.9
> ...

 I plug the first IP address set into the interface and bam I get online.  But how in the world am I supposed to use the other IPs?  When I called them up they said that the 'Hatteras' device is just a bridge.

Usually my experience with T1s is that they just slap on a block of IPs and don't give me two different gateways even.  The T1 company is Speakeasy by the way.

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## ianw1974

Is one of the two gateways they sent you a router?  And the other is a bridge?

If so, you'll be looking at something like this:

LAN Ports --> Router --> WAN Port --> Bridge Device --> Internet

I only think this if I compare it to my DSL service, since I have an ethernet modem which bridges the wan port to the ethernet port on this modem.  I then connect this modem to the wan port on my firewall, and have an IP range I use internally for the LAN side of the firewall.  It is all I can think of in similar respects to mine on how it should look.  I don't have T1 here though, and never used it but the principal should be the same - I hope!

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## maiku

Actually there is no router provided.

Here is the setup.

Hatteras (bridge) -- (connected using crossover) --> Linux server --> Internal net

I'm assuming what I'm supposed to do, is set up the WAN Eth with the first IP (the one I list as yyy.).  Then set up certain machines internally with the xxx. addresses and have IP tables nat using a destination IP to the xxx IP address.  I'm not sure if I'm making any sense really.

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## Inodoro_Pereyra

They want a real pure IP router. You are not supposed to do NAT on that router.

Your ISP is telling you:

Hatteras (bridge)-- (connected using crossover) --> [WAN SIDE] Linux server [LAN SIDE] --> Internal net

The lan side of your linux server needs to have:

LAN IP: xxx.48.167.129

Your dhcp server needs to lease:

Useable Range: xxx.48.167.130 to xxx.48.167.158

Subnet Mask: 255.255.255.224 

Your DNS server (if is relaying), should do it to:

Primary DNS: xxx.254.95.2 

Secondary DNS: xxx.231.41.2

After that you can lease real IP address for internal hosts.

If anyway you want to do NAT, The WAN side of your linux server should have:

IP address: yyy.156.96.10 

Gateway: yyy.156.96.9 

Subnet Mask: 255.255.255.252 

Primary DNS: yyy.254.95.2 

Secondary DNS: yyy.231.41.2

And the LAN side of your linux server does not matter at all, just use whatever you where using until now and that should work.

Cheers!

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## maiku

So if I get this straight you are saying that I just need to set the WAN IP to the yyy series, then the LAN IP to the xxx series and set up the box as a router as I usually do?  I just don't have to set up any MASQ rules in iptables for the WAN iface, I guess.  Do I still have to enable net.ipv4.ip_forward?

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## ccp

ianw1974,

you said  *Quote:*   

> Here is the setup.
> 
> Hatteras (bridge) -- (connected using crossover) --> Linux server --> Internal net 

 

I am bit of confused, where the T1 line connect to?

What is the T1 line intended function? voice? or data?

Ping.

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## maiku

If you're talking to me the T1 connects to the Hatteras thing.

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## ccp

Maiku, I am sorry I guess check wrong frame. my question is direct to you.

Since you said it is connection to the Hatteras, I am guessing it is for data. so the other end of T1 is your other office or it is your ISP?

The reason I am asking is because base on the your early description it seems to me you already have internet connection through yous Linux server so I am not sure what is the T1 line is for.

My interpretation from the first post; I think this is what your vendor said,

```

Workstation 1

      xxx.48.167.130(default gateway xxx.48.167.129)

                    \                                                                                                           

Workstation 2  -------------------------> R o u t e r -------------------->  Hatteras (bridge) --(T1)-> ISP

                    /        xxx.48.167.129      yyy.156.96.10       yyy.156.96.9

Workstation n

      xxx.48.167.158(default gateway xxx.48.167.129)

```

Sorry, I can not make picture better  :Sad: 

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## maiku

The server was set up on the yyy. IPs that you see above and that worked for the server.  My question is, what do I do with the other IPs in the xxx series?

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## ccp

This is a little bit confusing, you said

 *Quote:*   

> The server was set up on the yyy

 

There were only two IPs given, one is yyy.156.96.10 and the other is yyy.156.96.9. The yyy...10 is the port address of your internal router. the yyy...9 is default gateway for the port. for example your internal router, port 1 is connect to linux server, say your port 3 is connect to Hatteras, then your port 3 address/network should be yyy.156.96.10/255.255.255.252 if you can set default gateway for the port? then it is yyy.156.96.9. So did you setup your linux server to be yyy.156.96.?? 

I amd affraid I really don't have good idea what do you want to do. Do you mind to explaing what is the your intented setup?

Ping.

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