Cannot contact wired computer from wireless network

My Internet connection is as follows:

1) My cable modem connects to a hub.

2) My hub connects to two computers, by wire. My hub also connects to a Linksys WRT54G wireless router, by wire. All three devices have IP addresses 24.x.x.x and all three have the same subnet.

3) My WRT54G wireless router supplies Internet access to my laptop. My laptop gets (through DHCP) an internal IP 168.192.x.x.

Problem:

I cannot connect from my laptop to either of the wired computers in the network.

My WRT54G has built-in traceroute and ping functions. I cannot even use these features to ping my desktop computer using its IP address (24.x.x.x).

On my laptop, when I try to connect via ftp to my desktop computer, I see that the SYN_SENT packet has been sent when I run netstat. But my desktop computer does not receive the SYN_SENT packet.

When I am at school, connected to their wireless network, I can connect to my desktop computer without any problem.

Any one have a solution?

Reply to
Rory
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That's because they are separated by the router's NAT/firewall. Your desktops are on the public / WAN side with no protection at all, but your laptop is in the private / protected network.

Connect the modem to the wireless router, and connect the desktop PC to the LAN ports. You don't need the hub anymore. Now all machines will get the protection of firewall like NAT, a DHCP server, etc., they will be on the same 192.network, they will be able to see each other,etc.

In your existing config - the computers connected to the hub are at risk....as you can tell since you can easily get to them from the internet. Your desktops must be riddled with spyware, adware, Trojans, viruses, etc. You probably need some serious cleanup.

Under the new/correct config, if you want to access the machines that are behind the firewall - you will need to open the ports (ftp 23, http 80, etc) to get to them.

Reply to
riggor

Why does your modem connect to a hub and not the WAN port of the router?

Reply to
Tony

Other posters have addressed your post. Note IP of 169.xxx.xxx.xxx means network adapter is not getting a private IP (192.168.xxx.xxx) from DHCP but instead generates a 169.xxx address.

Reply to
JP

snipped-for-privacy@gmail.com (Rory) wrote in news:9a52281c.0501221653.1f78c694 @posting.google.com:

It should be connected to the router.

You don't need the hub anymore. The router has a built in switch that is better than the hub.

The laptop should be getting a private side IP of 192.168.xxx.xxx from the DHCP server on the router.

They need to be connected to the router.

If the hub was connected to the router, then you would be able to ping the machines on the LAN behind the router. You need the hub if you plan on extend your LAN because you have more machines that can be plugged into the 4 LAN ports on the router.

Why are you even doing it? Are you doing it to send and receive files. With the router as the gateway device, it will provide the ICS and you can set the machines to share resouces like it should be done behind the protection of a NAT router.

If those machines don't have a host based FW on them protecting them, they have most likely been hacked to death.

If you want to make contact with a machine behind the router over the Internet, then you must configure the router to open the appropriate port (s) by using the port forwarding feature of the router.

formatting link
You should keep the machines out of the DMZ.

The like also explains about NAT and the NAT router and also about hubs and switches. The router has a built in switch.

Duane :)

Reply to
Duane Arnold

I do not want to remove the hub, since I have multiple servers running on the wired computers (business accounts are allowed to do so). I'd prefer not to deal with port forewarding, so by using a hub, I do not need to deal with this.

I still do not think you have addressed the problem. From my laptop, which is behind the router, I should be able to communicate with my desktop computer (via ftp, http, etc.) just as if it were some computer miles away, since I'm using it's Internet IP address and not it's lan IP address. I am not setting this up like a lan.

Reply to
Rory

Hi Duane.

I have 5 IP addresses allocated to me by my internet provider, which is another reason that I have no problem with using the hub.

Reply to
Rory

Hi Duane.

I have 5 IP addresses allocated to me by my internet provider, which is another reason that I have no problem with using the hub.

Reply to
Rory

However, you also have each of your servers directly accessable from the Internet, and each of them necessarily must implement firewall functionality (all separately).

I see no reason that you cannot replace the hub with the switch, enable its firewall capabilities, and be *far* better off.

Whatever, if you want your laptop to have access to the two servers, all it takes is the proper routing table entries in the router. By default all you get is routing for the subnet that includes the router's IP address and a default gatewayed through the IP address you've entered as the access to the Internet. That is routing all traffic addressed to the two servers out to your ISP, and of course it never comes back...

