Internet connection sharing

[bob urz]

I have a unusual setup i am trying to do internet connection sharing on
The computer is a IBM A50 with built in Ethernet and video P4 3G.

The internet connection is cable internet over a Motorola surfboard
modem using USB connection to the IBM computer. The Ethernet is non
functional on the surfboard so don't suggest that route.

The internet works fine via the USB to the IBM computer.
now, i want to share that connection to a laptop using internet
connection sharing and a WiFi router.

The WiFi router can connect to the unused Ethernet port on the IBM's
mother board. Now how do i set up the port on the computer and the
WiFI router so i can share the connection Via WiFi?

bob

 

[VanguardLH]

I have a unusual setup i am trying to do internet connection sharing on
The computer is a IBM A50 with built in Ethernet and video P4 3G.

The internet connection is cable internet over a Motorola surfboard
modem using USB connection to the IBM computer. The Ethernet is non
functional on the surfboard so don't suggest that route.

The internet works fine via the USB to the IBM computer.
now, i want to share that connection to a laptop using internet
connection sharing and a WiFi router.

The WiFi router can connect to the unused Ethernet port on the IBM's
mother board. Now how do i set up the port on the computer and the
WiFI router so i can share the connection Via WiFi?

If you're wanting to use ICS (I don't know why you think you have to)
then you need *2* NICs in the gateway host.

http://en.wikipedia.org/wiki/Internet_Connection_Sharing
"ICS requires at least two network connections."

You'll need one NIC for the downstream hosts from your gateway host
(i.e., for your intranet hosts to connect to the gateway host) and
another NIC for the upstream connection (i.e., from the gateway host to
whatever gets it to the Internet, like to your router).

Since all the Ethernet ports on your router are defective (per your
statement) then you cannot normally connect your intranet hosts to those
Ethernet ports on your router. The USB connection only gives you a
single connection to the router. That's probably why you looked at
using ICS to use the gateway host (the one using USB to the router) to
connect your downstream hosts (laptop) going through the gateway host.
One NIC for downstream from the gateway (LAN side), one NIC for upstream
to the Internet (WAN side).

"The WiFi router can connect to the unused Ethernet port on the IBM's
mother board."

You'll have to explain that unusual setup. How does a WiFi router
connect to a physical Ethernet port on a host? It doesn't. The WiFi
router may connect to a WiFi NIC in your gateway host. WiFi connects to
WiFi. Maybe you meant that you have WiFi in both your gateway and
laptop hosts. If you think you have 2 NICs inside your gateway host
(the USB NIC that you connect to the router and a WiFi NIC to get from
laptop to gateway host) then why haven't you run the ICS wizard to set
it up?

Control Panel -> Network Setup Wizard

In the "External Links" section of the above Wiki article are two
tutorials on how to setup ICS.

Of course, for your laptop to have access, you'll have to leave your
gateway host powered on all the time (or during whatever times you want
to have Internet access on the laptop going through your gateway host).
You'll also have to consider security on the gateway host, especially
since you're using WiFi instead of cable to prevent someone else from
utilizing the WiFi for the LAN-side of your gateway host.

You have a cable or DSL modem to which you use USB to connect your
desktop (the gateway host). You want to connect more hosts. So why
haven't you considered getting a router (cabled or WiFi or both)? See
http://en.wikipedia.org/wiki/Router_(computing). Using a router before
the broadband modem is typically how users get multiple hosts to have
concurrent Internet access. You can get a cabled router or a WiFi
router (which often includes cabled ports) so you can use it with both
your desktop and laptop - and neither one has to use ICS to let the
other get Internet access. A hardware switch is faster, impervious to
hacks or malware, and more reliable than consuming CPU cycles on a
gateway host running Windows (or Linux).

