For the life of me I cannot figure out what is wrong with my second
computer on my network. I am using:

Comcast Cable internet
Linksys BEFSR41 Router with built in Switch
2 Computers both using Win2k on the network

I have my Comcast HSI on second floor going into linksys router. The
computer's connection at this location works fine.

My second computer located downstars is connected via a Gigafast
switch and a 25 ft CAT5 line running up through the ceiling into the
router.

Problem: The problem mostly arises with multiplayer gaming issues. 95%
of the time I cannot ping game server lists...in the case that I can,
the ping times will be extremely high. I regularly use All Seeing Eye
to ping game servers on my other computer and it works fine on that
one, but no go on the second.

I have replaced practically every part ( cat5 line, nic, switch, even
software drivers) and I can still not resolve this issue! I have even
tried using a different line over a completely different path in case
of interference issues, still nothing.

I figure it can't be my Linksys router because the other computer goes
through the router and works fine. Yes, I have tried different ports.

Anyone can solve this problem I will be greatly indebted to you!!

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Clarification of Question by shortywop-ga on 07 Apr 2004 13:56 PDT

I need the Gigafast switch because I occasionally connect other
computers to the network and I have my Xbox connected also.

The problem is not the switch, if I plug the line directly into my NIC
the same thing happens...I also tried a Dlink switch and had the same
problem.

Pinging computers on the network works fine, I get <10ms on both.

Tried static IP...still nothing. Aaarg!!

Is there not some kind of network packet testing program out there?

---

Clarification of Question by shortywop-ga on 07 Apr 2004 13:57 PDT

Also regarding the line issues...I have tried a total of 4 or 5
different CAT5 cables...and they are not the cheapos.

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Request for Question Clarification by poe-ga on 08 Apr 2004 02:17 PDT

Hi shortywop-ga,

I can appreciate how annoying this problem must be for. Let's see if
we can get it sorted for you.

As noted in the comments, you've tried many of the obvious things.
There is one, however, that is notably absent. You haven't
specifically mentioned the 'link speed and duplex' settings on your
NICs, so I presume you haven't looked at them.

Most NICs are set to 'Auto' as default, meaning that they will
auto-negotiate the speed at which they can connect to the network. I
would recommend changing this to the actual speed that they should
use.

For instance, if you are using a 100 MB NIC to connect your upstairs
machine to the Linksys router/switch, then you should set the NIC to
100 MB Full. You don't state the speed of the switch you are using
downstairs, but again, if this is a 100 MB NIC connecting to a 100 MB
switch, you should set it to 100 MB Full.

The setting can be found by clicking the Configure button that can be
found when looking at the properties of the NIC.

Please try this and let me know if it solves your problem, or whether
we need to look deeper.

poe-ga
Google Answers Researcher

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Clarification of Question by shortywop-ga on 08 Apr 2004 12:33 PDT

Upstairs computer: Asus motherboard, 512mb ram, Nforce2 onboard NIC, Win2k SP4
Downstairs computer: Epox motherboard, 512mb ram, Realtek RTL1839 NIC
(swapped out my D-link 530TX yesterday), Win2k SP4

Tried pinging servers from DOS prompt, I am getting high ping times there too.

Tried broken router, doesn't do anything, and I'm not using it on the upstairs ASE.

When I get server list for Jedi Knight 2 and Call of Duty, none of the
ping times for any of the servers are under 100ms and most are >
250ms.

I cannot even get a listing for Unreal Tournament 2004...it says it's
pinging the servers, progress bar finishes, then no listing comes up.

Now when using the in game server listing in Unreal, I do get some
servers to show up but it is only a fraction of what servers actually
exist, and all ping times show up as "?" or "N/A".

Cannot get a game server listing from inside Jedi Knight 2.

As far as a network testing program, I guess I am just looking for
something that will just diagnose your network and tell you what is
wrong, but I doubt anything like this exists.

Ah well if you have anything else I can try, please let me know.

---

Clarification of Question by shortywop-ga on 08 Apr 2004 23:34 PDT

Well I am now convinced 100% that this is a packet loss problem. Supporting facts:

Games:
-games unresponsive to certain keypresses, requiring me to press the key again
-fired bullets/ projectiles disappear or do not appear at all
-my character location will at times jump from one spot of a map to a
competely diffect area of the map
-pingtime and framerate will be above average so my problem could not
be attributed to lag or video card difficiency
-server listings are incomplete and only a fraction of an actual server list

Web development:
-Images uploaded are often corrupted and/or distorted and need to be re-uploaded

Web browsing:
-I often receive "Bad Requests" and have to go back and click a link again
-Images on pages often appear broken and require a page refresh to show up

If these are not enough to support this being a packet loss problem I
don't know what is.

