Who gives out IP addresses?

[Corley]

Say you have a wifi ranger with a tethered hot spot and hard wired eithernet WAN connections. Which device is assigning the LAN IP addresses to devices when they connect via wifi or eithernet cable? The two WAN sources will potentially each have different IP ranges set, and the wifi ranger has it's own IP address.

Same question, but substitute a Pepwave for the wifi ranger?

Background for this question: I just signed up with T-Mobile for their home internet, and I plan to take this with me in the RV when I travel, but I also intend to use it at home for my internet service. At home, I have a wifi ranger, and I will connect the T-mobile box via cable to the wifi ranger. Since we are in a very poor cell reception area, I will also tether a cell phone to the wifi ranger for better throughput during congested time. When traveling, I have a Pepwave in the RV, and will basicially do the same thing. But, I would like to understand what IP range is going to be assigned in both cases.

Please forgive me if I got this wrong, I am an idiot.

[l1v3fr33ord1]

Corley-

The simplest is to let the routers (WiFi Ranger, Pepwave) assign IP addresses to the wired and wireless devices. As you use different routers at home and on the road, configure them to assign the same addresses. Just don't run both routers at the same time.

Me, I used the Pepwave in both places, moving it from house to coach and back, as needed. My devices didn't know the difference.

As a rule, you need not be concerned with the IP addresses used on the WAN connections.

You need to be a bit careful doing this, but you should disable IP address assignment on the WAN devices, such as the T-Mobile home device, or a cellular hotspot (this Verizon JetPack), if you had one. That way all user devices, such as a tablet or laptop or printer get their IP addresses from the router, and not the WAN devices. I say you need to be careful because the WAN devices need to communicate with the routers, and if you are not careful you can make it difficult/impossible to communicate. If that happens, reset the WAN device to defaults and start over. You do keep a copy of its successful "config" file to reload, didn't you?

[Corley]

Mark,
Thank you for the reply. There are a few issues with what you suggest, however, that I don't know how to overcome.

First, the T-Mobile Home Internet gateway does not allow one to get into the settings at this time. (This is only true with their latest black tower, as I understand it.) So it is impossible to modify any settings in this box, it is literally a "black box".

Next, while it MAY be possible to get a tethered Android phone to not assign IP addresses, that seems way beyond my capabilities, as it requires creating some sort of file with settings, which I know nothing about, and possibly requires rooting the phone, This is beyond my ability.

Lastly, while I don't have either the wifi ranger nor the Pepwave in front of me right now, I don't think it is possible to have them assign IP addresses. I might be wrong on that.?.

But, in the end, the question that I asked remains, in the scenario I proposed, which wan source provides and assigns IP addresses when new devices are connected? Since there are two WAN sources (or possibly more), it would seem that an IP address COULD be assigned from either or both, which would present a problem since that would mean devices on one of the lans might not be able to 'see' devices on the other lan. (Different IP ranges would mean, effectively, multiple lans.)

I appreciate your alternate solution suggestion, but given that it is not possible to implement, I'd still like to understand what determines which WAN source will assign the IP addresses.

Thanks for any answers to the original question.

[l1v3fr33ord1]

Corley-

To answer your question: None of the WAN sources should provide or assign LAN IP addresses. The router should.

If I knew the WiFi Ranger and Pepwave model names/numbers I could read the manuals and confirm what I expect, which is that both are able to assign IP addresses to your locally-connected wired and wireless devices.

An example is the Pepwave Surf SOHO, which I used in the two coaches I owned and now have at home. There is a section in the configuration where I define what IP address range I want on the LAN. Each device at my house or in my coach "requests" an IP address from the Pepwave router, and the router responds with an IP address in the range I defined. That's the simple explanation on how it works.

[There should be a similar configuration section for the WiFi Ranger. I owned one of those, too.]

On the WAN side, the router has additional IP addresses that it uses to communicate between the router and any WAN connection devices, such as hotspots, home Internet adapters, and the like. You can configure those IP addresses, too, but here's the important point:

None of the end-user devices- that is laptops, tablets, TVs, cell phones with LAN connections, printers, etc.- need to know what those WAN addresses are. The router and the WAN devices do, but not the end-user devices. The end-user devices only need to have valid LAN IP addresses.

