[comp.protocols.tcp-ip] SLIP strangeness

man@edsdrd.eds.com (Marc Nurmi) (08/14/90)

I've set up a dialup SLIP connection between two Suns running
4.1 SunOS, and it has been working fine.  I have noticed, however,
that the Sun that I'm dialed into is sending a bunch of packets 
(45, to be exact) over the SLIP link every 30 seconds.  At first, 
I thought this was routing information generated by gated (which is 
running at both ends), but these packets are still generated, even 
if gated is brought down.

Does anyone know what this information is, and what might be 
generating it???

Also, is there a tool like etherfind available for serial IP links?
"netstat" gives me packet counts for information flowing across the
SLIP link, but I was wondering if there was some way to look at
this information.

Oh, by the way, I'm not sure if it matters or not, but I'm running
the SLIP compression routines (CSLIP), and am using a pair of
Telebit T2500 modems in PEP mode.  My main concern here is that
these unexplained packets appear to be effecting the throughput
of the SLIP link.  Any assistance is greatly appreciated!

-- 
Marc Nurmi - man@edsdrd.eds.com
... uunet!edsr!edsdrd!man

jc@minya.UUCP (John Chambers) (08/21/90)

> Oh, by the way, I'm not sure if it matters or not, but I'm running
> the SLIP compression routines (CSLIP), and ...

Hmmm... The folks around where I'm working have been discussing adding
a compression feature to SLIP, and a bit of investigation turned up no
evidence that anyone had done it.  This passage makes it sound like it
has been done.  Does anyone know details?  Is the source available for
copying or purchasing (under or over the table ;-)?

I've been thinking of subroutinizing the heart of compress as a way of
getting the job done, though with the latest fuss over the legality of
using compress, this may not be an option.  Of course, I could always
hack up a compress routine of my own; even a dumb one would have to 
give a measurable improvement over all the null and repeated bytes in
the typical IP header.  But getting it already done would be so much
faster, y'know.

-- 
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