I've also ordered 2 new Belkin cables...all other cables I have tried
were not name brand, so I'm trying Belkins as a last resort.

The Realtek is an RTL8139(A). Epox mb is an 8RDA. I tried pinging the
servers with ASE closed and there wasn't any noticeable ping
difference.

Let me know if you have any more advice or need anymore clarification.

---

Clarification of Question by shortywop-ga on 25 Apr 2004 21:22 PDT

Well I moved the computer upstairs where the router is and SAME THING!

So it's definitely not an interference issue now...

What's left? Replacing the router and then the motherboard? ARRRGH!!!!

One thing I forgot to mention...I had Windows XP home installed on
this computer and I reverted back to Win 2K...could that have possibly
done some damage? I ran system file checker and it turned out ok....

Shortywop,

This sounds like the old problem of the unnecessarily segmented LAN.
The BEFSR41 has a 4-port 10/100 switch built-in. The Gigafast switch
downstairs is entirely unnecessary, and it is either causing the
problem or preventing you from diagnosing it.

If you are using the Gigafast because you have other computers
downstairs that also need to be connected to the Linksys, then
disconnect them and connect the downstairs machine directly into the
BEFSR41. Then test ping to the gaming servers in that configuration:

Downstairs Machine ---- Linksys ---- Comcast HSI

Do this with the upstairs machine plugged in, then again with the
upstairs machine unplugged to see if there is any difference, and if
this has fixed it.

If you are using the Gigafast because of distance, then get a longer
cable to connect the downstairs machine directly to the BEFSR41. Try
and do this with a high quality cable. Cheap cables twist pairs by
colour pair. This is very wrong. In order reliably to go longer
distances with 100Base-T ethernet, you want a cable with the TX/RX
pairs twisted. You can tell by looking at the connector ends: cheap
cables will go something like orange-orange green-green blue-blue
brown-brown sequentially across the pins. Good cables will switch pins
4 & 6 to keep the TX/RX pairs properly twisted.

See http://www.nerdlabs.org/documents/tp_cable.php for the correct pinouts.

In fact, before you invest in a longer cable, try the configuration
with just the downstairs machine attached directly to the BEFSR41.
Move the computer closer if you have to. If that doesn't solve the
problem, then you know the problem is either the cable, the ethernet
card or the drivers in the downstairs machine. (You already know it
can't be the BEFSR41 because you have tried different ports, right?
And you have tried a different cable, NIC and drivers, do it can't be
that, but try anyway.)

The most likely cause given what you have said if that the Gigafast
and the BEFSR41 are not making nice with each other. In the old days,
we saw this problem with unswitched routers using longish cables and
more than three segments, for example: hub ------ hub ----- hub is
usually OK, but as soon as some non-technical individual segmented the
network further, we'd start to have problems. These were mostly due to
the latency involved in a multi-segmented non-switched collision based
LAN. In big offices, I sometimes had to put a router in the middle
just to divide the traffic.

With a switched 10/100 system, the problems are different, but the
symptoms may be the same. Switches don't send packets everywhere like
unswitched hubs used to do. That means that they have to figure out
where things go. ARP caches must be maintained, broadcasts much be
carried out, packets must be examined and things can go wrong leading
to increased latency. The Gigafast is a... (ahem) value product! It
may have some... (ahem) challenges figuring out that the packets
destined for the gaming software have to be switched through another
hub rather than directly to a NIC. This is pure speculation on my
part, but I think it is the first place to look.

Anyway, the obvious question is: What is the Gigafast doing there? If
there is a good answer to this, let me know and I'll have another
think.

Alan Kali

Here a few thing you should try and post the results

1: On all your computers (DOS PROMPT) type "ping 127.0.0.1" (ping
should be less that <10ms)

2: Now ping your other computers, from each other. (Should be <10ms)

Suggestions

Use static IP's i.e. 192.168.0.1,192.168.0.2 ect... with subnet 255.255.255.0

Type in your gateway (your broad band router/modem)

X

Shortywop,

You have covered everything obvious, so it is time to start thinking
laterally. There are three obvious sources of problems:

(1) The downstairs computer has a hardware problem. You've changed the
drivers, so it is probably not software, and you've changed the NIC so
it cannot be that. This leaves some kind of PCI or chipset problem -
very rare indeed producing the symptoms you describe, but not unheard
of. You haven't told us what hardware and NIC(s) you are using
downstairs. It could be important, so you should tell us. On balance
though, this probably aint it.

