[SOLVED] direct PC to PC connection issue

art84 · 2010-12-12 16:18:03

Hi

I have the following configuration:

* PC1: Win32 XP, onboard integrated Gbit NIC Vitesse VSC8201RX [ Fully IEEE 802.3, 802.3u (10BASE-T, 100BASE-TX) & 802.3ab (1000BASE-T) Compliant; Automatic Detection and Correction of Cable Pair Swaps, Pair Skew, and Pair Polarity, Along with Auto MDI/MDI-X Crossover Function; Autonegotiation/Full Duplex flow control/Jumbo frames/etc. ]
IP 192.168.1.1

* PC2: Arch Linux 2010.05, onboard integrated Gbit NIC Realtek RTL8111DL (also used as RTL8168) [ Fully compliant with IEEE 802.3, IEEE 802.3u, IEEE 802.3ab; Supports pair swap/polarity/skew correction; Crossover Detection & Auto-Correction; Autonegotiation/Full Duplex flow control/Jumbo frames/etc. ]
IP 192.168.1.2

* computers are connected directly through a "patch cable" (not a cross-over one), but both NIC supports auto MDI/MDI-X (crossover detection and correction) so it must be OK from this point of view

On Arch it was used module r8169, but I've built and installed a more appropiate r8168 module.
Well, it works fine with both modules r8169 and r8168 ... but only at max. 100 Mbps speed.
When I set "autonegotiation" ON on both NICs, the Win32 PC shows a 1 Gbit connection tray tooltip for a half of a second then it switches to "network cable is unplugged", then it show again 1 Gbit tray tooltip, then again "network cable is unplugged" and so on.

The Win32 PC was in a Gbit network for a while and it operated at 1 Gbit speed, so all the suspicions are related to Arch system with its RTL 8111DL NIC.

Could someone help or explain me what to do to have a 1 Gbit connection? Any help/ideas will be very appreciated.
Maybe it's even not a win/Linux issue and I'm doing smth conceptually wrong? Or a Gbit connection could be establiched only using a switch/hub? Or maybe some conflicts when autonegotiating and it mus be set up somehow?
Thank you in advance.

P.S. if "hardware" or "networking" forum branches are better places for this thread, feel free to move it there .. thank you

Last edited by art84 (2010-12-19 16:53:54)

hexanol · 2010-12-12 16:35:34

The cable plugged in, you can try using ethtool (in the ethtool package) to display various information and see if there's something wrong.

That said, I don't have any solution to your problem.

art84 · 2010-12-12 16:50:53

hexanol, thank you for your help, but I've used "ethtool" and no success
ethtool reports 5 modes: 10 HD, 10 FD, 100 HD, 100 FD, and 1000 FD
it also reports the current speed, autonegotiation status, etc.
for 10 and 100 it works well

I know that 1000BASE-T standard requires autonegotiation to be enables, so I've tried:

ethtool -s eth0 autoneg on speed 1000 duplex full

maybe there must be an "algorithm" to enable the 1 Gbit connection? maybe there are some issues with MASTER/SLAVE autonegotiation modes of the NICs?
at least, how does it work theoretically (not depdening on OS)? enable "autonegotiation" on both NICs and they must choose 1 Gbit if both support?

Last edited by art84 (2010-12-12 16:51:34)

hexanol · 2010-12-12 17:04:47

Well, yes, that's usually how it works.

And from the output of ethtool, does the link partner (i.e. the Windows box) advertise 1000BaseT/Full ? And did you try with another cable ?

graysky · 2010-12-12 17:18:57

art84 wrote:

* computers are connected directly through a "patch cable" (not a cross-over one), but both NIC supports auto MDI/MDI-X (crossover detection and correction) so it must be OK from this point of view

The only time I've done this is with a cross over cable, not a straight-through cable. Dunno if that makes a difference for your case or not. Other thing you can do is to pick up a gigabit switch to rule out the cable thing. 5-port ones are under $50. I have a netgear GS-108 for years that's on 24/7.

