> So the password is sent from UCSD and compered with the password i put locally and if they identical then the data is processed ?
> one more thing i understand the data is sent from UCSD ... how often is it sent ?
> I dont see any advertisement here do i need to define something in the portal ?
> normal tunneling work well
Of course you need to have a gateway entry in the Portal. I.e. you need to have a subnet, and
a gateway with external address and that subnet defined.
The RIP packets are sent every 5 minutes.
When you can manually make a tunnel and ping the remote, but you do not receive anything including
RIP broadcasts, the cause often is a stateful firewall inside your internet modem/router.
It accepts replies to outgoing packets, but it does not accept unsolicited incoming packets.
This is designed as a security feature.
To use IPIP tunneling, your modem/router must be able to unconditionally forward protocol-4 traffic
to your gateway system. In advanced modem/routers you can forward a protocol, but usually it is only
possible to forward TCP and UDP ports. That is something different. It is useless to forward port 4,
you have to forward protocol 4.
When that cannot be done you can often set a "DMZ host" that is said to get all incoming traffic,
however there are examples of modem/routers where this does not work correctly. The DMZ host receives
all TCP and UDP traffic but not all other traffic (including IPIP).
It does receive (like any host) replies on its own IPIP traffic, but not the unsolicited incoming traffic.
When you have such a modem/router, and when it cannot be replaced (e.g. because your provider requires
you to use this modem/router), you cannot use IPIP tunnels.
Rob