(2) A problem with ASE. I have been assuming that your ping times to
game servers were high, but that is a big mistake. ASE implements ICMP
differently from Windows 2000. You should note down the IP address of
the gamer servers not responding in ASE (assuming you can get that
far) and ping them manually from the Win2000 command prompt. See if
they are also high from the prompt. If they are, then you truly have a
high ping loss/latency problem. If not, then ASE is your problem.
Since the computer upstairs is working fine, and assuming you are
running the same version of ASE, then you have ASE misconfigured on
the downstairs machine. Perhaps you have forgotten to check the
"Broken Router" box in the Options - Network page of ASE on the
downstairs box. This is necessary with the BEFSR41. If you don't have
a "Broken Router" checkbox, make sure you are running v2.3.1 or
greater of ASE

(3) A protocol problem. This is less likely, since you should not have
to configure the BEFSR41 specially unless you are serving under ASE,
but there is a remote possibility of some wierdness. For example, you
could have a wacky packet filtering rule in place that allows ICMP
only to the upstairs machine. This is way out there, but that's the
territory we're moving toward.

If this doesn't fix it, can you tell us:
Hardware (downstairs & upstairs)
NIC models
ASE version
"Broken Router" checked?
Command prompt ping gives same results as ASE ping times?

Thanks,

Alan Kali

Some weirdness crept into that post, all right. I do know when to
break the "i before e rule" and I am not a gamer but a lamer when I
speak of "gamer servers", so please delete the "r".

Alan Kali

Oh, yes - on the network packet testing program. There are many great,
free network analyzers out there. Ethereal is the one I use, and I
used to use the Microsoft one that came with SMS.

Unfortunately, it is a lot of work setting up the filters for an
unknown problem, and it may not tell you anything, anyway. If you have
very high latency or packet loss, even a properly constructed filter
will probably just show you what you already know: pings are going out
and coming back late or not at all. Diagnosing ASE that way is going
to be even more challenging than looking for regular packet loss,
since the documentation for ASE is a little on the sparse side.
Creating your filters will be fun.

If the problem is somewhere in your computer or the BEFSR41, you won't
see that with a sniffer; you only get what's on the segment. You won't
see problems ascending or descending the layers at either end, and, of
course, you won't see the Internet traffic. Also, if stuff is getting
switched wrong (or slow) you won't see that, either, unless you run
the analyzer on each segment. In the case of a switched network, this
means every port. It used to be a lot easier in the old days.

In case you want to try it, here are some packet analyzer links:

http://www.ethereal.com/
http://www.analogx.com/contents/download/network/pmon.htm
http://netsecurity.about.com/cs/hackertools/a/aafreepacsniff.htm (links page)

Alan Kali

The fact that you are getting high ping times to the game servers from
the command prompt is great. It eliminates a problem with ASE
specifically, and it gives you a reproducible error - an excellent
diagnostic tool.

I cannot suggest strongly enough that each time you test an alternate
configuration, you standardize your testing conditions. Here are some
suggestions:

(1) Use a set of IP addresses that give consistently high ping times
downstairs and ping all of them from the command prompt.

(2) Make sure that there are no programs running when you do this -
especially ASE. Shut down anything in the system tray, and try to stop
unnecessary services.

(3) Check your autostarts and remove anything you do not need. Use
something like StartupRun v1.20 from http://nirsoft.mirrorz.com/ that
allows you to disable, rather than delete autostarts if you are not
sure about how to do this.

(4) Temporarily disable any firewall and virus scanner on the
downstairs computer. Make sure there is no built-in packet filtering
going on in the Win2000 network configuration settings.

(5) It will mean a lot of running upstairs, but you should compare
each result of a ping session from downstairs with exactly the same
procedure upstairs.

