Networking help - DPChallenge Forums

Tamron SP AF 17-50mm f/2.8 Di II LD Aspherical (IF) for Canon

05/18/2009 09:54:51 PM · #1

Not sure if this is the right place for this but I'm sure there are some networking gurus here.

My work is setting me up an office here so I can be based from home. The cable company came today and set me up a dedicated line and it got me thinking.....

Is there any way I can set something up between the modem and my wireless router so I can use my personal laptop on this same connection? My boss says it's cool if I can do it without putting the work computer behind a router (updates and all). Any ideas how to make this happen without affecting the work computer's IP?

05/18/2009 10:09:13 PM · #2

Your work computer should not be directly on the internet as it is. (If it is, then that is a very risky situation) It should already be behind a router. Most cable modems these days also combine the functions of a router and a 4 port switch. Assuming this is the case for you, then you should just be able to plug your laptop into a spare port and it should work, as long as the laptop is set to take an address from a router (called DHCP). The router presents the address that the ISP and internet see, and passes the data to the computer on your local network that needs it.

Since you already have a wireless router, that will likely then give you two routers. May require some more specific info on what you have and how it is configured.

Message edited by author 2009-05-18 22:10:40.

Tamron SP AF 17-50mm f/2.8 Di II LD Aspherical (IF) for Canon

05/18/2009 10:22:33 PM · #3

Solely a cable modem right now. They haven't brought the computer yet so I'm not sure if it will be behind a router. If they do I would be pretty certain they'll set up DHCP to not hand out more than one IP addy. The cable modem is just that; no spare ports.

What I'm trying to do is not affect the work computer but also be able to terminate my home ISP.

05/18/2009 10:32:10 PM · #4

It shouldn't affect it. You need to determine if the cable modem has a router and switch in it. If you can get the make and model number, that will help. Especially if they leave you with the user manual, then you will know exactly what you have.

I have a cable modem that is only a modem. It goes to a Netgear wired/wireless router/switch. The computers talk to the router and the router talks to the modem. I have 6 computers accessing the internet through this setup.

Message edited by author 2009-05-18 22:32:48.

Tamron SP AF 17-50mm f/2.8 Di II LD Aspherical (IF) for Canon

05/18/2009 10:54:07 PM · #5

It's an ambit u10c018. Pretty sure it's a simply a modem.

Nikon AF-S NIKKOR 24-70mm f/2.8G ED

05/18/2009 11:39:58 PM · #6

Is this it?

Yes, this is just a modem. No router, no switch. It will connect to 1 computer or other host (such as your router). You can run the ethernet port of this modem to the uplink port of your existing router/switch. Your router probably has some hard wired ports as well. Connect your computers through the router. The router will direct the traffic where it needs to go, and both computers can share the internet connection.

Message edited by author 2009-05-18 23:40:59.

pixelpig

Sony Alpha a55

Sony DT 1.8/50mm SAM

05/19/2009 12:03:50 AM · #7

Originally posted by Phil:

They paid for a separate line & brought you a plain cable modem because they don't want your work computer sharing a connection with anything. I think your boss said OK if you can do it without putting the work computer behind a router, was a way of saying No. On the other hand, nothing is imipossible. On the other, other hand if it was me I would not want my home computer sharing the same connection as my work computer, for security reasons. Security for me, that is. The bill is gonna be a big enough inconvenience. Good luck!

Citadel

Nikon D7500

05/19/2009 12:32:54 AM · #8

You could put a hub after the modem and then connect a router to the hub for your personal computer. That way your home PC would be behind the router and be protect and still have your work computer connected without a router in front of it. You could forego the router altogether but since you have one already you may as well use it.

Tamron SP AF 17-50mm f/2.8 Di II LD Aspherical (IF) for Canon

05/19/2009 10:48:00 AM · #9

Originally posted by pixelpig:

Originally posted by Phil:
Not sure if this is the right place for this but I'm sure there are some networking gurus here.

My work is setting me up an office here so I can be based from home. The cable company came today and set me up a dedicated line and it got me thinking.....