The Ethernet port on the broadband modem is NOT for you to connect one
of your intranet hosts while you are also using its USB port to connect
another of your hosts. If you use the USB port then you cannot use the
Ethernet port. If you use the Ethernet port then you cannot use the USB
port. It's one or the other. Your broadband modem is NOT a router
(with an internal switch to funnel through multiple hosts). The modem
is a translator between communication protocols, not a switch for
Ethernet (see http://en.wikipedia.org/wiki/Ethernet_switch) which is
also the frontend for a router. You connect your computer (singular) to
the Ethernet or USB port on the modem, not your computers (plural) to
both of them. From your hosts, the broadband modem is a single-point
device: just one downstream host, like a router or ONE of your hosts,
connects to it. This is due to the config of the broadband modem by
your ISP. You are leasing just one IP address (for the WAN-side of the
modem) from your ISP. You only get one IP address allocated (through
the modem) to whatever is connected to that modem. It is not a NAT
device to multiplex multiple hosts to one IP address. You are limited
to just ONE network device (host or router) attached to the modem
because you only get a single IP address from your ISP to assign to that
connected device. Are you leasing more than one IP address from your
ISP? That'll cost extra money and you'll have to find out if your ISP
can provision the broadband modem to handle two IP address allocations
and make both the Ethernet and USB ports enabled on the modem.

If you have a working Ethernet port (RJ45) in your desktop (the ICS
gateway host) then you probably should use that instead of USB between
it and the broadband modem. USB incurs a heavier load on the processor
than does Ethernet.

I'm going by how to use the Surfboard 4100 and 5100 models. You never
mentioned WHICH model you happen to have.

 

[bob urz]

If you're wanting to use ICS (I don't know why you think you have to)
then you need *2* NICs in the gateway host.

http://en.wikipedia.org/wiki/Internet_Connection_Sharing
"ICS requires at least two network connections."

You'll need one NIC for the downstream hosts from your gateway host
(i.e., for your intranet hosts to connect to the gateway host) and
another NIC for the upstream connection (i.e., from the gateway host to
whatever gets it to the Internet, like to your router).

Since all the Ethernet ports on your router are defective (per your
statement) then you cannot normally connect your intranet hosts to those
Ethernet ports on your router. The USB connection only gives you a
single connection to the router. That's probably why you looked at
using ICS to use the gateway host (the one using USB to the router) to
connect your downstream hosts (laptop) going through the gateway host.
One NIC for downstream from the gateway (LAN side), one NIC for upstream
to the Internet (WAN side).

"The WiFi router can connect to the unused Ethernet port on the IBM's
mother board."

You'll have to explain that unusual setup. How does a WiFi router
connect to a physical Ethernet port on a host? It doesn't. The WiFi
router may connect to a WiFi NIC in your gateway host. WiFi connects to
WiFi. Maybe you meant that you have WiFi in both your gateway and
laptop hosts. If you think you have 2 NICs inside your gateway host
(the USB NIC that you connect to the router and a WiFi NIC to get from
laptop to gateway host) then why haven't you run the ICS wizard to set
it up?

Control Panel -> Network Setup Wizard

In the "External Links" section of the above Wiki article are two
tutorials on how to setup ICS.

Of course, for your laptop to have access, you'll have to leave your
gateway host powered on all the time (or during whatever times you want
to have Internet access on the laptop going through your gateway host).
You'll also have to consider security on the gateway host, especially
since you're using WiFi instead of cable to prevent someone else from
utilizing the WiFi for the LAN-side of your gateway host.

You have a cable or DSL modem to which you use USB to connect your
desktop (the gateway host). You want to connect more hosts. So why
haven't you considered getting a router (cabled or WiFi or both)? See
http://en.wikipedia.org/wiki/Router_(computing). Using a router before
the broadband modem is typically how users get multiple hosts to have
concurrent Internet access. You can get a cabled router or a WiFi
router (which often includes cabled ports) so you can use it with both
your desktop and laptop - and neither one has to use ICS to let the
other get Internet access. A hardware switch is faster, impervious to
hacks or malware, and more reliable than consuming CPU cycles on a
gateway host running Windows (or Linux).

