Deja Vu all over again

ME dugan at
Sun Apr 1 11:11:30 PDT 2001

On Sun, 1 Apr 2001, John F. Kohler wrote:
> The new (Jameco) card is back in place, and re-seating it may have been
> fortunate.  I have 4 terminal windows up on the GNOME desktop, all pinging the respective
> router ports.
> (router)
> (Mac LC)
> iMac)
> (Linux box)
> typical range of ping response for the router is 700-800 usec
> typical range of ping response for the LC is 1.6 to 1.7 msec
> typical range of ping response for the iMac is 700-800 usec
> typical range of ping respons for the linus is 48-70 usec

Well, then let's assume that they are reachable. Next, try to ping
something outside your network:

# ping -c 50
Let it run for a bit, if that returns positive results then let's

# nslookup

Does the nslookup return something like:

Server:  ns1?


Is the above reported?

If so, then let us continue...

Since you say you have GNOME up an running, try launching netscape. See if
you are able to browse the web. If not, then we can try other things.

> I do, in fact have a mac utility on my LC desktop "Mac TCP watcher, "
> which allows me to do several tasks including to ping the rest of the network,
> as well as URLs in the outside world.  I have seen the "traceroute" feature,
> but seldom used it.  I don't know the purpose of it.

Go ahead and use this to ping your linux box. I suspect it will work, but
it would be good to verify it anyway.

"traceroute" is a tool to tell you how many router hops exist between you
and another point on the internet - assuming all your packets take that
route. (There is no guarantee that all of your traffic will necessarily
follow that path all of the tme, but it is likely it will travel that
route most of the time.)

Here is an example of traceroute:
dugan at nerds:~$ /usr/sbin/traceroute
traceroute to (, 30 hops max, 38 byte
 1 (  1.436 ms  0.862 ms  0.823 ms
 2 (  20.538 ms  24.879 ms
16.212 ms
 3 (  18.108 ms  16.810 ms  16.041 ms

In the above, my machine's packets must pass through my router
"" and the number that follow are a measure of
latency. By doing three tests it helps you to get an average. Then my
router hands off the packet to another router
" who then gets the packet to where it needs
to go at

The above is a fairly short traceroute path. When I perform one to an SSU
server, I pass about 15 hops as routers diirect the packets on their way,
getting closer to the destination.

traceroute can be useful to find out if a link between you and anoter
location is down, or troubeshoot "loops" in routing policies.

Check out the manpage for traceroute on your linux box for a more detailed


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