That's the beauty of using a WiFi Ranger or Pepwave (or another manufacturer's) multi-WAN router. You don't need to change IP addresses on your devices as you change WAN connections. The router does all the magic for you.

[docj]

Originally Posted by Corley

Mark,

But, in the end, the question that I asked remains, in the scenario I proposed, which wan source provides and assigns IP addresses when new devices are connected? Since there are two WAN sources (or possibly more), it would seem that an IP address COULD be assigned from either or both, which would present a problem since that would mean devices on one of the lans might not be able to 'see' devices on the other lan. (Different IP ranges would mean, effectively, multiple lans.)

Your question is a good one. It's usually considered better not to have multiple devices performing the DHCP function (assigning addresses) because it can cause problems as you have described. It's better to put one of the devices into a "bypass" mode so that only one device is responsible for assigning addresses. If you read some of the threads about Starlink that's what's done when connecting the round dish into your local network. The Starlink router is put into bypass mode so that the WiFiRanger (or other router) provides the DHCP function.

However, as you've already noted it's not always possible to put your router into bypass mode. Fortunately, having two devices in a row performing the DHCP function isn't as bad as it sounds. You will see people referring to this as a "double NAT (network address translation)" but in most cases it really doesn't cause a problem. It can cause a small reduction in throughput speed but in most cases that's the only noticeable effect you will encounter.

I've tried to explain this in non-technical language; I apologize to those who will judge my response as being too simplistic.

[tetranz]

I think all the above is correct but it doesn't really answer what you should do.

As I understand what you're saying:

• The T-Mobile device is a black box that you can't change.
• Like most home internet routers, it has its own DHCP server.
• In the normal / simple situation as T-Mobile intends, you connect to it from your client devices (laptop, Roku etc) with Wi-Fi or ethernet and it gives them an IP address from its DHCP range.
• You don't want to use it directly but have a Pepwave as your main router and want to use the T-Mobile for the WAN.
• The Pepwave also has a DHCP server. That's the main one your client devices use.

That all makes good sense.

The solution is that you need to configure the Pepwave WAN port to act as a DHCP client. This is quite separate to the Pepwave's DHCP server.

I don't know what model Pepwave you have but look here https://download.peplink.com/manual/...manual-fw7.pdf and go to page 62 which talks about how to setup the ethernet WAN. DHCP is one of the options listed at the bottom of page 64. It looks like you just need to set it instead of one of the other three choices.

Do that and it should work. Your client devices will get their IP address from the DHCP server in the Pepwave. They won't see the DHCP server in the T-Mobile device. The T-Mobile device will think it only has one device connected, i.e., the Pepwave WAN port.

One caution I would say is to make sure the WAN and LAN addresses on the Pepwave are different. You can probably figure what IP address range T-Mobile allocates and make sure your Pepwave LAN (i.e., its DHCP server) is set for a different range. I'm not sure what would happen if they're the same.

As for tethering a phone as for the WAN, the situation is much the same. I don't know how you connect to the phone. Does the Wi-Fi ranger connect via USB? I don't know for sure but I assume it is acting as a DHCP client so I don't think there is a problem. I have a little GL.iNet router that can tether a phone for its WAN and that acts as a DHCP client. It also has a DHCP server for the LAN side just like a Pepwave etc.

[RKins]

What you didn't mention is why you need to control this. Most every router is the DHCP source for an IP address and they normally issue a Class C IP address in the 192.168.x.x. This is the private range of IP addresses that a router won't pass outside of the private network. The router translates the incoming IP addresses to it's private addresses.
So tell us the real concern plz.
One thing that stands out is the cell phone in the mix. Are you trying to use it as the DHCP device?
As far as I know the pepwave uses a SIM card (or 2) to connect to a tower and it emits wifi in the 192.168.x.x range.

