OpenVPN site to site - Only traffic from pfsense boxes work

[viragomann]

@iago-op
The point is if the destination device itself is allowing the access from the remote network.

You can easily check this with pfSense. On the pfSense next to the device go to Diagnostic > Ping, enter its IP at host and try to ping. Should succeed.
Then change the source to OpenVPN and try again. Does this succeed as well?

[Iago OP]

@viragomann said in OpenVPN site to site - Only traffic from pfsense boxes work:

@iago-op
The point is if the destination device itself is allowing the access from the remote network.

You can easily check this with pfSense. On the pfSense next to the device go to Diagnostic > Ping, enter its IP at host and try to ping. Should succeed.
Then change the source to OpenVPN and try again. Does this succeed as well?

Thanks for your tip, but I've already checked that.

If I ping using either default, or OpenVPNclient the ping goes through

If I ping using LAN, it does not. The same as if I use a computer into the local LAN to do the end to end ping.

I also did another test. Try to open a webpage from my local computer (10.0.50.10) in a remote end machine webserver (10.0.111.200) while I debug with the pTop utility:

[viragomann]

@iago-op said in OpenVPN site to site - Only traffic from pfsense boxes work:

If I ping using either default, or OpenVPNclient the ping goes through
If I ping using LAN, it does not. The same as if I use a computer into the local LAN to do the end to end ping.

I asked to do that on the pfSense box next to the destination device, not on the remote box and not pinging the one of the pfSense boxes themself. You did already mention above that this is working.
So go on the server and ping any device in it LAN 10.0.111.0/24.

[Iago OP]

@viragomann said in OpenVPN site to site - Only traffic from pfsense boxes work:

@iago-op said in OpenVPN site to site - Only traffic from pfsense boxes work:

If I ping using either default, or OpenVPNclient the ping goes through
If I ping using LAN, it does not. The same as if I use a computer into the local LAN to do the end to end ping.

I asked to do that on the pfSense box next to the destination device, not on the remote box and not pinging the one of the pfSense boxes themself. You did already mention above that this is working.
So go on the server and ping any device in it LAN 10.0.111.0/24.

Yep, the scenario is:

ClientsLAN1 -10.0.111.0/24- Pfsense1(server) [ OPENVPN ] Pfsense2 --10.0.50.0/24- ClientsLAN2

Everything between Pfsense1(server) and LAN2 works ok (pfsense and clients)

The same, everything between pfsense2 and LAN1 work ok.

The problem is when I try LANCLIENTS1 to LANCLIENTS2

Is weird, could be a bug in pfsense? Should I miss some rules ?

[viragomann]

@iago-op
Fine now you're showing pings on both site with default settings. Still no use.

[Iago OP]

@viragomann said in OpenVPN site to site - Only traffic from pfsense boxes work:

@iago-op
Fine now you're showing pings on both site with default settings. Still no use.

@viragomann said in OpenVPN site to site - Only traffic from pfsense boxes work:

I asked to do that on the pfSense box next to the destination device, not on the remote box and not pinging the one of the pfSense boxes themself. You did already mention above that this is working.
So go on the server and ping any device in it LAN 10.0.111.0/24.

On the server, I can ping the LAN devices without problems

Thanks for you help mate

[viragomann]

@iago-op said in OpenVPN site to site - Only traffic from pfsense boxes work:

On the server, I can ping the LAN devices without problems

Dude! I'm not in doubt of that. Mentioned above. But what do you get here if you simple change the source to OpenVPN???

[Iago OP]

@viragomann said in OpenVPN site to site - Only traffic from pfsense boxes work:

@iago-op said in OpenVPN site to site - Only traffic from pfsense boxes work:

On the server, I can ping the LAN devices without problems

Dude! I'm not in doubt of that. Mentioned above. But what do you get here if you simple change the source to OpenVPN???

It also works

In the server side, I can ping from openVPN to CLientLAN1 without problems.

On the client side, the same, pings between OpenVPN interface/lan and the ClientsLAN2 work fine.

