Remote Connection To SLC 5/05 Via DSL Modem

Greetings,

I am trying to setup a connection to a SLC 5/05 via a DSL modem and am having problems. The setup is as follows: Sprint SP 645 Series DSL Modem; this connects to a Linksys WRT54G Wireless Router via CAT5 cable; from a switch port on the back of the router I am going to a Phoeinx Contact 5-Port switch via CAT5 cable, then to the SLC 5/05 Ethernet Port from the 5-Port switch via Ethernet. The IP Address of the SLC 5/05 is 192.168.3.102, Subnet is 255.255.255.0, and the Gateway is 192.168.3.1. (This is the internal IP Address of the modem. I thnk I read that the Gateway Address has to be set to the router's internal IP Address)

I can see the PLC on the LAN side of the network with no problem. I just can't see it from the internet. I have port 2222 forwarded on the router to the PLC IP Address. Can anyone help me with some suggestions as to what could possibly be the problem? Could the modem be blocking port 2222? Is that even possible? Any help or suggestions would be greatly appreciated.

Sincerely,

Kyle
PS: I know this is not a very secure way to connect to the PLC.

Bump... Still need help please...

This kind of question should be answered by your local supplier. I haven't done it with Ethernet, but connecting to A-B PLCs with serial has some delicate timing issues and generally requires an A-B modem. This may also be true of Ethernet.

I don't believe that its possible to do what you want with the linksys router. That product is designed to allow locally networked computers access the internet, not the other way around.

It may be possible to set it up to allow incomming connections to your PLC by disabling the router's firewall or configuring it properly, but I wouldn't bet on it. Even then, how does the router know where to forward the incomming packets intended for the PLC? (suppose for a minute that you had multiple PLCs on the local (192.168.xx.yy) network.

I presume that you can plug a computer into one of the WRT54G's ports and surf the net ? If not, then that is the first thing to take care of.

Put a switch/hub between the modem and WRT54G and plug a computer into it there. Can you see the PLC ? Good !!! You have port forwarding setup correct for the router.

Now, my best guess is that the DSL modem is also a router. If it has more than one LAN connection jack, then it is. Even if only one, then I still think so. You would need to set port forwarding in it too.

If your DSL modem has more than one ethernet port, you could plug the plc directly (via the switch).

With your computer connected, go to a command prompt and do a ipconfig /all to get what Gateway you have.

Or plug the switch into the DSL modem, then out of the switch to the plc and out of the switch to the WRT54G. This will make it simple and avoid haveing two routers in series. Which can be done (I have ) but is overly complicated in setting up everything just so.

Oh, also look at DHCP setup in both modem/WRT54G as normally it's on. You might want to limit it's range of addresses to what you are NOT setting staticly.

And, yes, I have done what you want, using a cable modem, with a VPN also thrown in the mix.

And after getting it all working, remember that your IP address may change. So look at DYNDNS.org for how other people can find yours via name.

theDave2: Thanks for the in-depth reply. I will take a look at all that you suggested and get back with you. I do know that the DSL modem is a router... Thanks again!