Posted: Tue May 16, 2017 17:52 Post subject: PPTP point to point no data passing over tunnel
I have been using PPTP point to point between WNR3500L routers for years without problem. Currently the two routers are running 14929 and 25648. If I ping the router LAN address from the other router the ping works fine.
Recently I had an issue with one router and decided to move forward and replace it with a WNDR3700V1 (Atheros) running build 31924. The problem I had was that when the two VPN tunnels connected pings from either to the other would just hang up. However I did manage to connect my laptop over the tunnel and it worked fine. So the problem seems to be within the two routers in the point to point connection.
I've had a look at the forum and the only potential entry which might shed light hasn't any response
Last edited by px03afk on Wed Jul 26, 2017 13:27; edited 1 time in total
After my abortive attempt to change one end to a WNDR3700 I went back to my tried and test solution. Today I replaced the other end with a WNR3500L-V2 running v3.0-r2752M(07/17/15)kong and had exactly the same problem as in my original message.
I've looked at routing tables, checked all the settings and I can't find anything which would explain what is happening.
The two tunnels get established as I would expect but I can't ping either way. So, there has to be something which is upsetting the routing from both ends. As soon as I replaced this end with the original WNR3500L VPN started working again.
Would appreciate some guidance on how to get to the bottom of this.
Not entirely sure what you mean by three networks. Each router is configured in the same way with the remote address and remote LAN in the Client and a unique gateway and client address range in the Server. More importantly it works fine with the orignal two routers. The difference is that with either end changed to a different build the tunnel still gets created, it just won't pass any data.
I'm still hoping somebody might be able to point me in the right direction to overcome my problems.
I've once again used a router with a later build and one major difference I've noticed is withrespect to the iptables data on BOTH routers when one of them is the later build.
When everything is working OK both routers have entries in the FORWARD iptables chain which read:
When the newer version is installed the newer build becomes:
ACCEPT 0 -- 192.168.100.0 anywhere
ACCEPT 0 -- anywhere 192.168.100.0
In other words there is no mask on the address.
Unfortunately I don't know enough about iptables to be sure whether this matters or not and for that matter I'm not completely sure how to correct the table if it really is the problem.
