hi
there is so much filtering going on in my country and I have manged to setup some VPN in my router and make a list of filtered IPs and a mangle rule to direct any request to these IPs to VPN route.
everything is working fine except that sometimes I just can`t connect with some applications or sites! even by making new mangle rule to direct all traffic from my phone or PC to VPN!
is there something else that I miss!
In the absence of any details: the typical reason why some sites are inaccessible are MTU discovery problems.
A typical pattern is that in a traffic sniff for the server’s IP address, you can see the SYN packet from the client, the SYN,ACK one from the server, and then the first ACK-only one from the client. Following that, either the first large packet from the client is retransmitted multiple times before the client gives up, or the first large packet from the server never arrives.
The remedy is to use a mangle rule to set some smaller mss value for TCP SYN packets (like 1200 bytes) and if that helps, find the largest value which still works.
If you use a bare IPsec VPN, there may be a less rudimentary solution - again, you gave too little information. Check my automated signature just below.