>The answer is: None.
May I suggest a netstat -tulp to see listening services on this laptop ?
While outgoing connections can be discussed, incoming *should* be filtered.
Here some basic configuration for iptables :
*filter
:INPUT DROP [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -i lo -j ACCEPT
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -p tcp ! --syn -m state --state NEW -j DROP
-A INPUT --source
192.168.1.0/24 -p tcp --dport ssh -j ACCEPT
COMMIT