[CUWiN-Dev] Re: intro & network mapping

[David Young]

On Sun, Feb 26, 2006 at 02:03:35PM -0600, T wrote:
> > Hi Tom, and welcome.  I am glad you are having fun exploring the network.
> > Let me tell you a couple of tricks.
> >
> > You can examine the IPv4 routing table like this:
> >
> > % netstat -rn -f inet
> 
> 
> I'm assuming you mean "netstat -r -f inet"...

-n suppresses the name lookups.  Sometimes that is a lot faster.

> So one question is how often does hslsd update the routing table? Quite a
> few nodes are listed by netstat which I haven't been able to reach in any
> way.

hslsd will usually update the routing table within a few seconds of a
linkstate change, updating more quickly for changes to nearby links than
distant links.

It will be difficult for you to reach nodes that are more than three or
four hops away.

> You can find a bit more information in /var/db/linkstates.  The routing
> > daemon, hslsd, periodically writes all known linkstates (the condition
> > of router->router links) to that file.
> 
> Awesome, there's plenty for me to pore through here. Two questions that come
> up right off the bat though are given a line like the following:
> 
> 4-ref foreign router lsa interface 10.0.237.100 type ptmp masklen 32 index 1
> neighbor 10.0.186.29 seqno 2216760 flags 0x1<UP> metrics [(etx, 386)]
> 
> Is the number after etx the calculated distance/signal strength metric?

It's neither a distance nor a signal strength.  ETX is a rough measure
of how many times a packet has to be transmitted before it reaches the
destination, including retransmissions.

> My
> other question is if the "neighbor 10.0.186.29" part means that the two
> nodes are "directly" connected (i.e. no hops between the two)?

Yes.

Dave

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-- 
David Young             OJC Technologies
dyoung at ojctech.com      Urbana, IL * (217) 278-3933