Difference between revisions of "Broadcast"
m |
|||
| Line 1: | Line 1: | ||
A broadcast is likened to radio and is by definition one sender and multiple receivers. [[Ethernet]] can broadcast, [[IP]] can broadcast. | A broadcast is likened to radio and is by definition one sender and multiple receivers. [[Ethernet]] can broadcast, [[IP]] can broadcast. | ||
| + | Broadcasting is stateless, meaning you cannot use [[TCP]] with it. Most broadcasts are done with [[datagram|datagrams]]. | ||
=== Exploitation of Broadcasts === | === Exploitation of Broadcasts === | ||
In the Internet broadcasts are also possible but they are restricted to a specific site. At one point this wasn't so and an exploit called smurf became annoying especially for IRC networks. Smurf exploited the fact that one could spoof the source address of an ICMP echo packet destined for the broadcast address of a large network. All the computers on that network would reply with ICMP echo reply packets to the spoofed source which then becomes a victim to [[DoS]]. Smurf is also properly called an amplified broadcast attack. Router manufacturers soon disabled the option that a router should direct broadcasts inside a LAN from the Internet, this was done so because it would have been a lot harder to convince ISP's to filter spoofed source packets from their network (egress filtering). | In the Internet broadcasts are also possible but they are restricted to a specific site. At one point this wasn't so and an exploit called smurf became annoying especially for IRC networks. Smurf exploited the fact that one could spoof the source address of an ICMP echo packet destined for the broadcast address of a large network. All the computers on that network would reply with ICMP echo reply packets to the spoofed source which then becomes a victim to [[DoS]]. Smurf is also properly called an amplified broadcast attack. Router manufacturers soon disabled the option that a router should direct broadcasts inside a LAN from the Internet, this was done so because it would have been a lot harder to convince ISP's to filter spoofed source packets from their network (egress filtering). | ||
Revision as of 05:41, 4 December 2005
A broadcast is likened to radio and is by definition one sender and multiple receivers. Ethernet can broadcast, IP can broadcast.
Broadcasting is stateless, meaning you cannot use TCP with it. Most broadcasts are done with datagrams.
Exploitation of Broadcasts
In the Internet broadcasts are also possible but they are restricted to a specific site. At one point this wasn't so and an exploit called smurf became annoying especially for IRC networks. Smurf exploited the fact that one could spoof the source address of an ICMP echo packet destined for the broadcast address of a large network. All the computers on that network would reply with ICMP echo reply packets to the spoofed source which then becomes a victim to DoS. Smurf is also properly called an amplified broadcast attack. Router manufacturers soon disabled the option that a router should direct broadcasts inside a LAN from the Internet, this was done so because it would have been a lot harder to convince ISP's to filter spoofed source packets from their network (egress filtering).
