[gentoo-user] Port Tracer Program Needed

[gentoo-user] Port Tracer Program Needed

[Timothy A. Holmes]

Hi Folks:

I am getting ready to start a project here in the building to map the
physical infrastructure of our network (its been assembled kinda willy
nilly over the last 8 years or so).  I am looking for a program to run
on my laptop that I can plug into a wall plate and it will cause the
port activity lights on the switch to blink distinctly so that I can
begin tracing plugs to ports.  Due to budgetary constraints, open source
/ freeware is very very preferable.

Thanks


Timothy A. Holmes
IT Manager / Network Admin / Web Master / Computer Teacher
 
Medina Christian Academy
A Higher Standard...
 
Jeremiah 33:3
Jeremiah 29:11
Esther 4:14



-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] Port Tracer Program Needed

[Hans-Werner Hilse]

Hi,

On Tue, 14 Mar 2006 10:03:24 -0500 "Timothy A. Holmes"
<tholmes@mcaschool.net> wrote:

> I am getting ready to start a project here in the building to map the
> physical infrastructure of our network (its been assembled kinda willy
> nilly over the last 8 years or so).  I am looking for a program to run
> on my laptop that I can plug into a wall plate and it will cause the
> port activity lights on the switch to blink distinctly so that I can
> begin tracing plugs to ports.  Due to budgetary constraints, open
> source / freeware is very very preferable.

Not sure about "distinctly" (that will certainly depend on the switch's
electronic and programmatic design), but - tada - you can usually cause
the traffic light on the switch to blink with network traffic ;-)

So broadcasting some UDP packages out into the wild should be
sufficient. Use e.g. netcat. OTOH, you might want to play with ethtool
and switch connection rates for short intervals. Usually switches have
a light indicator for the speed, too, so that should be easier to
distinct on a busy switch. Toggle this in a shell loop with a few
"sleep"s inserted...

-hwh
-- 
gentoo-user@gentoo.org mailing list

RE: [gentoo-user] Port Tracer Program Needed

[Timothy A. Holmes]

Hans -- Thank you,  I realize that I can make it blink with network
traffic, the problem is that basically all the ports on the switches
have traffic running constantly on them, so I need to find a way to make
it distinctive enough so it can be picked out from the rest of the
noise.

I will try to run down the tools that you mentioned and see if any of
them provide a solution -- thank you

TIM


Timothy A. Holmes
IT Manager / Network Admin / Web Master / Computer Teacher
 
Medina Christian Academy
A Higher Standard...
 
Jeremiah 33:3
Jeremiah 29:11
Esther 4:14

> -----Original Message-----
> From: Hans-Werner Hilse [mailto:hilse@web.de]
> Sent: Tuesday, March 14, 2006 12:01 PM
> To: gentoo-user@lists.gentoo.org
> Subject: Re: [gentoo-user] Port Tracer Program Needed
> 
> Hi,
> 
> On Tue, 14 Mar 2006 10:03:24 -0500 "Timothy A. Holmes"
> <tholmes@mcaschool.net> wrote:
> 
> > I am getting ready to start a project here in the building to map
the
> > physical infrastructure of our network (its been assembled kinda
willy
> > nilly over the last 8 years or so).  I am looking for a program to
run
> > on my laptop that I can plug into a wall plate and it will cause the
> > port activity lights on the switch to blink distinctly so that I can
> > begin tracing plugs to ports.  Due to budgetary constraints, open
> > source / freeware is very very preferable.
> 
> Not sure about "distinctly" (that will certainly depend on the
switch's
> electronic and programmatic design), but - tada - you can usually
cause
> the traffic light on the switch to blink with network traffic ;-)
> 
> So broadcasting some UDP packages out into the wild should be
> sufficient. Use e.g. netcat. OTOH, you might want to play with ethtool
> and switch connection rates for short intervals. Usually switches have
> a light indicator for the speed, too, so that should be easier to
> distinct on a busy switch. Toggle this in a shell loop with a few
> "sleep"s inserted...
> 
> -hwh
> --
> gentoo-user@gentoo.org mailing list



-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] Port Tracer Program Needed

[Heiko Wundram]

Am Dienstag, 14. März 2006 18:08 schrieb Timothy A. Holmes:
> Hans -- Thank you,  I realize that I can make it blink with network
> traffic, the problem is that basically all the ports on the switches
> have traffic running constantly on them, so I need to find a way to make
> it distinctive enough so it can be picked out from the rest of the
> noise.

