Changes

# Remove the rules in your '''INPUT ''' chain that are allowing all '''icmp ''' and '''ssh ''' traffic.# Change the '''default policy ''' on the '''INPUT ''' and '''FORWARD ''' chains in the filter table to '''DROP'''.# Remove the rules from the '''INPUT ''' and '''FORWARD ''' chains that are rejecting all traffic (we are now better protected by the ''default policy'').# Create a new chain named '''MYSSH ''' in the filter table. Refer to notes or other resources to learn now to name a chain.# Add a rule to the beginning of the '''INPUT ''' chain of your filter table that sends all '''ssh ''' traffic (i.e. tcp packets with destination port 22) to your '''MYSSH ''' chain.#* '''Note: ''' Use '''--jump o r''' or '''-j ''' (<u>not</u> --goto) to move to a target.# Add a rule to your '''MYSSH ''' chain to accpept accept all traffic on your virtual interface from '''192.168.X.0/24 ''' (i.e. your internal network).# Add rules to the '''end of the MYSSH chain ''' to drop all remaining '''ssh ''' connections, but to log these denied packets with log level 'info' and log prefix "DENIED BY MYSSH" before doing so.# Make a new chain named '''MYICMP'''.# Add a rule to the beginning of the '''INPUT ''' chain to send '''ICMP ''' ping packets to your '''MYICMP ''' chain.

# Add a rule to your '''MYICMP ''' chain that allows '''ICMP ''' packets coming in on your virtual interface from '''192.168.X.0/24 ''' (i.e. your internal network).# Add a rule to your '''MYICMP ''' chain that denies '''ICMP pings ''' originating with MAC address of your partner's machine.# Add a rule to your '''MYICMP ''' chain that denies '''ICMP pings ''' originating with IP address of your partner's machine.