The Ethernet port on the broadband modem is NOT for you to connect one
of your intranet hosts while you are also using its USB port to connect
another of your hosts. If you use the USB port then you cannot use the
Ethernet port. If you use the Ethernet port then you cannot use the USB
port. It's one or the other. Your broadband modem is NOT a router
(with an internal switch to funnel through multiple hosts). The modem
is a translator between communication protocols, not a switch for
Ethernet (see http://en.wikipedia.org/wiki/Ethernet_switch) which is
also the front end for a router. You connect your computer (singular) to
the Ethernet or USB port on the modem, not your computers (plural) to
both of them. From your hosts, the broadband modem is a single-point
device: just one downstream host, like a router or ONE of your hosts,
connects to it. This is due to the config of the broadband modem by
your ISP. You are leasing just one IP address (for the WAN-side of the
modem) from your ISP. You only get one IP address allocated (through
the modem) to whatever is connected to that modem. It is not a NAT
device to multiplex multiple hosts to one IP address. You are limited
to just ONE network device (host or router) attached to the modem
because you only get a single IP address from your ISP to assign to that
connected device. Are you leasing more than one IP address from your
ISP? That'll cost extra money and you'll have to find out if your ISP
can provision the broadband modem to handle two IP address allocations
and make both the Ethernet and USB ports enabled on the modem.

If you have a working Ethernet port (RJ45) in your desktop (the ICS
gateway host) then you probably should use that instead of USB between
it and the broadband modem. USB incurs a heavier load on the processor
than does Ethernet.

I'm going by how to use the Surfboard 4100 and 5100 models. You never
mentioned WHICH model you happen to have.

The modem is a SB5101. I think you miss understood me. The Ethernet port
OUT OF THE CABLE MODEM is not working. The USB port out of the
modem is working and functional with internet to the IBM computer
SO, i cannot do the typical put the WiFi 4 port router between the
computer and modem. The ports on the WiFi router are fine. The computer
is working using the USB connection from the surfboard. Eventually, i
might replace the surfboard, but its functional for now so that's what i
am rolling with

Now as i understand it, if i set up ICS, it assigns a fixed IP of
192.168.0.1 to the computers only Ethernet port? I have other PCI
cards to add more ports, but i did not think i needed to do this.

then Ethernet cable to any of the Ethernet ports on the router?
(not the WAN port, right?) any special settings on the router?
DHCP? Obviously i will set up the WiFI for username and encryption.

Thanks for all your help

bob

 

[Patok]

The modem is a SB5101. I think you miss understood me.

Of course he did. While quite knowledgeable otherwise, he needs 2 to 3 tries
to get what's being talked about; then his advice is spot on.

The Ethernet port
OUT OF THE CABLE MODEM is not working. The USB port out of the
modem is working and functional with internet to the IBM computer
SO, i cannot do the typical put the WiFi 4 port router between the
computer and modem. The ports on the WiFi router are fine. The computer
is working using the USB connection from the surfboard. Eventually, i
might replace the surfboard, but its functional for now so that's what i
am rolling with

Now as i understand it, if i set up ICS, it assigns a fixed IP of
192.168.0.1 to the computers only Ethernet port? I have other PCI
cards to add more ports, but i did not think i needed to do this.

then Ethernet cable to any of the Ethernet ports on the router?
(not the WAN port, right?) any special settings on the router?
DHCP? Obviously i will set up the WiFI for username and encryption.

It should work the way you describe it, you got it. The only thing to
remember is to set the router to not assign IP addresses (turn off its DHCP
server), and to assign it some fixed IP address so you know how to access it
and configure it from the network computers.

 

[Bob Willard]

I have a unusual setup i am trying to do internet connection sharing on
The computer is a IBM A50 with built in Ethernet and video P4 3G.

The internet connection is cable internet over a Motorola surfboard
modem using USB connection to the IBM computer. The Ethernet is non
functional on the surfboard so don't suggest that route.

The internet works fine via the USB to the IBM computer.
now, i want to share that connection to a laptop using internet
connection sharing and a WiFi router.

The WiFi router can connect to the unused Ethernet port on the IBM's
mother board. Now how do i set up the port on the computer and the
WiFI router so i can share the connection Via WiFi?

bob

You can do it right with a new modem and a new WiFi router.
Newegg: a new Moto Surfboard for $90 and a new Linksys WRT54G for $80
Or, new/refurb stuff from Ebay for less than half of the above.