It just only fails on the LAN1 to LAN2 communications :S it's weird right?

[viragomann]

@iago-op
Well. So the device is not blocking the access.
So let's take a look into the routing tables of both pfSense boxes.

[Iago OP]

@viragomann said in OpenVPN site to site - Only traffic from pfsense boxes work:

@iago-op
Well. So the device is not blocking the access.
So let's take a look into the routing tables of both pfSense boxes.

Client:

I can see the route 10.0.111.0/24 going through 10.0.18.1 which is the OpenVPN interface

On the server side:

I also see the correct routes:
10.0.50.0/24 by 10.0.18.2

(I also have in here a server2 which i creted trying to solving this problem with a new server, but I I'm not using it right now)

Thanks !!

[viragomann]

@iago-op
Seems to be well.

Static public IPs should better be hidden when you post a screenshot in the web. The PPPoE may change, but I don't know of the other one.

Interestingly the client show no use of the route. Maybe if you try a connection from the clients LAN.

Yes, absolutely weird.
We had already issues with VPNs that won't work while all seems fine. After pulling it down and start from scratch it mostly worked.

You may try more investigations with the packet capture tool, but I cannot think of any further reason.

Only one thing are the firewall rules on OpenVPN interface. You didn't post a screenshot. So consider for pinging you have to allow ICMP or any protocol. If you have only TCP, ping will not work.

[Iago OP]

@viragomann said in OpenVPN site to site - Only traffic from pfsense boxes work:

@iago-op
Seems to be well.

Static public IPs should better be hidden when you post a screenshot in the web. The PPPoE may change, but I don't know of the other one.

Interestingly the client show no use of the route. Maybe if you try a connection from the clients LAN.

Yes, absolutely weird.
We had already issues with VPNs that won't work while all seems fine. After pulling it down and start from scratch it mostly worked.

You may try more investigations with the packet capture tool, but I cannot think of any further reason.

Only one thing are the firewall rules on OpenVPN interface. You didn't post a screenshot. So consider for pinging you have to allow ICMP or any protocol. If you have only TCP, ping will not work.

Yep, Thanks for the remainder of the public ips :)

the OpenVPN firewall rules are allow all for all protocols. I just make sure because of this tests specifically with ping.

There is any way to debug this kind of problems? Like a traceroute which indicates what interfaces goes through a packet?

Tank you again mate

[Iago OP]

@iago-op said in OpenVPN site to site - Only traffic from pfsense boxes work:

@viragomann said in OpenVPN site to site - Only traffic from pfsense boxes work:

@iago-op
Seems to be well.

Static public IPs should better be hidden when you post a screenshot in the web. The PPPoE may change, but I don't know of the other one.

Interestingly the client show no use of the route. Maybe if you try a connection from the clients LAN.

Yes, absolutely weird.
We had already issues with VPNs that won't work while all seems fine. After pulling it down and start from scratch it mostly worked.

You may try more investigations with the packet capture tool, but I cannot think of any further reason.

Only one thing are the firewall rules on OpenVPN interface. You didn't post a screenshot. So consider for pinging you have to allow ICMP or any protocol. If you have only TCP, ping will not work.

Yep, Thanks for the remainder of the public ips :)

the OpenVPN firewall rules are allow all for all protocols. I just make sure because of this tests specifically with ping.

There is any way to debug this kind of problems? Like a traceroute which indicates what interfaces goes through a packet?

Tank you again mate

I think I have a clue. Revieweing the logs for each interface I found that it's using ipv6 routing in the client side. While on the client side, openVPN is configured only to use ipv4

Maybe cloud be this ?

[viragomann]

The routing protocol setting is at the bottom, you can check IPv4 gateway only there.

[Iago OP]

@viragomann said in OpenVPN site to site - Only traffic from pfsense boxes work:

The routing protocol setting is at the bottom, you can check IPv4 gateway only there.

In one side was ipv4 but in the other side was both. I changed to ipv4 only but this not fixed the problem.
as I'm expected.

