topic Re: Teamviewer access on EE4G in Archived Posts

Teamviewer access on EE4G

benphillips — Mon, 24 May 2021 15:12:58 GMT

Hi,

We have had to put in a 4G broadband connection in an office because the standard landline broadband speeds are woeful. The 4G speeds on EE are much better and the internet connection is fine across the office. However, we have Teamviewer installed on some of the machines in the office to allow remote access, and Teamviewer does not detect an internet connection. We also have AnyDesk installed on one machine, and this constantly has the message "Trying to connect to network". It would appear that something is blocking these connections. Can anyone shed any light? We are using a Zyxel router rather than an EE router and so could make changes if necessary.

Any advice greatfully recieved!

Re: Teamviewer access on EE4G

XRaySpeX — Mon, 24 May 2021 16:10:46 GMT

You may be up against a limitation of EE's mobile network. The EE mobile network uses Carrier Grade NAT (CGNAT) resulting in a double NAT, which means that you don't get your own public IP address but share it with other users. So you can't be uniquely id'ed on the Net & therefore your LAN cannot be addressed from outside for unsolicited accesses. This is unlike fixed BB.

If that's the case there is nowt you can do to avoid it.

Re: Teamviewer access on EE4G

benphillips — Mon, 24 May 2021 16:39:22 GMT

Thanks XRaySpeX.

The machines running Teamviewer and AnyDesk are inside the network and are just not able to connect the the relevant services outside the network via the 4G connection. That may be the way that these connections are implemented and they need to be able to find a path back inside the local network which will be scuppered by CGNAT.

I'll see if I can get more info from Teamviewer and AnyDesk, but appreciate your response.

Anyone else have any experience with Teamviewer or AnyDesk across EE 4G?

Thanks.

Re: Teamviewer access on EE4G

XRaySpeX — Mon, 24 May 2021 18:01:50 GMT

Solicited responses to requests inside the LAN should be OK & not hindered by CGNAT.

Re: Teamviewer access on EE4G

benphillips — Tue, 25 May 2021 06:53:08 GMT

Thanks XRaySpeX.

My understanding was that Teamviewer was able to deal with CGNAT as it initiates a connection from client software running on the remote machine.

Also, our router is only connecting with an IPv6 address and not an IPv4 address. Does EE use CGNAT for IPv6 addresses?

Does anyone know if it is possible to get an IPv4 connection to EE on 4G. Perhaps this is the cause of the connection issues on Teamviewer and not CGNAT.

Is anyone at EE able to provide any insight into this?

With thanks.

Re: Teamviewer access on EE4G

James_B — Tue, 25 May 2021 07:16:01 GMT

Hi @benphillips,

Welcome to the EE Community. 🙂

I'd recommend contacting the software developer for support. They'll be able to confirm if their product is compatible with CGNAT and if they have a version available which is IPv6 ready.

James

Re: Teamviewer access on EE4G

benphillips — Tue, 25 May 2021 12:43:46 GMT

Thank you for your input James.

I wish it was that easy to get information from Teamviewer. I have contacted them directly but not had any definitive answer as to whether Teamviewer clients can operate successfully from behind CGNAT. From my understanding it can, so I can't see any particular reason why Teamviewer clients can't connect to the Teamviewer network.

I have tested with AnyDesk too, and get the same issue: AnyDesk is unable to connect to the AnyDesk network, and so not remote access to machines in the office is currently possible. It is something to do with the the EE 4G network, but I can't see what. I have searched EE's forums but not found anything that provides any help.

Has anyone else come across this issue: unable to access machines remotely that are connected through EE 4G? I'm tearing my hair out here!

Re: Teamviewer access on EE4G

James_B — Tue, 25 May 2021 13:26:43 GMT

Hi @benphillips,

I don't have any personal experience with the applications you are using. Have you checked you are using the latest versions? It could be that you are using an older version that doesn't include IPv6 support.

If you are, I would recommend reaching out to the developers. I can see TeamViewer has its own community at community.teamviewer.com/English/.

Hope this helps.

James

Re: Teamviewer access on EE4G

XRaySpeX — Tue, 25 May 2021 14:34:12 GMT

It might be an EE IPv6 issue. EE has introduced IPv6 on its mobile network, but it doesn't fall-back to IPv4 nicely. Can you change the Profile/APN on your EE devices to APN Protocol = IPv4 only?

Re: Teamviewer access on EE4G

benphillips — Tue, 25 May 2021 15:06:44 GMT

@XRaySpeX

Thanks for the further suggestion.

The router is set to connect with IPv4 and IPv6, but it doesn't get an IPv4 address and shows as disconnected. It only shows as connected with an IPv6 address. If I change the APN settings on the 4G router to connect with IPv4 only, then there is no internet connection, suggesting that EE does not support IPv4 at all!

Argh!

