Meraki MX IPsec over a PPTP Tunnel ?

[MerakiNovice]

Hello, 

We have a PPTP tunnel towards a datacenter we own, the tunnel is made in a router towards our datacenter, the Meraki is connected to that router and all of the internet is actually comin through that PPTP tunnel .

The Ipsec connects but doesn't learn any routes .. what might the problem be ? 

your help is highly appreciated 

Thanks 

[ww]

Are you talking about  the 3rd party vpn? https://documentation.meraki.com/MX/Site-to-site_VPN/Configuring_Site-to-site_VPN_between_MX_Applian...

It does not learn routes dynamically

[MerakiNovice]

No, its not a 3rd party VPN, but the internet that feeds the Meraki itself is a tunneled internet, so Meraki shoudn't have any idea about that .

Everything in the Meraki MX is just the usual configuration default settings .

[ww]

So your not learning routes in the autovpn? And on other sites  it works ?

Can you test mtu size from a client at the router 

ping www.meraki.com -l 1472 -f

[MerakiNovice]

Correct ! we can't learn the routes through the autovpn, and you are right about the MTU I went here just to get someone reaching this level, though .. the pptp tunnel handles 1450 Byte MTU that is correct, but I have used MRRU to increase the data that could be transmitted on the tunnel to 1600 Bytes, so I can easily ping packets with 1472 Byte size normally now .

Yet the issue is still the same we can't learn routes, I was thinking to change the MTU size by contacting Meraki but I don't have access to the customer's portal, and I think the mrru is enough to fix the issue over the pptp link .

What do you think ?

[ww]

I guess thats fine then.

Are you sure they setup the autovpn  routing  correct. Like bgp or select vlan to be in vpn.

[MerakiNovice]

Everything sure is correct, because if they use a different internet connection even cellular one, they just work fine . I don't even know where to troubleshoot .

To let you know the router making the pptp is a Mikrotik router .

The ping could go fine up to 1500 packet size