Save the following script as floodping.sh, and try it, you should be able to 
notice the traffic from your regular traffic:

#!/bin/sh
ifconfig $1 10.0.0.1 netmask 255.255.255.0 broadcast 10.0.0.255
while true
do
	ping -f -w $2 -b 10.0.0.255
	sleep $2
done

./floodping.sh eth0 5

would mean that it does five seconds of intensive traffic (which has packets 
going to the switch in the order of <20ms or so, depending on your laptop, 
and the lamp should blink very frequently), then does five seconds of data 
sleep, which should be almost completely quiet on the switch (except for that 
occasional broadcast packet from another computer directed at yours).

Be sure to use a network that isn't on your local net for testing, as my 
network is 192.*, I've used 10.* in the example. If you use a network that's 
regularily used on your network, you might get problems discerning the sleep 
phase, as the arp address of your laptop propagates to all other endpoints on 
your net due to the use of a regular network, and this might mean a lot of 
ARP queries, depending on your network size.

I've used a technique like this to check the cabling in a building, and it 
worked just fine.

HTH!

-- 
--- Heiko.

-- 
gentoo-user@gentoo.org mailing list

RE: [gentoo-user] Port Tracer Program Needed

[Timothy A. Holmes]

WOW -- that looks great -- Thank you very very much

I will be trying it shortly

TIM

Timothy A. Holmes
IT Manager / Network Admin / Web Master / Computer Teacher
 
Medina Christian Academy
A Higher Standard...
 
Jeremiah 33:3
Jeremiah 29:11
Esther 4:14

> -----Original Message-----
> From: Heiko Wundram [mailto:me+gentoo-user@modelnine.org]
> Sent: Tuesday, March 14, 2006 12:50 PM
> To: gentoo-user@lists.gentoo.org
> Subject: Re: [gentoo-user] Port Tracer Program Needed
> 
> Am Dienstag, 14. März 2006 18:08 schrieb Timothy A. Holmes:
> > Hans -- Thank you,  I realize that I can make it blink with network
> > traffic, the problem is that basically all the ports on the switches
> > have traffic running constantly on them, so I need to find a way to make
> > it distinctive enough so it can be picked out from the rest of the
> > noise.
> 
> Save the following script as floodping.sh, and try it, you should be able
> to
> notice the traffic from your regular traffic:
> 
> #!/bin/sh
> ifconfig $1 10.0.0.1 netmask 255.255.255.0 broadcast 10.0.0.255
> while true
> do
> 	ping -f -w $2 -b 10.0.0.255
> 	sleep $2
> done
> 
> ./floodping.sh eth0 5
> 
> would mean that it does five seconds of intensive traffic (which has
> packets
> going to the switch in the order of <20ms or so, depending on your laptop,
> and the lamp should blink very frequently), then does five seconds of data
> sleep, which should be almost completely quiet on the switch (except for
> that
> occasional broadcast packet from another computer directed at yours).
> 
> Be sure to use a network that isn't on your local net for testing, as my
> network is 192.*, I've used 10.* in the example. If you use a network
> that's
> regularily used on your network, you might get problems discerning the
> sleep
> phase, as the arp address of your laptop propagates to all other endpoints
> on
> your net due to the use of a regular network, and this might mean a lot of
> ARP queries, depending on your network size.
> 
> I've used a technique like this to check the cabling in a building, and it
> worked just fine.
> 
> HTH!
> 
> --
> --- Heiko.
> 
> --
> gentoo-user@gentoo.org mailing list



-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] Port Tracer Program Needed

[Heiko Wundram]

Am Dienstag, 14. März 2006 19:24 schrieben Sie:
> I created the script as you suggested, and when I executed it ALL the
> lights on the ports that have connections go nuts

Okay, your switches are layer 2 switches, not layer 3 switches then... (they 
don't understand IP traffic, only ethernet traffic; a broadcast ping is a 
broadcast ethernet packet which gets forwarded to every port by a layer 2 
switch). I didn't think of that when I sent out the snippet; our switches are 
layer 3 switches, and they won't forward packets between different network 
segments, even when they are in the same ethernet segment.