Is there any way I can set something up between the modem and my wireless router so I can use my personal laptop on this same connection? My boss says it's cool if I can do it without putting the work computer behind a router (updates and all). Any ideas how to make this happen without affecting the work computer's IP?

They paid for a separate line & brought you a plain cable modem because they don't want your work computer sharing a connection with anything. I think your boss said OK if you can do it without putting the work computer behind a router, was a way of saying No. On the other hand, nothing is imipossible. On the other, other hand if it was me I would not want my home computer sharing the same connection as my work computer, for security reasons. Security for me, that is. The bill is gonna be a big enough inconvenience. Good luck!

Nope. My boss is afraid that my router's firewall would hinder updates to my work computer.

The bill is being paid by my employer.

Tamron SP AF 17-50mm f/2.8 Di II LD Aspherical (IF) for Canon

05/19/2009 10:49:01 AM · #10

Originally posted by Citadel:

How will the hub hand out seperate IP addresses to the work computer and the router?

Canon EF 28-135mm F/3.5-5.6 IS USM

05/19/2009 11:19:18 AM · #11

Originally posted by Phil:

How will the hub hand out seperate IP addresses to the work computer and the router?

I don't think it will work the way he suggests unless you can have two IP addresses from the ISP. A switch does not give out IP adresses. All a switch does is route a communication to where it is meant to go. It does not control IP addressing, a router does that. (It is called NAT, Network Address Translation.

The router takes the single IP address that the modem is offering. The router then gives different IP addresses to all the devices that are on the internal network.

A router maintains connections to two networks: one on the inside, with your own computers attached to it and the router acting as server in some regards. The other connection faces the outside world and the router passes data back and forth. between the inside client and outside.

It is possible that a router could block some updates coming from the company, as a router is by it's very nature also a firewall. Only your IT department will really know how things are configured. However, I need to reiterate, if the computer is that exposed to the internet, it will more than likely be infected with a multitude of malware within minutes. Even if it is only on the ISP's network and not the internet at large, that still exposes you to everything floating around the ISP's network, including other customers PC's that may already have malware on them and are busy looking for open devices elsewhere.

The first and most important security device you should have is a router. Either they are configuring it that way already and you don't know it, or they don't know what they are doing. A router is a must, though many ISP's do not provide it or bother suggesting it. They consider it outside the scope of their responsibility. (I know a guy who works for Comcast tech support. I may ask him what their policy is.)

Maybe this quick and dirty diagram can help. This is also how my own home network is configured, though I have more computers on it.

Message edited by author 2009-05-19 11:44:35.

csolomon1

Canon EOS-50D

05/19/2009 11:46:23 AM · #12

The other option is to use a share connection, but this would require a seperate LAN connection so you would have 2 on the work computer, set one up to share internet connection to the router then the router would give your home PC a internet connection, but thats kinda complicated, you can research more online by looking up sharing an internet connection

Nikon AF-S NIKKOR 24-70mm f/2.8G ED

05/19/2009 11:53:36 AM · #13

Originally posted by csolomon1:

The other option is to use a share connection

That would work as well, but in that case your company laptop would be acting as the router for the other computers. Not quite as elegant a solution, as the laptop has to then be turned on and online for the other computer to get internet access.

Citadel

Nikon D7500

05/19/2009 11:58:30 AM · #14

Originally posted by Phil:

Originally posted by Citadel:
You could put a hub after the modem and then connect a router to the hub for your personal computer. That way your home PC would be behind the router and be protect and still have your work computer connected without a router in front of it. You could forego the router altogether but since you have one already you may as well use it.

How will the hub hand out seperate IP addresses to the work computer and the router?

As Yo_Spiff mentions...your ISP would need to give out at least two IPs. My ISP gives out up to 8. (Or it used to of course that may have changed. I use a router so I only use the one from them). Also as Yo_Spiff mentions, a router is the way to go. If your only concern is with updates? The router should allow those connections or it can be configured to allow them.

monaro_gto

Nikon D300

Nikon AF-S DX Zoom-Nikkor 18-55mm f/3.5-5.6G VR

05/19/2009 01:03:02 PM · #15

As others have said, this all depends on your ISP connection and your works connection method. Most basic internet modems (like comcast) assign one dynamic public address. If this is your work PC then you cant do much.

