Maximum sized IP packets


Bob Beach (ultra!bob@ames.arc.nasa.gov)
Wed, 20 Apr 88 17:28:40 PDT


In looking through the IP RFC, I noticed that IP allows up to a 64K byte
datagram. I was wondering how many implementations of TCP/IP are
actually capable of handling such a large datagram. Such a datagram would
have to fragmented since no subnets that I know of support packet sizes
that big, so I guess the real question is: what implementations can reassemble
a 64K IP datagram that has been previously fragmented.

A second question is: if the 64K datagram size is, in the words of the RFC
"impractical", what is "practical"? 4K, 8K? I have heard rumors that many
implementation don't support reassembly at all. Is this true?

A third question is: given some implementation can reassemble 128 (or so)
576 byte packets into one big 64K datagram, how likely is it that all
128 would arrive at the destination node. The destination could be either a
host on the Internet or on a local Ethernet.

-Bob Beach
 Ultra Network Technologies



This archive was generated by hypermail 2.0b3 on Thu Mar 09 2000 - 14:41:56 GMT