But, you can still make this work if you have two computers connected to the 
network, one which you know the switch port and IP of.

Your setup should look something like this:

------------------------------------
|     Switch                       |
--|------------------------------|--
  Port 1 (192.168.0.1)           Port x (your Laptop, fixed at 192.168.123.45,
                                         some address not on your network)

Port 1 mustn't necessarily be port 1, may also be any other port, just as you 
may use any other IP you know.

Then, try the following:

#!/bin/sh
# Set up networking, adjust to fit your network.
ifconfig $1 192.168.123.45 netmask 255.255.0.0 broadcast 192.168.255.255

# Standard loop.
while true
do
	ping -f -w $2 192.168.0.1 # Your known host IP
	sleep $2
done

When you call this script (just as before), only those two ports which are 
present in the diagram above should start to fire (and sleep), and as you 
know one of them, the other can't be hard to actually discern from the rest 
of the ports on the switch.

If the above doesn't work, there are other ways which involve creating 
ethernet packets with invalid recipient address at high speeds which 
shouldn't get forwarded by a layer 2 switch, but these involve a little more 
trickery than a small shell script. I'd be happy to write a little 
Python-Program which does just this, but before I do, test the above. ;-)

-- 
--- Heiko.

-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] Port Tracer Program Needed

[Justin Krejci]

On Tuesday 14 March 2006 11:08 am, Timothy A. Holmes wrote:
> Hans -- Thank you,  I realize that I can make it blink with network
> traffic, the problem is that basically all the ports on the switches
> have traffic running constantly on them, so I need to find a way to make
> it distinctive enough so it can be picked out from the rest of the
> noise.
>
> I will try to run down the tools that you mentioned and see if any of
> them provide a solution -- thank you
>
> TIM
>
>
> Timothy A. Holmes
> IT Manager / Network Admin / Web Master / Computer Teacher
>
> Medina Christian Academy
> A Higher Standard...
>
> Jeremiah 33:3
> Jeremiah 29:11
> Esther 4:14
>
> > -----Original Message-----
> > From: Hans-Werner Hilse [mailto:hilse@web.de]
> > Sent: Tuesday, March 14, 2006 12:01 PM
> > To: gentoo-user@lists.gentoo.org
> > Subject: Re: [gentoo-user] Port Tracer Program Needed
> >
> > Hi,
> >
> > On Tue, 14 Mar 2006 10:03:24 -0500 "Timothy A. Holmes"
> >
> > <tholmes@mcaschool.net> wrote:
> > > I am getting ready to start a project here in the building to map
>
> the
>
> > > physical infrastructure of our network (its been assembled kinda
>
> willy
>
> > > nilly over the last 8 years or so).  I am looking for a program to
>
> run
>
> > > on my laptop that I can plug into a wall plate and it will cause the
> > > port activity lights on the switch to blink distinctly so that I can
> > > begin tracing plugs to ports.  Due to budgetary constraints, open
> > > source / freeware is very very preferable.
> >
> > Not sure about "distinctly" (that will certainly depend on the
>
> switch's
>
> > electronic and programmatic design), but - tada - you can usually
>
> cause
>
> > the traffic light on the switch to blink with network traffic ;-)
> >
> > So broadcasting some UDP packages out into the wild should be
> > sufficient. Use e.g. netcat. OTOH, you might want to play with ethtool
> > and switch connection rates for short intervals. Usually switches have
> > a light indicator for the speed, too, so that should be easier to
> > distinct on a busy switch. Toggle this in a shell loop with a few
> > "sleep"s inserted...
> >
> > -hwh
> > --

Netwox (+ optionally netwag) has some neat tools. One that I have found handy 
is the audible ping. Whenever it receives a successful ping response it beeps 
your pc speaker. It may or may not have any benefit for you in this secenario 
but it can be useful at times when you are muddling around and can't see your 
screen, you can just listen for the "beep, beep, beep" then disconnect the 
proper cable and it goes silent. Or in the reverse, plug in the right cable 
and you start to hear the "beep, beep, beep". 

