LAN activity light on router

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I have noticed that the LAN lights on either of my Linksys routers will
normally go off when that particular machine is shutdown, as expected.
 From the docs, the light is supposed to indicate when the router is
"successfully connected" to the machine. I have one machine for which
the LAN light stays on when the machine is shut down, and will only go
out when the machine is actually unplugged from power. What's up with
that? Does "successfully connected" mean just the cabling or does it
mean a powered ethernet adaptor?

Re: LAN activity light on router



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Welcome to "Wake on LAN".  That's where your the power to the ethernet
card or port in your computah remains powered and active even when the
computah is turned off.  The idea is that some server sends your
workstation a "magic packet" that turns on the computer, performs some
type of maintenance ritual, and then shuts the computah off.  It's
kinda nifty technology.



--
Jeff Liebermann    jeffl@comix.santa-cruz.ca.us
150 Felker St #D   http://www.LearnByDestroying.com
Santa Cruz CA 95060    AE6KS  831-336-2558

Re: LAN activity light on router


Jeff Liebermann wrote:
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One of the annoying things about a PC we have is that there is no set up
for this in the bios and I only found out because of the inbuilt cards
Led's remaining lit.It unfortunately doesn't work for a complete power
down,in this machines case, but from "Standby".So if I am feeling lazy,I
run a DC program which is disabled at midnight, I let the machine go
into standby and the following morning I can use a wifi equipped Laptop
to restart the PC .Like a lot of things, something to play with.
I use this on the laptop:-
http://www.amd.com/us-en/assets/content_type/utilities/magic_pkt.exe
A handy little extra if you like to play with VNC or such like.

Re: LAN activity light on router


Jeff Liebermann wrote:
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OK, I have heard of Wake on LAN. Sounds useful when you want it, but
annoying when you don't. When I installed one network card there was a
short jumper cable which I believe was for Wake on LAN support.
I am guessing this feature is only possible if the motherboard and PS
are designed to support it, or another method (jumper) is installed to
bring power to the card.

Thing is, both PCs I am looking at have Wake on Lan capabilities.
Machine A (newer, integrated ethernet) had Wake on LAN enabled as a
default, yet the router light was never on when the machine was not
running. I have occasionally found this machine mysteriously running
when I know all my machines were shut down. I have since diabled Wake on
LAN on this machine. Should I assume that someone sent a magic packet as
part of a scan?

Machine B (older, SMC EZ PCI card) has never had Wake on LAN enabled,
yet the router light is on when it is not running. There must be a
difference in the design of the different network cards between machines
A and B which allows both to support Wakeup, but different behaviors
with the router lights. I'd rather the light was out. How do the latest
add-in cards behave?



Re: LAN activity light on router



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Yep.  3 wires from the card to the motherboard.

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Yep.  The power comes through the 3 wires.  Pull the cable and there's
no power on the ethernet card.  Most motherboards with ethernet chips
have a jumper or bios setting to enable or disable the WOL feature.

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No.  WOL uses broadcasts.  Broadcasts do not usually propogate through
firewalls and NAT routers.  If your home LAN was directly connected to
the internet through a dialup modem, cable modem, satellite modem, or
DSL modem, then it's possible that a broadcast came in from the
internet and turned on the computah.  However, if you have an NAT
router in between, the broadcast will not go through to your
workstation.  You can setup your router for a DMZ to your workstation
and everything will go through to it.  Some routers and VPN's can also
be configured to pass broadcasts.  However, the perpetrator will need
to know the MAC address of your workstation.  That's easy if you're
directly connected to the internet (no router).  However, if there's
an NAT router in the way, everything on the WAN side shows the routers
MAC address, and not your computahs MAC address.  Therefore, I suggest
that it's highly unlikely that someone either accidentally or
intentionally turned on your PC from the internet.

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There's a light on the motherboard that's usually on when the computah
is turned off, but without the cable or jumper installed, there's no
power to the ethernet card, so the network lights should be off.  I
have a Dell Inspiron 4600, with an Intel Pro100+ adapter, that has WOL
enabled.  Power is off, ethernet lights are on.  Lights on the
ethernet switch are on.  It has to be that way or the link is disabled
and no "magic packets" get through.  Yank the WOL cable, and all the
lights except the one on the motherboard go out.

