Mikrotik VPN Site to Site

RouterOS General
1

Hello,

I have the following network diagram:
Two locations (datacenter) connected through Mikrotik routers with VPN Site 2 Site connection configured with IPsec and on each router client to site l2tp VPN connection. I will present this with different IPs just to make an idea.
Site 1 : WAN: 80.80.80.25
LAN : 192.168.2.0/24 Gateway:192.168.2.1 (lan router IP)
Site 2 : WAN: 81.81.81.25
LAN : 192.168.5.0/24 Gateway: 192.168.5.1 (lan router IP)

VPN Site 2 Site IPsec connection shows that is established.
client to site l2tp VPN connection is working on both routers.
NAT for both networks is created on the routers.
Firewall rules are the same on both routers.

If I’m connected on VPN on Site 1 I can access everything from Site 2 and Site 1 (ping is working , web services is working) but after a few minutes after connection I can only ping on devices but I can’t connect on their web interfaces (ILo’s interfaces, web servers a.s.o.).
If I’m connected on VPN on Site 2 I can only access devices from Site 2, not the ones from Site 1.

In both cases the VPN connections (site-to-site, client-to-site) are always up and never goes down.

Do you have any idea why I’m having this behavior ?

Thank you !

2

Ask your company IT staff.

3

What you describe is really strange. I have seen cases where any connection becomes impossible after some time of silence and these have a perfectly logical explanation, but I hear for the first time that ping remains possible but normal connections don’t.

At the moment I can only imagine some load distribution rules to come into play. So post anonymized exports first. If that is not enough, it will require some packet sniffing to find out.