PGEE 2018 [closed]

Question

A firewall is to be configured to allow hosts in a private network to freely open TCP connections and send packets on open connections. However, it will only allow external hosts to send packets on existing open TCP connections or connections that are being opened (by internal hosts) but not allow them to open TCP connections to hosts in the private network. To achieve this the minimum capability of the firewall should be that of

1. A combinational circuit
2. A finite automaton
3. A pushdown automaton with one stack
4. A pushdown automaton with two stacks

Comments

please refer below link for discussion 

https://gateoverflow.in/3451/gate2007-it-18