SmartSDR for iOS VPN Issues

Rob Fissel

So an interesting problem that I've been (seemingly randomly) facing when using SmartSDR for iOS over a VPN. Using either L2TP or PPTP on my iPad pro/iPhone at work (FIOS ISP, WatchGuard firewall/AP) or iPad Pro from my iPhone hotspot (LTE), I've had no issues connecting on both an iPhone 6 and iPad Pro.

I went  to connect to connect via both L2TP and PPTP from our club meeting's WiFi connection at the Elks club. No idea who the ISP is. The Flex shows up during discovery correctly, but when I click to access the Flex, it goes back to the "you are currently not connected Tap here to connect." Same issue on both iPad and iPhone.

On a Cablevision DOCSIS3 connection at a family weekend house, L2TP or PPTP will present me with the Flex at the discovery screen correctly. However, when I go to connect to it, I get the same issue as above. Just sits at the connection screen. I thought it might be the router with a UDP packet handling issue, so I swapped out for a newer Netgear router, which didn't resolve the problem. This problem occurs on both iPhone/iPad. 

Here's the kicker. We have no cell service at the family weekend house, so I put in an AT&T Microcell a few years back. If I disconnect from the WiFi, and move over to the microcell connection for data, and VPN back home using either L2TP or PPTP, the app works as expected, connecting to the radio just fine. The Microcell is using the same internet connection for it's backhaul, connected to the router via ethernet. 

Really scratching my head on this one...

KY6LA_Howard

Best guess is that some of the ISP are blocking the required VPN ports and possibly he AT&T microcell is tunneling those ports around the ISP.

Rob Fissel

Wouldn't that prevent me from establishing a VPN connection? I have no issues VPN'ing back to my home network, and being able to see things on the LAN, including the Flex on the discovery splash page. I can also see and pull from my media server as well. 

KY6LA_Howard

Not really..

For example SoftEther uses UDP Port 500, 1701 and 4500

So if the ISP Passes those ports then you will have a VPN connection

However SSDR uses ports which normally but not always tunnel through the VPN

- Commands: TCP via port 4992
- Data (FFT, Audio etc.): UDP 4991
- Discovery: UDP 4992 (via broadcast)

So if the ISP is blocking the SSDR ports or they are being used for some other process then it would likely mean that although you have a VPN you do not have SSDR

Rob Fissel

Thanks for this port info, Howard. I suppose it's also worth noting that I can connect to SSDR on a Win7 laptop using Softether from either of these connections.

KY6LA_Howard

That is even more curious information. Maybe a super network guru might have a better answer.

WX7Y

I have the exact same issue, my network circumstance is different but results are the same.

I have 2 networks from different ISP's plus my Verizon Hot spot.
I have my Softether VPN on network 1 where my Flex 6700 is located, if I connect to my network 2 with my IPAD / IPHONE running through the VPN to network 1  I see the FLEX but it won't connect BUT my laptop will connect and work perfectly connected to Network 2 and VPN back to the FLEX. 

If I change on my IPAD / IPHONE / Laptop to my Verizon hot spot and connect back to my VPN I can use the Flex 6700 just fine. 

Network 2 does have a WAN IP NAT forwarded to my location which I have not ruled out as the problem but it does not filter any ports in the current configuration. 

Still makes me really wonder why my Laptop works but the IOS stuff doesn't.

Thanks
Bret
WX7Y

WX7Y

I can use the windows VPN client or the softether client both work great on Network 2

Rob Fissel

A friend sent me an email after seeing this post, which text I will post below. I plan on trying to see if this is the issue when I'm back at the family home in two weekends...

Is it possible that the networks you are having trouble with have the same private subnet on both ends? (192.168.1.x for example)? I've seen that cause issues.

I know this is the case for the family home, who's subnet is 192.168.1.x, just like my home network. Since I don't always have control over the subnet on all the WiFi AP's that I connect to (Elk's Club for meetings for example), the easiest way would be for me to change my subnet of my home network to a less conventional one. I'll give this a shot and report back. I'll be away this weekend in Long Island, where the family router there is on a 192.168.1.x subnet as well...

Rob Fissel

Paul, 

This is getting a little above my paygrade, so not totally sure. Others seem to think that because softether is using HTTPS tunneling on port 443 that it may be different than using a standard L2TP or PPTP VPN. I'm no expert on this stuff, so I can't comment with any authority. 

Rob Fissel

Thanks, Paul. 

Considering I've encountered this issue on 2 of the 4 WLAN AP's I've used SSDR for iOS on, I'm surprised more aren't encountering this issue. Then again, it could just be bad luck for me...

WX7Y

Well I think I got it fixed, I am pretty sure it was that the network that the FLEX / VPN are on needs to have a differant subnet then the one your logging in from.
So if you change the IP range on your local router that the FLEX / VPN server are on to say 192.168.12.1 
and the other subnet is say 192.168.1.1  it should work, MINE DOES.

Thanks to all those who made comments it helped me get mine fixed anyway
73's
Bret
WX7Y

Rob Fissel

BTW, the credit for the subnet suggestion goes to Dave, WO2X. 

I'll begin the arduous process of going to 192.168.10.x tonight on the home LAN. Ugh, all the port forwarding rules and static IP assignments..... Anything to get SSDR for iOS up and running!

Rob Fissel

Just a quick update. Changing the home networks subnet to 192.168.12.x has resolved the remote issue for me. I'm back at the location that caused this issue in the past, and can now succesfully VPN back to the home network and connect to the Flex with SmartSDR for iOS.