Re: Teamviewer access on EE4G

XRaySpeX — Tue, 25 May 2021 17:24:04 GMT

Can't believe that! Many mobile router users have successfully switched down to IPv4 when they had an issue when it was IPv4/IPv6 combined.

Re: Teamviewer access on EE4G

mikeliuk — Tue, 25 May 2021 15:18:56 GMT

Hi @benphillips ,

Would you be able to put that SIM into another router or phone to see if a different device gets an IPv4 address assigned by the service provide which shall not be named?

It doesn't sound correct to me that no IPv4 address is assigned. I would expect you to receive a 100.x.x.x address assuming it's a standard consumer SIM. I probably have no idea about business SIMs but I get the impression they may be assigned publicly routable IPv4 addresses but not statically assigned, until you are assigned something, you can't check either way.

Re: Teamviewer access on EE4G

benphillips — Tue, 25 May 2021 16:52:38 GMT

@XRaySpeX

"Can't believe that! Many mobile router users have successfully switch down to IPv4 when they had an issue when it was IPv4/IPv6 combined."

Quite right too! I changed the settings back to IPv4 only again, and this time got a connection with an IPv4 address. Perhaps I was a little impatient last time. With an IPv4 address, Teamviewer and AnyDesk clients can connect correctly. Your suggestion re it being an issue with EE having issues with falling back to IPv4 addressed would appear to be the case.

I thank you for your time and responses, and I am very grateful.

Re: Teamviewer access on EE4G

benphillips — Tue, 25 May 2021 16:54:03 GMT

@mikeliuk

As per my previous post, changing the APN settings to connect via IPv4 has worked this time. The router has got a 10.x.x.x address (it is an EE business SIM).

Thanks for your time and input.

Re: Teamviewer access on EE4G

XRaySpeX — Tue, 25 May 2021 17:25:56 GMT

Thanks! You're welcome 🙂 ! Glad I could be of assistance & it is now sorted.

Re: Teamviewer access on EE4G

mikeliuk — Tue, 25 May 2021 22:04:48 GMT

Hi @benphillips ,

Very glad you got that sorted.

I just wanted to flag for your attention that the 10.x.x.x range (i.e. 10.0.0.0/8) is a subnet reserved for private network usage and is used by many large enterprises for their own internal networks as it is one of the largest (if not the largest) such range reserved for such usage. https://en.wikipedia.org/wiki/Private_network

Therefore, in my personal opinion, the service provider should not be using IPv4 addresses within this range to assign to businesses as this could cause a misconfiguration of the network if the same range is used elsewhere within a business or enterprise. If there is any chance the network administrator is already using or may in the future choose to use IP addresses in 10.0.0.0/8, care must be taken when it comes to routing.

Hopefully this turns out to be a non-issue, perhaps if all other subnets are in the other private ranges. Good luck!

Re: Teamviewer access on EE4G

XRaySpeX — Wed, 26 May 2021 02:49:03 GMT

@mikeliuk : This is a non-issue.

@mikeliuk wrote:

Therefore, in my personal opinion, the service provider should not be using IPv4 addresses within this range to assign to businesses as this could cause a misconfiguration of the network if the same range is used elsewhere within a business or enterprise.

EE isn't & it won't cause issues on internal networks!

This 10.x.x.x IP is the external "public" IP assigned to the SIM device by EE's DHCP within its CGNAT regime.
EE is itself one of your many large enterprises using these 10.x.x.x IPs for their own internal networks behind the CGNAT.
Many other CGNAT'ing mobile networks will be doing the same thing; O2 for 1.
Even if the LAN behind the phone/router is using the same 10.x.x.x IP subnet they will not be confused or misconfigured. It's all taken care of by the local NAT translating an internal routing 10.x.x.x IP into an external EE CGNAT 10.x.x.x IP. I have had 2 fixed BB routing routers on the same 192.168.1.x subnet working seamlessly even if both of them give out IP 192.168.1.100, say, but to 2 diff devices. Same principle!
This 10.x.x.x IP is not the true external public IP (shared by CGNAT) seen by the rest of the Net. That may be gotten by WhatsMyIP type sites, not by looking in the About My Device settings.

Re: Teamviewer access on EE4G

mikeliuk — Wed, 26 May 2021 08:20:04 GMT

Making a note for people reading this in the future that Wiki summarizes the issue as follows:

"If an ISP deploys a CGN, and uses RFC 1918 address space to number customer gateways, the risk of address collision, and therefore routing failures, arises when the customer network already uses an RFC 1918 address space."

https://en.wikipedia.org/wiki/Carrier-grade_NAT

RFC 1819 may be found here: https://datatracker.ietf.org/doc/html/rfc1918

Edit: a particular risk is if the 192.168.0.0/16 subnet is too small for an office and 10.0.0.0/8 is used on the subnet which directly accesses the service provider's gateway.