Routers on the Internet should be configured to discard any packets containing private IP addresses in the IP packet header. This isolation gives private networks a basic form of security as it is not usually possible for the outside world to establish a connection directly to a machine using these private addresses. As connections cannot be made between different private networks via the internet, different organizations can use the same private address range without risking address conflicts (communications accidents caused by reaching a third party using the same IP address).