[Lvlug] One Machine on Network can't see TCP/IP 192.168.0.1 (or .sometimes .2)

[Randy Kramer]

Faber Fedor wrote:
> On Mon, Dec 17, 2001 at 03:08:53PM -0500, Randy Kramer wrote:
> > >From my old Linux server, I see the ping request (like "... icmp: echo
> > request"), then an "... arp who-has" and an "arp reply",
> 
> Okay, I take that to mean the NIC saw the arp request and responded, but
> the ICMP message never got up (or back down) the OSI stack.  Are you
> using the proper drivers for the NIC?

Yeah, I'm quite certain at both ends -- .2 has been my mail server for
years, replaced the NIC about a year ago with an identical spare.  (Next
one I lose I've got a problem -- need to find one with an ISA bus and a
"packet driver" (IIRC).) 

.5 (my new machine) recognized the card in Linux and Windows, and
installed a driver with the correct model number.  And, it can ping and
be pinged by all the other machines except .2.

> 
> > but I don't see
> > the "...icmp: echo reply" (which I do see for pings to other machines).
> >
> > So, the ping request is getting out on the network (I assumed it
> > wasn't), but 192.168.0.2 is not seeing it (or I am not seeing the
> > response).  I guess I need to put a sniffer closer to 192.168.0.2 -- now
> > it would be nice to have Linux on my laptop.
> 
> Closer?  Why?  Signal degradation?

Hmm, OK, at first I wasn't sure that the arp reply was coming from the
destination NIC (.2), but I guess that makes the most sense.  On the
assumption that the arp reply was coming from some other machine (is
that possible), I wanted to get closer (signal degradation) and see
whether the icmp:echo reply was visible closer to .2 (meaning that it
was receiving the request, generating a response, but it wasn't getting
anywhere), or whether the icmp: echo request was perhaps not visible
closer to .2, meaning .2 never got the request.

I now have linux up on .1, which is closer to .2, and I'll be back in a
few minutes with what I find.

I'm back -- I'm not sure that helps me.  .1 sees the icmp: echo request
(and the arp stuff), but no echo reply.  Interesting.  Also, .1 can't
ping .2, and, as it happens, .1 and .5 are both the same kind of
computers (motherboard).  They do have different NICs.  Aside from .5
and .1 not being able to ping .2, everybody else can ping everybody else
(except that I don't have a ping program in .10 to try pinging from it).

Could there be something so different about those two computers that
they can't ping .2??  Yet they can ping anybody else, including each
other??  Wierd!!

Anyway, I'll probably just let things as they are for now.

thanks,
Randy Kramer


> 
> --
> 
> Regards,
> 
> Faber
> 
> Linux New Jersey: Open Source Solutions for New Jersey
> http://www.linuxnj.com
> 
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