Monday, August 5, 2013

Using static IP's on Verizon 4G

First a little background info on IP addresses and cellular data service. 3G data connections use publicly accessible valid internet IP addresses. While this is nice if you want remote access to a device it does needlessly use up increasingly valuable IPv4 addresses. When carriers rolled out their next generation 4G service they switched to using private 10.x.x.x networks and NATed the traffic out to the internet somewhere within their network. It is possible to get publicly accessible static IP's from Verizon but they don't make the process very easy.

Requesting static IP's

I am using Verizon 4G service with Cradlepoint routers as a backup internet connection at my remote offices. I wanted to use static IP addresses so I could get access to these offices if the primary internet connection went down. We have a Verizon business sales rep and he was the person that handled our static IP request. Verizon charges a one time $500 dollar fee to add static IP's to your account. First step was to authorize the one time $500 charge. My accounting department handled that and then my Verizon sales rep sent the request somewhere deep into the bowels of the Verizon bureaucracy. A month later we were approved. Next someone from Verizon called to ask what 'sub-group' or 'level' we wanted these static IP's to be attached to. It took a while on the phone to figure out what exactly they were asking. Turns out we have our Verizon devices setup in two different groups. One group is devices with phone and data service and the other group is data only (things like iPads, hotspots or Cradlepoints). So we applied the static IP's to our data only group of devices. From the conversation I had on the phone with this Verizon person my understanding is that we would need to pay $500 bucks for each group of devices.

Assigning static IP's to 4G devices

It would be really nice if there was some sort of website to assign static IP's to devices but sadly there is not. The process for attaching a static IP to a certain device is to e-mail your Verizon business sales rep the device IMEI and/or the phone number assigned to the device. The sales rep then handles assigning the static IP and will e-mail back the static IP address once one has been assigned to the device.

Configuring 4G devices to use static IP's

This is where information got really nebulous. I asked my Verizon sales rep if I needed to do any configuration to my Cradlepoint router for the static IP. He said "nope, it should just work". Well that is definitely not the case. To be able to use static IP's you must change a setting for something called the APN. The APN is used to identify what network the device should attach to. The ability to change the APN of a device varies depending on the carrier. My AT&T iPhone does not present any options to change that setting but this Apple knowledge base document shows the option does exist. On Cradlepoint routers this option is easily accessible because it is a somewhat common thing to modify on those devices. The APN menu location on Cradlepoints depends on the device but it is usually under either modem settings or the Connection Manager.
Now what should the APN be set to for Verizon devices? Well this took a bit of searching. I found a few blog posts that said it should be set to "mw01.vzwstatic". I tried this and the modem kept dropping it's connection with an error saying carrier rejected. So after more searching I found this list of Verizon APN's:

1. ne01.vzwstatic (NorthEast)
2. nw01.vzwstatic (NorthWest)
3. so01.vzwstatic (South)
4. mw01.vzwstatic (MidWest)
5. we01.vzwstatic (West)

The correct APN depends on where you are in the country. I did not find any more specific information than this and since Texas spans a few different regions I wasn't exactly sure which one I should use. I took a guess at so01.vzwstatic and it turned out to be the correct one. After setting this option the Cradlepoint 4G modem cap restarted and it grabbed the correct static IP from Verizon. Success!

If you switch back to dynamic IP's you should use the APN "vzwinternet" or use the default setting for the device. I found once my device was assigned static IP service and I restarted the modem I could not use vzwinternet. Seems like the APN has to match whatever Verizon has assigned on their backend or they will reject the device.