If you work is paying a little more a business class connection then you may have an external IP range of say 8 address'. If this is the case then you have options.

The other question would be how the work PC connects to your corporate network. I would say they will be providing either a basic wired or wireless router so that the PC is somewhat protected then you might use a VPN client or SSL VPN client to connect or they may provide you with another type of router that will connect for you.

Problem with this scenario is there are too many options until there is more information.

Basically you might be able to do it depending on how your work sets your office up.

relent

Nikon D80

Nikon AF Zoom-Nikkor 18-135mm f/3.5- 5.6G ED DX

05/19/2009 02:13:08 PM · #16

3 ways that I can think of.... (option 3 hasn't been mentioned yet)

1) ICS - link your laptop to the work computer and let it deal with the routing - not strictly puting it behind a router
2) request a /29 subnet off of your cable provide and buy a router that can handle this. This will enable you to put your work computer on a seperate IP and not firewall it. It still technically puts your work laptop behind a router, but then the internet is made up of routers and it works fine!
3) put the work pc behind a router and place it in the DMZ... problem with this is that it will involve network address translation and gives your work computer an internal IP. This is unlikely to cause a problem, but could be noticable

Regardless of how you do it, if you do it, it is foolish to place a PC directly onto the net as it sounds like your work PC currently is.

A hub has been menioned...this will not work, even if your cable company provide you with aditional IP's. To make this work you would need a router as mentioned in (2)

Message edited by author 2009-05-19 14:13:47.

Tamron SP AF 17-50mm f/2.8 Di II LD Aspherical (IF) for Canon

05/19/2009 06:14:05 PM · #17

Originally posted by Yo_Spiff:

Originally posted by Phil:
How will the hub hand out seperate IP addresses to the work computer and the router?

I don't think it will work the way he suggests unless you can have two IP addresses from the ISP. A switch does not give out IP adresses. All a switch does is route a communication to where it is meant to go. It does not control IP addressing, a router does that. (It is called NAT, Network Address Translation.

The router takes the single IP address that the modem is offering. The router then gives different IP addresses to all the devices that are on the internal network.

A router maintains connections to two networks: one on the inside, with your own computers attached to it and the router acting as server in some regards. The other connection faces the outside world and the router passes data back and forth. between the inside client and outside.

It is possible that a router could block some updates coming from the company, as a router is by it's very nature also a firewall. Only your IT department will really know how things are configured. However, I need to reiterate, if the computer is that exposed to the internet, it will more than likely be infected with a multitude of malware within minutes. Even if it is only on the ISP's network and not the internet at large, that still exposes you to everything floating around the ISP's network, including other customers PC's that may already have malware on them and are busy looking for open devices elsewhere.

The first and most important security device you should have is a router. Either they are configuring it that way already and you don't know it, or they don't know what they are doing. A router is a must, though many ISP's do not provide it or bother suggesting it. They consider it outside the scope of their responsibility. (I know a guy who works for Comcast tech support. I may ask him what their policy is.)

Maybe this quick and dirty diagram can help. This is also how my own home network is configured, though I have more computers on it.

I appreciate your help. I guess I could've explained my knowledge (or lack thereof) better as I already have a home network behind a router with several computers so I'm familiar with what a router does. This is why I said the work computer cannot be behind my router. It is also why I asked how a hub can hand out IP addresses since it is only a hub and not a dhcp server.

I guess my only option right now is to see what they bring when they set the hardware up. As monaro said, then we'll know for sure what I can do.

pixelpig

Sony Alpha a55

Sony DT 1.8/50mm SAM

05/19/2009 07:21:43 PM · #18

The bill is being paid by my employer.

That's what I meant. Is it billed to your existing account number? If so...if it was me, I'd want to re-negotiate. I would be surprised if your ISP can split the billing & provide your employer w/a separate account number for your home address. It's worth asking about.

Message edited by author 2009-05-19 19:22:10.