I strongly suggest getting a real router with some wireless security
built in to protect your wireless net segment from unauthorized use. If
somebody uses your unprotected wireless segment to do nasty stuff (like,
say, uploading kiddy porn) you could become a criminal.

There may be a WiFi router which uses USB on the cableside, to save the
cost of replacing the Surfboard. I don't know of one, but I've never
looked.

 

[bob urz]

You can do it right with a new modem and a new WiFi router.
Newegg: a new Moto Surfboard for $90 and a new Linksys WRT54G for $80
Or, new/refurb stuff from Ebay for less than half of the above.

I strongly suggest getting a real router with some wireless security
built in to protect your wireless net segment from unauthorized use. If
somebody uses your unprotected wireless segment to do nasty stuff (like,
say, uploading kiddy porn) you could become a criminal.

There may be a WiFi router which uses USB on the cableside, to save the
cost of replacing the Surfboard. I don't know of one, but I've never
looked.

Here is the situation: finances dictate using the gear i got now
The surfboard works fine on the USB out to my IBM desktop.
i don't need to replace the surfboard now to get internet.
The Ethernet output on the surfboard is not operational

the surfboard hooks fine to the computer using USB. I can connect
the router (i have a couple of linksys) to the Ethernet port of the
IBM using internet sharing. granted this is NOT ideal, but it allows me
to occasionally use my laptop in my bedroom using a WiFi link.

So, the signal flow is cable modem USB/to/ computer/USB, computer
Ethernet out/ router Ethernet in.

set up ICS on the IBM desktop. This should set the Ethernet port fixed
IP to 192.168.0.1. make sure ESET firewall has an exception for the port.

Run Ethernet cable to one of the four Ethernet ports and NOT the WAN
port? Then set router to DHCP, and set up user name and encryption for
WiFi.

does this all sound correct?
In know i am going a pay a penalty in performance doing it this way,
but some internet is better than NO internet

thanks for all the help all

bob

 

[Patok]

Here is the situation: finances dictate using the gear i got now
The surfboard works fine on the USB out to my IBM desktop.
i don't need to replace the surfboard now to get internet.
The Ethernet output on the surfboard is not operational

the surfboard hooks fine to the computer using USB. I can connect
the router (i have a couple of linksys) to the Ethernet port of the
IBM using internet sharing. granted this is NOT ideal, but it allows me
to occasionally use my laptop in my bedroom using a WiFi link.

So, the signal flow is cable modem USB/to/ computer/USB, computer
Ethernet out/ router Ethernet in.

set up ICS on the IBM desktop. This should set the Ethernet port fixed
IP to 192.168.0.1. make sure ESET firewall has an exception for the port.

Run Ethernet cable to one of the four Ethernet ports and NOT the WAN
port? Then set router to DHCP, and set up user name and encryption for
WiFi.

Didn't you see my previous post? Yes, it is correct, except you need to
*disable* the DHCP server on the router, since the ICS will be giving out
addresses from then on.

 

[Paul]

Here is the situation: finances dictate using the gear i got now

Why not just wire the laptop to the desktop ?

If the laptop user is sitting at a desk, then a cable isn't going to
be that big a deal. Ethernet cables aren't free of course - when
I needed one the last time, I paid $10 for it.

ICS
Surfboard ------ USB ------- Desktop ------ Ethernet ------- Laptop

Also, I saw some used Surfboards on Amazon for $22.50, so getting
another old one doesn't have to be a full price experience.

Paul

 

[VanguardLH]

The modem is a SB5101. I think you miss understood me. The Ethernet port
OUT OF THE CABLE MODEM is not working. The USB port out of the
modem is working and functional with internet to the IBM computer
SO, i cannot do the typical put the WiFi 4 port router between the
computer and modem. The ports on the WiFi router are fine. The computer
is working using the USB connection from the surfboard. Eventually, i
might replace the surfboard, but its functional for now so that's what i
am rolling with

Now as i understand it, if i set up ICS, it assigns a fixed IP of
192.168.0.1 to the computers only Ethernet port? I have other PCI
cards to add more ports, but i did not think i needed to do this.

then Ethernet cable to any of the Ethernet ports on the router?
(not the WAN port, right?) any special settings on the router?
DHCP? Obviously i will set up the WiFI for username and encryption.