I keep investigating. If I do a packet capture on the openvpn interface in the client while a ping is in course, it does not register any packet.

[viragomann]

@iago-op said in OpenVPN site to site - Only traffic from pfsense boxes work:

There is any way to debug this kind of problems? Like a traceroute which indicates what interfaces goes through a packet?

As mentioned, you can do some packet capture on the both pfSense boxes.
The VPN connection is like a network wire into the other site. Each site has a virtual interface. Here you can sniff the traffic.

So for instance you try to ping from a clients LAN device to one on the remote site, you can trace the ping packets with packet capture on all the involved interface: clients LAN and OpenVPN, servers OpenVPN and LAN. So you can check where it stops.

But I don't understand what your first ping attempt show. It works from client to the servers LAN IP whith default, which means the source is the client OpenVPN IP. But it doesn't work if the source is the clients LAN IP, even if there is the correct route on the server for that subnet.
Your routing tables screens seem to be incomplete, but I guess, there will not be another route overlapping the clients LAN.

[Iago OP]

@viragomann said in OpenVPN site to site - Only traffic from pfsense boxes work:

@iago-op said in OpenVPN site to site - Only traffic from pfsense boxes work:

There is any way to debug this kind of problems? Like a traceroute which indicates what interfaces goes through a packet?

As mentioned, you can do some packet capture on the both pfSense boxes.
The VPN connection is like a network wire into the other site. Each site has a virtual interface. Here you can sniff the traffic.

So for instance you try to ping from a clients LAN device to one on the remote site, you can trace the ping packets with packet capture on all the involved interface: clients LAN and OpenVPN, servers OpenVPN and LAN. So you can check where it stops.

But I don't understand what your first ping attempt show. It works from client to the servers LAN IP whith default, which means the source is the client OpenVPN IP. But it doesn't work if the source is the clients LAN IP, even if there is the correct route on the server for that subnet.
Your routing tables screens seem to be incomplete, but I guess, there will not be another route overlapping the clients LAN.

I've made some testing today, and I found that I can ping from my local client computers to the OpenVPN gateway on the other end. (and in the same end too)

Lets say I'm in the side of pfsense box 2 (10.0.50.1) with my IP: 10.0.50.10.
This end of the tunnel gets IP 10.0.18.2 (10.0.18.1 for the other end)

I can ping both of these openvpn interfaces no problem from the local machine

But cannot ping the remote LAN computers (10.0.111.0/24)

So there is a problem routing between openvpn interface 10.0.18.2 and the LAN network 10.0.111.0/24
But I cannot find the reason why this happens. The routing table looks good, there is an entry for this subnet in it:

And the firewall rules for the LAN allow incoming traffic from 10.0.18.0/24 and 10.0.50.0/24:

Should I consider reporting a bug for this issue? There is any public board to fill in a bug report?

Thank you @viragomann , you were very helpful :)

[viragomann]

@iago-op
One thing I noticed. You are talking about a site-to-site VPN, but you have a /24 tunnel network.
A s2s should have a /30. So there is only one IP for the server and one for the client. I'd suggest to change this.

[Iago OP]

@viragomann said in OpenVPN site to site - Only traffic from pfsense boxes work:

@iago-op
One thing I noticed. You are talking about a site-to-site VPN, but you have a /24 tunnel network.
A s2s should have a /30. So there is only one IP for the server and one for the client. I'd suggest to change this.

Thanks mate for the tip.

Unfortunately, the problem persists. I can ping the remote end of the tunnel endpoint but cannot ping the LAN behind it.

It's driving me nuts. I've tested an IPSEC tunnel and works fine. I'm going to give-up this openvpn efort. Maybe I can help reporting this issue to the pfsense develoepers... I don't know

[Iago OP]

I finally get it to work!!

It was a problem with a configuration of an IPSec tunnel that I had previously on one end.

It turns out that although it was disabled, it has configured the subnet 10.0.18.0/24

So I assume that this configuration is not supported and having the same subnet on these different services could cause the issue.

Thanks @viragomann for your help :) I really appreciate mate