Reply to
Floyd L. Davidson

Not nearly the same setup, just cable>WRT54GS>cat5>desktop/xp and WMP54GS in my garage PC/Win2K. After loading Win2k on new HDD I would get a network cable unplugged, coupled with a no internet access message. Followed all the Linksys help and troubleshooting tips and got nowhere. So, before I relinquished my dignity and called for help, I unplugged the modem and router from the wall. Gave it a few minutes, and fired it all back up. Connections made, everything's good. Honestly, I can't think of any other relevant thing that I did.

Reply to
nic

Hi Duane.

I wish I had purchased a switch instead of a hub, but at the time I didn't know the benefits that a switch offered over a hub.

When I move the laptop into the DMZ (I tried with both wireless and wired) I still cannot contact either PC.

(I've disabled all SW firewalls on the laptop and PCs and also the firewall capabilities of the router while testing.)

Reply to
Rory

Hi Dwain, thanks for all the help you've offered thus far.

Unfortunately, I bought the hub a few years ago before I really knew the difference between the hub and a switch. I wish I had bought a switch instead, but c'est la vie.

This is all correct.

solution for

When I put the laptop in the DMZ of the router (I tried both wireless then wired) I still cannot ping either of the desktop computers that are connected to the hub nor connect via http, ftp, etc.

I've turned off all SW firewalls on the laptop and two desktop computers while testing, as well as the firewall capabilities of the router.

I've sorta mentioned this earlier, but I'll say it again, just to confuse everyone even more. The router has built-in ping and traceroute diagnostic functions. From the router, I can ping my ISP's gateway, but I cannot ping my desktop computer, which shares the same gateway. It's so odd.

Reply to
Rory

Hi Floyd,

Yes, I wish it were a switch rather than a hub. But I'm not willing to purchase one, since neither of these machines are mission critical. Just development boxes.

Can you explain what you mean a little bit more? It sounds very interesting:

Whatever, if you want your laptop to have access to the two servers, all it takes is the proper routing table entries in the router. By default all you get is routing for the subnet that includes the router's IP address and a default gatewayed through the IP address you've entered as the access to the Internet. That is routing all traffic addressed to the two servers out to your ISP, and of course it never comes back...

Reply to
Rory

Hi Duane.

I wish I had purchased a switch instead of a hub, but at the time I didn't know the benefits that a switch offered over a hub.

When I move the laptop into the DMZ (I tried with both wireless and wired) I still cannot contact either PC.

(I've disabled all SW firewalls on the laptop and PCs and also the firewall capabilities of the router while testing.)

Reply to
Rory

"Rory" wrote in news:1106526729.559216.226200 @z14g2000cwz.googlegroups.com:

If you only have one IP from the ISP that covers your entire network, then I don't see how it's going to work. If you had more than one IP from the ISP and the desktop machine was assigned one and you had a modem that could handle more than one IP from the ISP, I could see it working somehow. I am no expert on this. I am curious as to where the desktop machine is getting its IP and Subnet from. You know where the laptop is getting it from which is the router.

Duane :)

Reply to
Duane Arnold

"Rory" wrote in news:1106540737.797837.202350 @z14g2000cwz.googlegroups.com:

Well, you may want to get switch as it will prevent network traffic collision and speed up the network.

So, you're saying that the laptop has normal Internet access and you can ping other internet IP(s) or www(s) from behind the router, but you cannot FTP, Telnet or anything not even ping the IP of the desktop machine that has a public IP assigned by the ISP.

What happens if you put the machine into the DMZ of the router and try something of course protecting the machine with a personal FW solution for the test? And what happens if you do it with a wire connection from the DMZ of the router or from behind the router with a wire connection can you establish a connection? I'll assume that the desktop machine has a FW protecting it that you must set rules to open the appropriate ports.

Duane :)

Reply to
Duane Arnold

Is your ISP using a DHCP network? So the IP address for both your wired

PC's are coming through the modem, then through the hub, and to the

approprite PC...

Then you have a wireless router on the same LAN with DHCP enabled

using the same hub as the modem and the wired PCs...

Also what OS are you running on the desktops and laptop?

Rory Wrote:

Reply to
netcat

He's already got one!

And how to utilize the equipment he already owns...

Reply to
Floyd L. Davidson

The original message said he has a modem feeding a hub, and the hub has 2 servers and a Linksys WRT54G wireless router/switch providing access to a laptop.

All he really needs to do is swap the hub and the WRT54G, enable the firewall and routing facilities in the WRT54G, and he's got exactly what he wants to have.

Reply to
Floyd L. Davidson

With different IP addresses assigned by your ISP? This makes a difference to the topology.

Then plug the hub into one of the wired ports of the router.

So you are intentionally putting your desktops outside your firewall? Why? Why not set it up as a lan ?

Reply to
Mark McIntyre

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