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CASE SOLVED - I.C.S: With 2 PCs & no router/Switch

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  • Routers
  • Networking
Last response: in Networking
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July 27, 2006 6:47:33 AM

Hi all,

recently, i am helping to connect a 2nd PC so that it can also access the internet. Let me call this PC "Client PC"

Due to some constraint in this project, no router will be bought so i'm installing a 2nd network adapter/card into the existing PC with internet access and enable ICS. Let me call this PC - "Main PC"

I have followed a guide as stated here - http://www.practicallynetworked.com/sharing/xp_ics/ (Including setting the IP addresss as stated on the 4th instruction on this page - http://www.practicallynetworked.com/sharing/lansetup2.htm)

Now, Client PC's ethernet outlet is linked with the 2nd, newly installed network adapter outlet at the Main PC with a CROSSOVER cat5e cable.

Both PC is able to detect and link to each other, the network icon notifications at the taskbar showns no issues. Everything is working fine as both computers sports the same Workgroup name and i can share files with each other w/o problems. Pinging each other isn't a problem also.

But i just can't get the Client PC to access the internet...So what's missing?

Thank you in advance!!

More about : case solved pcs router switch

July 27, 2006 1:40:40 PM

On the client PC, are you using DHCP or have you manually set the IP address? Can you ping the IP address of the main PC's network card which is connected to the Internet (I.E. not the 192.168.x.x IP address)? If so, then ICS would seem to be working. If not, then you need to look at ICS on the main PC again because it is not forwarding packets from the private network.


Have you checked to see if it's perhaps a DNS issue? On the main PC, try pinging a website (I.E. google.com), then try to ping that IP address on the client PC. If you can ping the IP address but not the hostname then it might be a DNS problem.
July 27, 2006 2:08:36 PM

The dual home PC does not have packet forwarding turned on.

Quote:
Hi all,

recently, i am helping to connect a 2nd PC so that it can also access the internet. Let me call this PC "Client PC"

Due to some constraint in this project, no router will be bought so i'm installing a 2nd network adapter/card into the existing PC with internet access and enable ICS. Let me call this PC - "Main PC"

I have followed a guide as stated here - http://www.practicallynetworked.com/sharing/xp_ics/ (Including setting the IP addresss as stated on the 4th instruction on this page - http://www.practicallynetworked.com/sharing/lansetup2.htm)

Now, Client PC's ethernet outlet is linked with the 2nd, newly installed network adapter outlet at the Main PC with a CROSSOVER cat5e cable.

Both PC is able to detect and link to each other, the network icon notifications at the taskbar showns no issues. Everything is working fine as both computers sports the same Workgroup name and i can share files with each other w/o problems. Pinging each other isn't a problem also.

But i just can't get the Client PC to access the internet...So what's missing?

Thank you in advance!!
July 27, 2006 2:11:03 PM

Quote:
The dual home PC does not have packet forwarding turned on.


That's a pretty big assumption to make without doing any troubleshooting first. It could be any number of problems.
July 27, 2006 2:16:47 PM

@Fred, thanks for taking the time to reply me

As stated in my first post, i used the step 4 in the guide in this link - http://www.practicallynetworked.com/sharing/lansetup2.h... to set the IP address.

My Main PC's 2nd network adapter is given an IP address of 192.168.0.1
My Client PC's network adapter is given an IP address of 192.168.0.2

I can ping my main pc's network card without problem, but what do ya meant by, "not the 192.168.x.x IP address", then how do ya ping it then?

@el0him, thanks for replying.

Your "dual home PC", do ya meant the Main PC in this case? Hmm...interesting, both of you mentioned packet forwarding...Where do i enable it or check if it is enabled?

Thank you!
July 27, 2006 2:35:59 PM

By default, windows does not turn on packet forwarding. If you want to forward the packets between the two networks, you have to turn it on. It doesn't matter if you turn on ICS. That just gives it NATting functionality. You also need routing functionality if you want to forward packets to other networks.

Registry Settings
System Key: [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters]
Value Name: IPEnableRouter
Data Type: REG_DWORD (DWORD Value)
Value Data: (0 = disabled, 1 = enabled)
July 27, 2006 2:42:17 PM

Quote:
By default, windows does not turn on packet forwarding. If you want to forward the packets between the two networks, you have to turn it on. It doesn't matter if you turn on ICS. That just gives it NATting functionality. You also need routing functionality if you want to forward packets to other networks.