Thanks for all your help

bob

There is no "Ethernet port OUT OF THE CABLE MODEM" (where "out" means an
upstream connection). The only "out" (WAN-side) connection is to the
cable. *Both* the Ethernet and USB ports are "in" (LAN-side)
connections. You have 2 "data" downstream ports: Ethernet (RJ45) or
USB. You have one coaxial "cable" upstream port (RG6).

http://www.motorola.com/Video-Solut...-Gateways-and-eMTAs/Cable-Modems/SB5101_US-EN
- Optional USB 1.1 USB *data* port.
- 10/100 Base-T Ethernet *data* port.

See the manual, page 7, available online at:

http://www.motorola.com/staticfiles...ocuments/Static Files/SB5101 - User Guide.pdf

Yes, you CAN use a router with that router. It's the same one that I
have. Cable modem (Ethernet port) --> router (WAN-side Ethernet port)
--> router (LAN-side Ethernet or Wifi) --> computer (Ethernet or WiFi).

If "OUT OF THE CABLE MODEM" meant the Ethernet port (a data or
downstream or "in" port) is not working (to connect to a computer), is
that WITHOUT the USB port inuse? You get to use one or the other on the
cable modem because you only 1 IP address assigned to your use by your
ISP. If you unplug the USB cable from the USB port on the cable modem,
is the Ethernet port on the cable modem still inoperable?

If the Ethernet port on the cable modem is non-functional so you are
left with just the USB port on the cable modem, why not use a router
that has a WAN-side USB port (to connect it to the cable modem)?

Example:
http://www.tp-link.com/common/download/?resource=/resources/software/20111616204111.pdf
($25 at newegg.com)
page 4, Section 1.4.2, "The Rear Panel"
Shows a USB port. Says it connects to a cable modem. So this router
has a USB upstream port to connect to the cable modem's USB downstream
port. It has both wired and wireless connections to your hosts, so you
can hardwire your old desktop to it along with using WiFi from you
laptop.

Caveat: I don't know that the Motorola Surfboard 5101U is a 3GB cable
modem. The Surfboard isn't mentioned in their manual as tested for use
with this router but then manufacturers don't always list every
compatible device with their product.

Did you actually buy the cable modem or are you leasing it from your
ISP? I looked at the cost for buying one (and having to support it
myself) along with how often it had to get replaced (typically around 3
years) and I wasn't getting ahead of the cost curve versus leasing one
from my ISP. If leased from your ISP, call them and have it replaced.
If they have a local service center, you might be able to just walk in
and get an immediate replacement.

If you want no further cost to getting your laptop connected to the
Internet, and you don't want to swap the USB cable between the desktop
and laptop (which leaves one of them disconnected) then maybe ICS is how
you need to go. But how are you going to get the laptop wirelessly
connected to your desktop? Did the mashup string of "IBM A50 with built
in Ethernet and video P4 3G" mean you have wifi connectivity from the
desktop (if this was indeed a description of the desktop)? Does it also
mean that you have *two* NICS in your desktop (the one to get used as
the ICS gateway host): one Ethernet and one wifi?

It's a bit confusing because you mention wanting to use ICS on your
desktop (or whatever is that wannabe gateway host) and yet you also
mention a wifi router. Where you thinking of connecting your desktop
(ICS gateway host) via USB to the cable modem and then using the other
NIC (wifi or Ethernet) to connect to your laptop? Hmm, I'm not sure ICS
is going to see the USB connection as a NIC to include in its gateway
configuration. Does the USB device (USB port on desktop to USB port on
cable modem) currently show up as a connectoid listed in the Network
Connections applet in Control Panel? It might if an appropriate driver
to emulate a NIC were installed that would communicate over the USB
connection.

http://www.motorola.com/staticfiles...ocuments/Static Files/SB5101 - User Guide.pdf
page 7, Computer System Requirements, USB Connection
"The USB connection requires special USB driver software that is
supplied on the SURFboard Cable Modem CD-ROM."