Netwox has a ton of other neat tools, servers and clients.

If your switches are manageable you can probably look up your switches cam 
table (MAC address to eth port mapping) then look at your clients ARP cache 
after pinging your broadcast address on each network.

Good luck on your network mapping.
-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] Port Tracer Program Needed

[Justin Krejci]

On Tuesday 14 March 2006 11:08 am, Timothy A. Holmes wrote:
> Hans -- Thank you,  I realize that I can make it blink with network
> traffic, the problem is that basically all the ports on the switches
> have traffic running constantly on them, so I need to find a way to make
> it distinctive enough so it can be picked out from the rest of the
> noise.
>
> I will try to run down the tools that you mentioned and see if any of
> them provide a solution -- thank you
>
> TIM
>
>
> Timothy A. Holmes
> IT Manager / Network Admin / Web Master / Computer Teacher
>
> Medina Christian Academy
> A Higher Standard...
>
> Jeremiah 33:3
> Jeremiah 29:11
> Esther 4:14
>
> > -----Original Message-----
> > From: Hans-Werner Hilse [mailto:hilse@web.de]
> > Sent: Tuesday, March 14, 2006 12:01 PM
> > To: gentoo-user@lists.gentoo.org
> > Subject: Re: [gentoo-user] Port Tracer Program Needed
> >
> > Hi,
> >
> > On Tue, 14 Mar 2006 10:03:24 -0500 "Timothy A. Holmes"
> >
> > <tholmes@mcaschool.net> wrote:
> > > I am getting ready to start a project here in the building to map
>
> the
>
> > > physical infrastructure of our network (its been assembled kinda
>
> willy
>
> > > nilly over the last 8 years or so).  I am looking for a program to
>
> run
>
> > > on my laptop that I can plug into a wall plate and it will cause the
> > > port activity lights on the switch to blink distinctly so that I can
> > > begin tracing plugs to ports.  Due to budgetary constraints, open
> > > source / freeware is very very preferable.
> >
> > Not sure about "distinctly" (that will certainly depend on the
>
> switch's
>
> > electronic and programmatic design), but - tada - you can usually
>
> cause
>
> > the traffic light on the switch to blink with network traffic ;-)
> >
> > So broadcasting some UDP packages out into the wild should be
> > sufficient. Use e.g. netcat. OTOH, you might want to play with ethtool
> > and switch connection rates for short intervals. Usually switches have
> > a light indicator for the speed, too, so that should be easier to
> > distinct on a busy switch. Toggle this in a shell loop with a few
> > "sleep"s inserted...
> >
> > -hwh
> > --

Netwox (+ optionally netwag) has some neat tools. One that I have found handy 
is the audible ping. Whenever it receives a successful ping response it beeps 
your pc speaker. It may or may not have any benefit for you in this secenario 
but it can be useful at times when you are muddling around and can't see your 
screen, you can just listen for the "beep, beep, beep" then disconnect the 
proper cable and it goes silent. Or in the reverse, plug in the right cable 
and you start to hear the "beep, beep, beep". 

Netwox has a ton of other neat tools, servers and clients.

If your switches are manageable you can probably look up your switches cam 
table (MAC address to eth port mapping) then look at your clients ARP cache 
after pinging your broadcast address on each network.

Good luck on your network mapping.
-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] Port Tracer Program Needed

[Dave Moore]

> Netwox (+ optionally netwag) has some neat tools. One that I have found handy
> is the audible ping. Whenever it receives a successful ping response it beeps
> your pc speaker. It may or may not have any benefit for you in this secenario
> but it can be useful at times when you are muddling around and can't see your
> screen, you can just listen for the "beep, beep, beep" then disconnect the
> proper cable and it goes silent. Or in the reverse, plug in the right cable
> and you start to hear the "beep, beep, beep".

You can do that with ping -a too :D

Dave

--
-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GAT d-(+) s+: a24 C++ UBL++ P+>+++ L++ E--- W+++$ N+ o? K? w O? M-- V?
!PS !PE Y PGP- t++ 5++ X+ R+++ tv+ b++ DI++++ D++ G e+ h-- r++ y+
------END GEEK CODE BLOCK------

-- 
gentoo-user@gentoo.org mailing list