[tetranz]

Originally Posted by RKins

What you didn't mention is why you need to control this. Most every router is the DHCP source for an IP address and they normally issue a Class C IP address in the 192.168.x.x. This is the private range of IP addresses that a router won't pass outside of the private network. The router translates the incoming IP addresses to it's private addresses.
So tell us the real concern plz.
One thing that stands out is the cell phone in the mix. Are you trying to use it as the DHCP device?
As far as I know the pepwave uses a SIM card (or 2) to connect to a tower and it emits wifi in the 192.168.x.x range.

Corley can answer for himself but I think he wants to use a Pepwave as the router for the LAN but use the T-Mobile home internet as the WAN for that Pepwave. That makes good sense considering the price of the T-Mobile service compared to price and limited choice of data plans for something like a Pepwave. It also makes sense to keep the Pepwave in the mix because the LAN then stays the same regardless of WAN. Nothing on the local devices needs to change if the WAN changes from T-Mobile to something else.

[Corley]

Thanks everyone for your input. When I was contemplating this arrangement, I was concerned that if I had multiple WAN sources, I only wanted one lan address range on the LAN side of things, but if the WAN sources were providing the IP addresses, then there would seem to be the possibility that I could get IPs assigned from one of multiple sources. Seems with no settings needed on my part, both the WIFI Ranger and the PEPwave are assigning the LAN side IP addresses, so this is not a problem at all.

I will say that after playing around with these devices for a while, I would NEVER recommend the WIFI Ranger to anyone, when the PEPwave is so superior in it's user GUI, and capabilities. When I watch how multiple sources are used in a load sharing experience, the WIFI Ranger does load share, but there is no overall speed improvement, whereas the PEPwave actually give better overall throughput in a load-sharing mode. The PEPwave menus make a lot of sense to this novis, whereas the WIFI Ranger is a but of a mystery in some regards.

Further, the WIFI ranger had a couple of hiccups that I could not get out of (probably user induced), without connecting a PC via ethernet. Using only WIFI to try to get logged in, would not work at all. No amount of resetting using their special "weird" method of resetting, would actually fully reset the router. It works, load shares, but with no throughput improvement at all, whereas with the PEPwave, I did see a speed improvement. (Not a lot, but about 10-20 %.

As to why the tethered cell phone usage, on our last motorhome trip, I used two cell phones for internet access. (Both my wifes and mine on Visible for their truly unlimited data,) I started out with the WIFI Ranger, but when it locked up and would not fully reset without cable connected PC to get back into it, and my Laptop did not have said ethernet connection, I quickly gave up on it and bought a PEPwave, which worked flawlessly. Since I rarely need/use my cell phone, I just left it tethered to the router, (both WIFI Ranger and PEPwave supply a USB port that both acts as a data port and a charge port), and then during some heavy cell tower load periods, I would connect my wife's phone via wifi, and share the load between the two cell phones. We were always able to stream as much as we wnated using that configuration.

However, since my Century Link home internet is so poor (we don't live close to their servers) I thought that I'd try the T-Mobile home internet option, which I understand we could also take on the road when we travel. This would give us two different carriers, with the hope that when one was busy or out of range, the other might be good. So the experiment was on. And for the most part, T-Mobile has provided much better speeds than Century Link, however, at about 8:00am - 9:00am, and again around 4:00 - 5:00pm the cell tower must be overloaded because performance drops off to almost nothing. No problem I thought, If I supply a second WAN source via my cell phone and Visible cell service, (really Verizon I guess), I might be able to live with the problem. No Dice, Visible cell service at those same peek usage times is just like T-Mobile, IE, it sucks too. For about 22 hours a day, both are great at my house, weekends are great all the time, so I surmise perhaps some businesses are moving large data files at those times.

To summarize, this was an experiment, I will be returning the T-Mobile gateway and dropping that since it is not suitable for my home internet, and I will go back to the two Visible cell phones and the PEPwave router in the motorhome for travel. Until something better comes along. I might just go for a HiBoost for those weeker locations.

Thanks again for your responses.