apt-cache search synergy
apt-get install synergy

/etc/synergy.conf (create)

section: screens
   host1:
   host2:
end
section: links
   host1:
        right = host2
        host2:
        left = host1
end

shell> synergys -f -c /etc/synergy.conf  (host1)
shell> synergyc -f 192.168.4.3 (host2)