I don't see the problem with the lights being on.


--
Jeff Liebermann    jeffl@comix.santa-cruz.ca.us
150 Felker St #D   http://www.LearnByDestroying.com
Santa Cruz CA 95060    AE6KS  831-336-2558

Re: LAN activity light on router


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The WOL "flying lead" cable is NOT installed, and there are no other
jumpers on the card. All the APM and adaptor settings have WOL type
behavior disabled. No BIOS option exists for WOL on this machine.
The only possiblity I see is the card is powered from the VAUX pin on
the PCI bus as described here:

http://www.planetanalog.com/printableArticle.jhtml?articleID=12801381

It would seem that I just can't get what I'm after.

As to the why, I'd just like the lights on the switch to actually mean
something useful and consistent. The most useful meaning to me is that
the PC is up and running. It is a simple check to glance at the switch
and know that machines or devices that are supposed to be off are off
(desktops maybe), and machines or devices that are supposed to be on are
on (servers, dataloggers, home control...). My network is simple now,
but I plan to add more.

Going a bit further, how about a method/device which would also tell me
at a glance (I am thinking LEDs again) the active state of ALL network
connected devices, wired or wireless? Can I get the info from my gateway
router's tables or do I need an IDS box/firewall? A big switch would
kind of do this, except where additional routers or bridges are letting
many clients share the same wire. Could a WRT54G be adapted to do this?








Re: LAN activity light on router



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My motherboard is comparatively ancient.  I don't wanna open the case
again to get the make and model.  When I yanked on the WOL cable, the
lights went out.  I guess you're a victim of progress.

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I think that was the chorus of a song.  "You can't always get what you
want.  But if you try real hard, my might get what you need".

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Well, ok.  However, I don't see that as a requirement for proper
operation.  I use the lights quite a bit for diagnostics and have
learned to live with seeing lights on when the computah is off.  When
I'm in the server room, and staring at a wall full for switches,
there's no way for me to tell if anything is alive and well.  Yeah,
it's inconvenient, but not fatal.

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Easy.  I do it all the time.  It's called SNMP or Simple Network
Management Protocol.  The latest free release of Sveasoft Alchemy for
the WRT54G supports SNMP.  I've been playing with it a bit and it
seems to work.  It will disclose all kinds of connection, status, and
traffic information.  I'm still putting together a MIB database
collection for the WRT54G, so I'm not sure exactly what's in there,
but so far, it looks useful.

There are quite a few SNMP tools that can be used to extract the
information:
  http://www.snmplink.org
  http://www.net-snmp.org

MRTG for traffic graphs:
  http://people.ee.ethz.ch/~oetiker/webtools/mrtg /

MIB browser (GetIf)
  http://www.wtcs.org/snmp4tpc/getif.htm

If you just want status info for connections, there are programs, such
as Big Brother, that will show if a device is up or down by simply
pinging it, or trying to download a web page.  If you know the
device's MAC address, you can obtain the IP address via ARP (address
resolution protocol) or just dig it out of the routers SNMP tables,
ping the device, and display the return status.  If you want to do a
first class job of this (on Linux), try Nagios:
  http://www.nagios.org
I used this (actually NetSaint.org) years ago to get status info on a
mess of Breezecom SA10 radios, which would page me if any of the links
went down for more than 10 minutes.

Anyway, SNMP sure beats looking at flashing lights.  Good luck.

--
Jeff Liebermann    jeffl@comix.santa-cruz.ca.us
150 Felker St #D   http://www.LearnByDestroying.com
Santa Cruz CA 95060    AE6KS  831-336-2558


Re: LAN activity light on router


tns1 wrote:
8><..........................................
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Depends on your NIC ,newer ones have WOL through their PCI connection.
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No ,a "refresh of the network state" can cause this.
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If you are using XP and wish to disable it go to "network connections"
rt click on the ethernet connection and choose properties ,choose
"configure" and pick the "Power Management" tab,uncheck the box "Allow
this device to bring the computer out of standby".When you next power
down the NIC Led's should not be lit.


Re: LAN activity light on router


NBT wrote:
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Already set that way.

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