Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!brutus.cs.uiuc.edu!north
From: zweig@brutus.cs.uiuc.edu (Johnny Zweig)
Newsgroups: comp.protocols.tcp-ip
Subject: Router/Gateway laziness question
Summary: Taking shortcuts inside a router/gateway might win
Keywords: gateway router
Message-ID: <1989Sep8.190943.9450@brutus.cs.uiuc.edu>
Date: 8 Sep 89 19:09:43 GMT
Sender: news@brutus.cs.uiuc.edu
Distribution: comp
Organization: U of Illinois, CS Dept., Systems Research Group
Lines: 16

I was just thinking about what would happen if I had a relatively slow
controller routing packets between two nets with lots of excess bandwidth, and
decided to punt a few things. For example, how about if the router just
checked the checksum, looked at the destination IP-address, and forwarded the
packet out the appropriate interface without checking that the options are all
acceptable, etc., etc. Basically, I would trade the possibility of wasting
bandwidth on brain-damaged packets and other garbage off against wasting
controller cycles checking things over and over again.

Would this violate any extant or soon-to-be-released conformance criteria
(i.e. RFCs, or other documents)? It seems dumb to check the correctness of the
packets over and over again if it has to go through several hops on not-too-
loaded nets, but I know RFC792 (etc.) often say "if <such-and-such is
messed up> the packet MUST be dropped".

-Johnny Speculative