So, if the driver is installed to emulate a NIC over that USB
connection, I'm guessing the USB connection is listed in the Network
Connections applet. If so, you should be able to use it in the ICS
setup.

http://www.conniq.com/WinXPNetworking_NetSetup2.htm

You'll want to setup the network bridge in ICS so the emulated NIC via
USB driver is on the WAN-side (Internet) and your Ethernet NIC is on the
LAN-side (intranet hosts) on your ICS gateway host. If you're using
your desktop as an ICS gateway host and if that host has wifi, I'm not
sure why you are still wanting to use the router downstream of the
gateway host since your other intranet hosts (laptop) have wifi.
Wouldn't you want to go wifi from laptop to desktop/gateway host? Why
go wifi from laptop to router and then wired from router to your
desktop/gateway host? Your ICS gateway host *is* the router and why you
need a decent firewall (and better than the simple one provided in XP).
ICS is the switch device, the router, the NAT host, and Internet
gateway.

Rather than get into all this (and I'm not an expert with ICS), it seems
replacing the cable modem with the defective Ethernet data port solves
all your problems right away. And if it's leased from your ISP then
there's no cost to you versus having to buy your own cable modem again
(and again and again in the future when those break, too). If it's your
cable modem (you paid for it and it's your property), maybe the RJ45
plug is bad. If so, open the case and replace the plug. It could be
the pins (wires) inside the RJ-45 plug are bent (often up so they don't
push down against the connectors pins) so just bend them back down. Not
enough info to know if the cable modem's Ethernet port is logically
defective (on a PCB inside the cable modem) or if just the RJ-45
connector is defective and can be repaired or replaced.

Even if you bought the cable modem, you might want to consider leasing a
new one from your ISP. I think the cost is typically around $3/month.
Somehow I don't see someone that is paying for Internet access from an
ISP not being able to afford $7/month. Computers and Internet always
cost money so they are restricted to those who can afford them. Yes,
you might be money poor but if you're that poor then maybe it's time to
give up on high-speed Internet and go back to an analog data/fax modem.
Paying for broadband Internet access after already paying for a computer
and then paying for later upgrades (software and hardware) but not being
able to afford leasing a cable modem (for awhile) is like saying you
want a Maseratti but cannot afford the water to wash it. Time to get
rid of the Maseratti, get a Saturn or Kia, and keep the cheapie
maintained. You might have to give up on high-speed Internet access if
you are so close to collapsing your finances that you cannot afford the
$7/month to lease a cable modem from your ISP.

You can go with the ICS scheme if you have the necessary network
hardware inside your desktop (gateway host) but it looks like you're
headed for a bunch of headaches versus just replacing the cable modem.
After all, you'll have to be paying for the extra electricity consumed
by your gateway host to have it powered and running ICS just to get your
laptop connected. If $7/month is going to bust your finances then give
yourself MORE breathing room by sacrificing the high-speed Internet
service and go slow until you can afford fast. Save up the savings when
you go to slow dial-up access to put against a new cable modem (if
you're still intent on buying your own) or until you accumulate enough
to afford the $7 rental unit and then go fast again. You'll spend less
than one-fifth (or less than one-tenth depending on limited versus
unlimited) on dial-up than for broadband. You can get dial-up access
for damn cheap and more than save enough in just 2 months in sacrificing
high-speed during that time than the cost of a new cable modem.

 

[N. Miller]

Run Ethernet cable to one of the four Ethernet ports and NOT the WAN
port? Then set router to DHCP, and set up user name and encryption for
WiFi.

Patok has it right. You are using the router as a switch, and the IBM
computer as a router. Disable DHCP on the router, and let the IBM ICS handle
DHCP.

Do keep in mind that the IBM is fully exposed to the Internet, and relying
on whatever firewall, if any is installed thereon.

As for the cost of replacing the hardware, surely you can forgo a case of
soda, or beer. Drink water and get a replacement for the modem!