Externally unaccessible "97." IP addresses
w4sm
Newbie

I have two Verizon cell modems at different locations in Virginia, each running in 3G mode and connected to NetCams.  I use a DDNS service to keep track of the dynamic IP addresses so that I can externally access the cameras.  In the last week or so Verizon has been randomly using IP addresses that start with  "97."   These look like real external IP addresses (they don't start with "10." , "172." , or "192" like internal reserved addresses) but they cannot be accessed from outside of the system.  My modems reset (power off/on) twice a day and sometimes they come back up with an externally accessible "75." IP address, but much of the time I get an unaccessible "97" address.

Is this how things are going to be from now on?  Is this a ploy to get me to spend $500 for static IP addresses? 

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Re: Externally unaccessible "97." IP addresses
John_Getzke
Champion - Level 1

Yes.  That is how things are going to be.

and Yes.  You can reboot until you randomly pull a good IP or pay for the static to correct the problem.

I had read articles on this subject in the past but my links are escaping me at the moment.  A quick google search is also returning nothing useful. Perhaps another forum member will correct me if I'm wrong.

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Re: Externally unaccessible "97." IP addresses
evdotech
Contributor - Level 1

The issue you are having is only with the Hybrid Modems, you should be OK with a 3G MODEM only.  with the hybrid modems even if they are locked into 3G you will have to reboot until you get a good address or pay the $500 bucks to verizon for a static IP address.

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Re: Externally unaccessible "97." IP addresses
w4sm
Newbie

evdotech wrote:

The issue you are having is only with the Hybrid Modems, you should be OK with a 3G MODEM only.  with the hybrid modems even if they are locked into 3G you will have to reboot until you get a good address or pay the $500 bucks to verizon for a static IP address.

Umm...no.  that is not correct.  One of my modems is a hybrid locked in 3G.  The older is a standard 3G modems.  Both have given sporadic "97." addresses at about the same rate.  For the last two days this has not been a problem and both have been reporting functional "75." addresses on reboots.... don't know how long this will last, though. 

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Re: Externally unaccessible "97." IP addresses
John_Getzke
Champion - Level 1

@w4sm,

You might want to speak with a VZW rep for a more official explanation on this one.

The order to which VZW devices display and provide public IP addresses is nothing that we can control or configure.  We are at the mercy of VZW to allocate thier public facing IP addresses to our devices.  I assume there is some kind of network pool of addresses that are available at any given time.  When a device shuts down it drops its old IP and negotiates a new one from VZW the next time it connects, this is how DHCP works on home routers.  When all the public IP's are taken up then .97 addresses are distributed to fill in the remaining gap of users.  We can only assume this problem will get worse as more devices are added to VZW and those public IP's have to spread across more devices. 

We already know that public facing IP addresses are an issue on all 4G LTE devices due to the network technology that is used for that network.  VZW may be trying to protect its remaining public IPv4 addresses for those who are willing to pay the extra $$$.  Perhaps this situation will get better when VZW starts providing IPv6 addresses to all thier devices instead of IPv4.

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Re: Externally unaccessible "97." IP addresses
w4sm
Newbie

John,

I believe you are correct in that VZW uses the "97." addresses as "gap fillers," perhaps primarily when they are having system problems, but I suspect, as you say, that they will get used more and more until we go to IPv6.  For the last 6 days I've been getting only functional "75." addresses on both modems, but I don't know how much longer that will last.  It's also unclear why the "97." addresses aren't functional since they are not reserved internal addresses. 

I will call a VZW rep. if/when the situation recurs, but I won't be optimistic that I'll get an informed answer, given some of the comments I've read on other forums about this and similar issues.  When 4G LTE comes to my area, I may spring the $500 for static IP's (it's my understanding that you can get multiple ones in your name after paying the one-time fee), since the "75." addresses aren't available with 4G (unless you go with a static IP, you get only non-functional internal "10." addresses with a 4G mode modem).

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