the topology likes as following.
vpn gateway -- internet -- router -- firewall(Cisco 7206) -- backbone(C 7609) <--GRE--> branch office(C6509).
If the branch office wants to connect internet, and then the packet need to travel above path. to establish VPN, it is also same path.
however, at the particualr web site (www.naver.com), the web connection through VPN is ok. however, the connection is not using VPN is failed.
In this case, Do we consider that it is MTU issue between backbone and branch office?
my opinions is that VPN consume large size then general access. So, VPN is ok, then other can be able to access as well.
because, there is added VPN overhead and GRE header when the connection made by VPN.
but, actually, it can't not, Even if the web site connection via VPN is successful, but general access is not working well.
So, Do we have another solution for that?