You have changed NICs and drivers, so it cannot be a hardware or
driver problem with the downstairs NIC. You are running the same OS
and service pack level as upstairs, so it cannot be the OS. You have
low ping times to servers on the LAN, so that all but eliminates the
possibility of a hardware problem on the Epox board. It is possible,
but very unlikely. Also, any settings for speed and duplex on the
downstairs NIC are likely to be unrelated, since an inappropriate
setting here would affect local as well as game server ping times.
Cables are out; you've changed them enough to be sure. Cable path
interference is out. You've tried that one.

The only logical conclusion is that pings are actually being lost or
delayed; that is what the downstairs machine is telling you, and at
this point I am inclined to believe it.

One of the chief methods of troubleshooting is to simplify the system
as much as possible while you test a reproducible error under standard
conditions as described above. You should take the network down to
just the downstairs machine --- BEFSR41 --- Internet and perform the
ping test from the command prompt. No other devices should be
installed: no Xbox, no Gigafast, no upstairs computer, nothing.
Confirm that pings are high in that configuration, then plug in the
upstairs computer and do the ping test there for a control. Then go
back downstairs and repeat the ping test to confirm that the results
have not changed.

If you get high ping times from the command prompt in this
configuration, then pings are most likely being delayed somewhere
beyond the NIC of the BEFSR41. Your upstairs machine gets through it
fine, so the only reasonable explanation is that you have a wacky
filtering rule on the BEFSR41 that is preferentially returning traffic
to the upstairs machine, or blocking traffic to the downstairs
machine.

I have to admit that I think this is an outside possibility. I suspect
that the problem is on the LAN, and that it has been difficult for you
to diagnose due to nonstandard testing. Whenever I have gotten to the
stage you have with a network problem, namely that it seems to defy
all common sense, I have found that the problem was me assuming
something without testing in a rigorous, standardized fashion.
Sometimes I have been so convinced of something that the problem
seemed to be supernatural; it never was - I just had to reexamine my
conclusions.

By the way, while I don't think it matters at this point because you
have probably eliminated these things, You are a little vague about
the hardware. When you say Realtek RTL1839, you must mean RTL8139.
Realtek makes chipsets. The card is probably a generic with a Realtek
chipset. Can you identify it further as a RTL8139C(L), RTL8139C(L)+ or
RTL8139D(L) chipset?

When you say you swapped out your 530TX, I assume you mean DFE-530TX+
(http://www.dlink.com/products/?pid=122).

And could you please tell us what is the model number of the Eox board
in the downstairs machine?

Best Regards,

Alan Kali

Shortywop,

One other thing: in testing just now, we have been able to reproduce a
problem where ASE ran, timed out, and then prevented the system from
pinging any hosts (both local and Internet) from the command prompt.
This occurred both during and after ASE was in operation, and resolved
by itself about a minute after ASE was terminated.

It is very important therefore that you make a list of high-ping time
servers in ASE, then ensure that ASE is not running and you have low
ping times to local machines - possibly even reboot before doing the
tests.

So far as I can tell, ASE is using up all network resources on the
local machine. This is only affecting one machine on our LAN: an
Emachines laptop that normally does not run ASE. ASE works fine
elsewhere, so this may mean that ASE has problems with certain
configurations.

Alan Kali

OK, so it is not just high ping times and ping packet loss. From your
latest post, it is a global failure affecting multiple protocols (TCP,
UDP and ICMP by the sounds of it). This is more likely a broken stack.

A broken stack can manifest in ways that are hard to pin down.
Sometimes small or single packets will get through, and large or
frequent packets won't. I suggest that you try moving a large volume
of data between the downstairs computer and the upstairs computer. See
if it gets corrupted or if packets get lost. There are several ways to
do this, and you should try as many as you can.

Set up a web server on the upstairs machine. AnalogX (at
http://www.analogx.com/contents/download/network/sswww.htm) have a
great one for this purpose. Make sure you set it up to serve a variety
of test data, including text as well as large and small images. If you
get the same errors as you have reported above, then you probably have
a broken TCP/IP stack on the downstairs machine.

You should also try FTP (http://smallftpd.sourceforge.net/) and SMB. I
would share a temporary directory on the upstairs machine and map it
from the downstairs machine, then transfer .zip or .rar files back and
forth. If the transfer hangs or fails, or if you test the archive
after transfer and find errors, once again it points to a broken stack
downstairs.

If these tests are negative, and the problem is confined to Internet
traffic, then it is more difficult to explain, given what you have
told us. In this case, you may want to make absolutely sure that you
have a standardized bare network testing setup as I described earlier
and confirm that the problem still exists.

Alan Kali