That's deceptively true. NAT is a form of packet forwarding, and that's what I was referring to. The packet forwarding you're thinking of doesn't need to be enabled for ICS to function correctly. But like you said, if you wanted to route between networks instead of NAT from one to the other, then yes, you'd need to have packet forwarding turned on and NAT turned off. Can XP even do that? I know in Server you have to enable RRAS.

But that's beside the point. xanvier, you have two network cards. One is connected to your ISP and the other is connected to your 2nd computer. From the second computer, you want to ping the network card that is connected to the ISP. Hence, it will have a public IP address, not a private address like 192.168.x.x. Just go to your main PC on a DOS prompt and type IPConfig. You will see both your network cards, the 192.168.x.x one and the other one which will have a different IP address from your ISP. Take THAT address and try to ping it from your 2nd PC. This will do a very basic test to see if your main PC is forwarding packets from the internet NIC to the external NIC.
July 27, 2006 2:58:08 PM

Thank you fred, i perfectly undertand what you meant now. :) 

I'm not able to do it now. I will go and ping the public IP address given by the ISP on the client PC(2nd PC) later.

However, i have a feeling this test is going to fail, after all i already can't access the internet on the 2nd PC...LOL~ Darn. If that is the case, what should i do then? Ok, ok...i let ya guys know later. :) 

P.S: I saw something like setting up "Network Bridge" & "Internet Gateway" mentioned in the guide i stated in my 1st post, is it gonna help me here in anywhere? If no, then it's ok, i don't want ya to waste ya time explaining to a beginner to me now.

@el0him: Thank you for the advice. ;) 
July 27, 2006 4:02:43 PM

If it doesn't work, then you have issues with ICS. I guess try reenabling it. I didn't read the guide you linked, but all you should really have to do is check the sharing box on the properties of the Internet interface.
July 27, 2006 4:49:53 PM

Lol~ Geez...I see... Oh well, i will try that too. Btw, on the main PC, the ICS option is displayed only on the network adapter that connects to the internet, not the 2nd adapter that links with the client PC.

Erm...that should be the correct behaviour in Windows XP right? :p 

Ok man, thanks for the help nevertheless everyone.
July 27, 2006 5:54:57 PM

That's right.
July 28, 2006 12:36:58 PM

Well...i tried and everything seems to work but not internet access.

At first i thought i hit the jackpot when i discovered that i did not enter in the default gateway address for the client PC's TCP/IP properties.

I then proceed to put in the IP address of the network adapter of the main PC, as stated on the step 4 of the guide - http://www.practicallynetworked.com/sharing/lansetup2.h...

But still it's not working. :( 
July 28, 2006 6:05:43 PM

Quote:
Have you checked to see if it's perhaps a DNS issue? On the main PC, try pinging a website (I.E. google.com), then try to ping that IP address on the client PC. If you can ping the IP address but not the hostname then it might be a DNS problem.
July 28, 2006 7:35:39 PM

You are trying to get your main pc to act as a router. It will never act as a router unless you enable packet fowarding. What does this mean? This means that the main PC will never send traffic from one interface to the other.
July 29, 2006 2:09:09 AM

Quote:
You are trying to get your main pc to act as a router. It will never act as a router unless you enable packet fowarding. What does this mean? This means that the main PC will never send traffic from one interface to the other.


No, he's trying to get his PC to do NAT, which is different than functioning as a router. Namely, there are no routing protocols with NAT and there is no address translation with routing. A router is bidirectional in the sense that it passes packets from either network A to network B OR network B to network A. NAT is unidirectional in the sense that it will only translate addresses from one network that are destined for the other; the public interface cannot route back to the NAT interface. Enabling ICS is all that should be necessary to do what he wants.
July 29, 2006 2:11:33 AM

Quote:
Well...i tried and everything seems to work but not internet access.

At first i thought i hit the jackpot when i discovered that i did not enter in the default gateway address for the client PC's TCP/IP properties.

I then proceed to put in the IP address of the network adapter of the main PC, as stated on the step 4 of the guide - http://www.practicallynetworked.com/sharing/lansetup2.h...

But still it's not working. :( 


By the way, I didn't see a post from you reporting whether or not you could ping the IP of the Internet LAN card on your main computer. If you just say "no Internet" or "it's not working" when we've given specific troubleshooting instructions it gets kinda frustrating. 8O
July 31, 2006 9:33:05 AM

Apologies! It was already weekend and i can't test stuff out when i don't have access to them since everything is locked in the office.

1.
Quote:
Have you checked to see if it's perhaps a DNS issue? On the main PC, try pinging a website (I.E. google.com), then try to ping that IP address on the client PC. If you can ping the IP address but not the hostname then it might be a DNS problem.


