The URL you want is:
It makes for kinda dry reading though (all 362 pages of it).
Eh? I haven't snarfed std5.txt recently, but I just checked rfc791,
and it's only 45 pages. I don't know what std5 is, but it ain't
just rfc791 (which is the original IP spec), judging from the length.
If you have the cash I'd recommend getting Sidnie Feit's "TCP/IP"
and/or W. Richard Stevens' "TCP/IP Illustrated Vol. 1" books instead
Strong second. Another possibility is Volume 1 of Comer's Internet books.