Webgui empty response through vpn

topperblues

Hi to all,
I have configured pfsense as openvpn client.
I use this VPN to access pfsense console and pfsense webgui, i can access to pfsense via ssh but when i try to access webconfig i get redirect from http to https, the browser alert for my fake ssl certificate and then empty response.
If i change the protocol from https to http i can open web config but it's really really slow (sometimes i get timeout) when other sites on the same vpn are not slow.

curl https:

curl https://84.8.9.20/ -Lvk
*   Trying 84.8.9.20...
* TCP_NODELAY set
* Connected to 84.8.9.20 (84.8.9.20) port 443 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
* Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH
* successfully set certificate verify locations:
*   CAfile: /etc/ssl/cert.pem
  CApath: none
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
* TLSv1.2 (IN), TLS handshake, Server hello (2):
* NPN, negotiated HTTP1.1
* TLSv1.2 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
* TLSv1.2 (IN), TLS handshake, Server finished (14):
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
* TLSv1.2 (OUT), TLS change cipher, Client hello (1):
* TLSv1.2 (OUT), TLS handshake, Unknown (67):
* TLSv1.2 (OUT), TLS handshake, Finished (20):
* LibreSSL SSL_connect: SSL_ERROR_SYSCALL in connection to 84.8.9.20:443
* stopped the pause stream!
* Closing connection 0
curl: (35) LibreSSL SSL_connect: SSL_ERROR_SYSCALL in connection to 84.8.9.20:443

Routing:

...
84.8.9.0/24	84.8.9.1	UGS	220	1500	ovpnc2	
84.8.9.1	link#12  UH	0	1500	ovpnc2	
84.8.9.20	link#12	UHS	0	16384	lo0
...

OpenVpn firewall rules:

Protocol	SourcePort	DestinationPort	Gateway	Queue
IPv4 TCP	*	*	*	*	WANFIBRA	none

OpenVpn network:

server 84.8.9.1
network 84.8.9.0/24
pfsense ip 84.8.9.20
client used for testing 84.8.9.8

Do you have any idea why I can not access the web config and why is it so slow?
Thanks, bye bye!

topperblues

RESOLVED!
The problem was the MTU of VPN!
I had MTU 1500 but max of my openvpn machine was 1472.
I add
mssfix 1420
fragment 1472
mtu-test
to openvpn client config and all works!
Thanks!