POS (point of sale) terminal

[johnyb98]

Hello everyone!

 

I want to connect a POS terminal to work via ethernet port. I want to make it work with static IP address.

For sure, I will give it the address and subnet mask.

I give the following information that is now.

Router IP:192.168.1.1 with subnet mask 255.255.255.0

There is only one pc in the network with 192.168.1.2 and subnet mask 255.255.255.0

Let's say, that in the POS terminal I give 192.168.1.3 with 255.255.0.0

My question is:

On POS terminal, what of the following should I also fill in:

Gateway ?

DNS1 ?

DNS2 ?

 

All three? None of them? Some of them? Which? And if yes to some/all of them, with what ip address?

 

Thank you for your time!

[mariushm]

I would give it 192.168.1.101 or something further away from the other computers. 

if you add or remove computers, if there's some power failure for example and computers which have DHCP enabled (auto get IP from router), they may turn on faster than the POS and "steal" that IP from the POS and then the POS will be stuck in a loop, unable to take the fixed IP address for itself. 

 

DNS is only needed if you want the POS to have internet access. If so, use the IP of your ISP's DNS or use a public dns like Google's (8.8.8.8 / 8.8.4.4)  or Cloudflare (1.1.1.1) or OpenDNS  (208.67.222.222 or 208.67.220.220) .. these are just 3 examples. 

 

Gateway ... leave empty (i'm not 100% sure) but you shouldn't need it.

 

Only IP and subnet mask are needed for network communication.

 

PS. Keep in mind that some routers which also have wireless, are configured by default to assign IPs to devices connected wireless  from a specific range, like for example starting from 192.168.1.201 onwards, or something like that. 

basically, just keep a "buffer" between your fixed ip devices and ips that are assigned automatically to devices.

 

[johnyb98]

WooooooW!!!! I am working with networks 15+ years, and the scenario you are talking about (the way the POS ip could be "stolen"), is something I have never thought of. Neither a colleague or teacher have ever said, too. I must accept you are a MASTER networking!!! Thank you!!

 

Now, for the matter of the thread. It's because I try to understand some things on POS terminals, but it's not only POS matters. Here, networking is taking full place (if we could give it such tag).

So, I have also two questions.

 

a. It's about the gateway. Without wanting to dispute you, I think this is something should be filled in. Here, the POS gateway address that should be filled in is the router's IP address. In our matter, 192.168.1.1 and I explain why.

From the moment the transaction takes place, the transaction should be carried from the local network to the out world. So, this is something that is router's job. But, how POS will communicate with router? This is where gateway comes into game. Having filled POS' gateway address with router's IP address, this communication can take place. So, gateway, for transactions, is something that must be filled in.

As for DNS1 and DNS2, I totally agree with you that can be left empty. They exist, and can be filled in, for other reasons. As far as it concerns ONLY POS transactions, they can be empty.

 

This is my a. question. I would like to read your thought about all that, and, if I solve my a. question, I can proceed to b.

 

Thank you!

 

 

[mariushm]

I'm not a master, just the fact that I'm not sure about the Gateway bit would point that out. Try with your router's IP address for gateway. You could also open a command prompt in Windows and type ipconfig and see what gateway Windows detected / uses.

 

You didn't hear a lot about that IP stealing because a lot of routers have timeout periods, keeping the IP locked to a MAC address for some period of time, like 1h or 24h or even more.  If the computer is shut down, or there's a brief power failure and router resets, it should "remember" that less than 1h/24h/n days have passed and continue to keep an IP reserved and not assign it through DHCP to other network devices.

 

But, some devices are buggy, or don't have such features or these features are not enabled, and it's a good habit to either double check, or to just leave some separation between IPs.

 

Also, a lot of routers will have their DHCP server configured to only give IPs within some range, like for example 192.168.1.64...200 , then wireless devices from .200 up to 254 , leaving the ones below .64 to be used for fixed IPs.

 

 

 

[johnyb98]

Yes, what you are saying above is IP lease time. It's something I also though of seeing your first answer. That the address could not be stolen if router's recovery time is inside lease time period.

 

Unfortunately, now talking, I am not in working place and I cannot see command prompt ipconfig output.

 

I would like to proceed to question b.

 

It's about POS ports. Two ports (if I have understood well) : 443 and it must be 6556.

In order to clear this out, I would like to give POS product:

INGENICO ICT220

 

But, it's not about specific product. I think that POS terminals have an internal logic port (like 6556). I will explain about 6556 second. First, let's clear out about port 443.

Turning on INGENICO ICT220 as I saw in a video, it asks to confirm some by default given from manufavturer settings via green button (Enter):

- One : is a public IP (it must be some server's IP)

- Two : is port 443

And then proceed to communication test with "Enter".

 

This network socket (WAN public IP + port) must be a POS system where transactions are carried. So, port 443, is the final server's port of the outside world. Have I understood it well?

If I have understood it well, I think that in our firewall settings, either router's firewall or O/S' firewall, outbound 443 port should be open. So, IF outgoing 443 port is blocked, POS transaction cannot be completed. In that case, we should create an outbound open 443 port rule. Are all these correct or am I missing or say something on all these? 443 port is what I mention?

[Master Disaster]

As for Gateway & DNS, generally you can set these to your routers IP if you want internet access.

 

The Gateway is the physical device that provides your internet connection, your router or modem.

 

DNS is Domain Name Server, the IP of the server that handles converting URLs to IP addresses.

 

Most (more than likely all) Routers will handle DNS forwarding so you can point to the router as your DNS and it will forward requests on to your ISP automatically.

[johnyb98]

You describe it very nice. But I have make it all a mess because we always see on static given PCs as DNS1 the router's address. Usually the same as gateway.

 

Also, it makes me make it a mess the fact that in one device comes all three :

modem

router

switch

 

I think they are all three different devices, we give gateway same as DNS, but I think, although most of the times gateway is same as DNS1, in true, it refers to different device!!!