So may i know if the IP address to ping with the client PC in this case, is the one that i received when i pinged a website(i used www.yahoo.com and it returned "www.yahoo.akadns.net [209.131.36.158]) using the main PC?

2.
Quote:
...ping the IP of the Internet LAN card on your main computer.


Alright, with my main PC, i pinged my LAN card that is connected to the net. The IP address in this particular card is 192.168.1.2. Here's the result -

Quote:
Pinging 192.168.1.2 with 32 bytes of data:

Reply from 192.168.1.2: bytes=32 time<1ms TTL=128
Reply from 192.168.1.2: bytes=32 time<1ms TTL=128
Reply from 192.168.1.2: bytes=32 time<1ms TTL=128
Reply from 192.168.1.2: bytes=32 time<1ms TTL=128

Ping statistics for 192.168.1.2:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms


Thank you and have a nice day! Sorry for the inconveniences caused! :) 
July 31, 2006 1:22:30 PM

Perhaps you need to draw us a picture of how your network is hooked up. Your Internet interface should not have a private IP address such as 192.168.x.x.

From what you have said you have something like this:

[PC2]e0 => e0[PC1]e1 => Internet

PC2's e0 is connected to PC1's e0 with a crossover cable.

PC1's e1 is connected to the Internet via some sort of modem.

Your Internet interface is always the interface closest to the Internet, in this case e1 on PC1.

Just go to PC1 and run ipconfig, then paste it in to your reply.
August 1, 2006 4:29:16 AM

PC1(main PC), which has 2 network cards;

1 of which(e1) connects to the (Internet) with a ADSL(DLINK-500T) modem(external ADSL modem with built in router - http://www.dlink.com.sg/products/?pid=310);

the 2nd card(e0) connects to PC2's(client PC) network card(e0) using a crossover cable.

This is the "ipconfig /all" for PC1(Main PC) -

Quote:
Windows IP Configuration

Host Name . . . . . . . . . . . . : goodeal-zomzaex
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : Yes
WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Local Area Connection 2:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Winbond W89C940-Based Ethernet Adapt
er (Generic)
Physical Address. . . . . . . . . : 00-80-48-CA-BD-24
Dhcp Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 192.168.0.1
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . :

Ethernet adapter Local Area Connection 1:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Realtek RTL8139/810X Family PCI Fast
Ethernet NIC
Physical Address. . . . . . . . . : 00-0D-61-7D-B1-88
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 192.168.1.2
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.1
DHCP Server . . . . . . . . . . . : 192.168.1.1
DNS Servers . . . . . . . . . . . : 192.168.1.1
Lease Obtained. . . . . . . . . . : Tuesday, August 01, 2006 11:56:20 AM

Lease Expires . . . . . . . . . . : Tuesday, August 01, 2006 12:56:20 PM


Just as an extra, here's the "ipconfig /all" for PC2(client PC)(i was able to get it saved in a *.txt file and shared it using "file sharing" feature of winXP) -

Quote:
Windows IP Configuration

Host Name . . . . . . . . . . . . : GOODEAL-IBM
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Mixed
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) PRO/100 VE Network Connecti
on
Physical Address. . . . . . . . . : 00-0D-60-3D-CF-17
Dhcp Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 192.168.0.2
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.0.1


Thank you very much and good day to ya!
August 1, 2006 5:37:50 AM

Ok, your modem has a built in router. Let me just say that you could save yourself a bunch of headache now and down the road by spending $5 on eBay for a used 10mbps hub, so you could connect both PCs to the modem instead of using ICS.

So, from the client PC (the one with only 1 network card) ping the address of the Dlink router, 192.168.1.1. If you can ping that, then ICS is working. Just keep going 1 step further away, i.e. if you can ping the main computer, then try pinging the router, then try pinging your isp, then try pinging some random website, etc.

Also, are you sure you pasted the complete output from ipconfig /all on the client PC? You are missing DNS server info. So if you forgot to enter that in, use 192.168.1.1, since it seems to be working fine for your main PC.
August 2, 2006 5:08:38 AM

Ok solved!! It works it works!

I followed ya advice of adding the DNS server address of 192.168.1.1 on the client PC into the "Preferred DNS server" entry.

Once this was enterred, with all the previous settings followed in the previous replies i gave, internet access is now available on the client PC.

Case solved! :) 
August 2, 2006 6:17:36 AM

Hi Fred & el0him,

i just want to personally say thank you, abielt virtually, for helping me all these while. I appreciate that!
!