Current version compared with version Mon Sep 20 06:52:57 GMT 2004...
It works using an [IP] header bit called the `Don't fragment` bit. Usually when a gateway forwards a packet from a network to another with
- an [MTU] value that's smaller than the packet size, the packet gets fragmented in littlest parts. Instead if the `Don't fragment` bit is set in the [IP] header, the gateway
+ an [MTU] value that's smaller than the packet size, the packet gets fragmented in smaller parts (called fragments).
+ Instead if the `Don't fragment` bit is set in the [IP] header, the gateway
will refuse to fragment the packet, and will instead send an [ICMP] error of type `Fragmentation required but Don't fragment big set` to the source of
the packet. The error will quote part of the original packet, so the source has a way to know that it must use packets with a minor length when sending
to a given destination. The sender will try with smaller packets, if still an ICMP error will return, it will try again with a smaller packet and so on,
- until the outgoing packets will be smaller enough to ensure no fragmentation will occur.+ until the outgoing packets will be smaller enough to ensure no fragmentation will occur.
+
+
+ Other sources of information:
+
+ [link http://www.faqs.org/rfcs/rfc1191.html RFC1191]
+
+ [link http://www.netheaven.com/pmtu.html]
+
+
+ See Also:
+
+ [Path MTU], [MTU], [Path MTU spoofing] The following is the old page content
|