Last edited by graysky (2010-12-12 17:22:55)

art84 · 2010-12-12 17:51:50

hexanol,

the cable is Cat-5e and it works fine at 100 Mbps (yes, I know, 10/100 Mpbs uses 4 wires from 8, so there is a chance that it's something wrong with other 4 wires when trying to use 8)
and how can I see what speeds my link partner (win's NIC) advertises?

ethtool says the following about Arch's NIC:

Supported ports: [TP ]
Supported link modes:  10baseT/Half  10baseT/Full
                       100baseT/Half  100baseT/Full
                       1000baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half  10baseT/Full
                       100baseT/Half  100baseT/Full
                       1000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes
...
Port: Twisted Pair
MDI-X: unknown
...

graysky,
thank you for your proposal, but I would like to solve it without spending 50$ (in my country for some people 50$ are a monthly salary)

hexanol · 2010-12-12 18:21:33

[root@victor ~]# ethtool eth0
Settings for eth0:
    Supported ports: [ TP MII ]
    Supported link modes:   10baseT/Half 10baseT/Full 
                            100baseT/Half 100baseT/Full 
                            1000baseT/Half 1000baseT/Full 
    Supports auto-negotiation: Yes
    Advertised link modes:  10baseT/Half 10baseT/Full 
                            100baseT/Half 100baseT/Full 
                            1000baseT/Half 1000baseT/Full 
    Advertised pause frame use: No
    Advertised auto-negotiation: Yes
    Link partner advertised link modes:  10baseT/Half 10baseT/Full 
                                         100baseT/Half 100baseT/Full 
    Link partner advertised pause frame use: No
    Link partner advertised auto-negotiation: Yes
    Speed: 100Mb/s
    Duplex: Full
    Port: MII
    PHYAD: 0
    Transceiver: internal
    Auto-negotiation: on
    Supports Wake-on: pumbg
    Wake-on: d
    Current message level: 0x00000033 (51)
                   drv probe ifdown ifup
    Link detected: yes

My NIC is an RTL8111B, and I'm using the r8169 module. I'm connected to a 100 Mbit/s switch. See the 'link partner advertised link modes' ?

art84 · 2010-12-12 18:57:45

for every test I'm using r8169 on Arch

Firstly, on Win I select "Full Autonegotiation" from the speed list:

[root@zion ~]# ethtool eth0
Settings for eth0:
    Supported ports: [ TP MII ]
    Supported link modes:   10baseT/Half 10baseT/Full 
                            100baseT/Half 100baseT/Full 
                            1000baseT/Half 1000baseT/Full 
    Supports auto-negotiation: Yes
    Advertised link modes:  10baseT/Half 10baseT/Full 
                            100baseT/Half 100baseT/Full 
                            1000baseT/Half 1000baseT/Full 
    Advertised pause frame use: No
    Advertised auto-negotiation: Yes
    Speed: 100Mb/s
    Duplex: Full
    Port: MII
    PHYAD: 0
    Transceiver: internal
    Auto-negotiation: on
    Supports Wake-on: pumbg
    Wake-on: d
    Current message level: 0x00000033 (51)
                   drv probe ifdown ifup
    Link detected: no

(exactly the as yours without "partner" fields and no link)
when this "Full Autonegotiation" is activated, the Win PC permanently pops up tray tooltips with "Speed 1 Gbps" for a short moment (half a second maybe or less) then "A network cable is unplugged" again adn again

when I set "Autonegotiate for 100HD" / ""Autonegotiate for 100FD" / "Autonegotiate for 10HD" / "Autonegotiate for 10FD" I get those "partner" fields like in your output and every time only one value for link modes: 100baseT/Half, 100baseT/Full, 10baseT/Half, 10baseT/Full respectively

when I set "Autonegotiate for 1000FD" I get no "partner" fields at all and "Link detected" cahnges to "no", so the connection is dead and doesn't do anything

Last edited by art84 (2010-12-12 18:58:36)

hexanol · 2010-12-12 22:28:53

At that point, I suspect some kind of driver issue or incompatibility (which would be surprising, but we never really know...). I can't help you more.

Good luck .

defears · 2010-12-13 02:15:08

You do need a crossover cable if 2 pc's are connected with no router or switch and has to be cat6 cable for true gigabit connection. Yes all cat5 or 6 cables use 4 of th 8 wires but in a crossover cable they are crossed. The conectors are called tia-a and tia-b or something. A to a and b to b are a normal patch cable but a cross over is a to b.

http://www.cctvcamerapros.com/v/vspfile … iagram.jpg

graysky · 2010-12-13 11:21:05

defears wrote:

You do need a crossover cable if 2 pc's are connected with no router or switch and has to be cat6 cable for true gigabit connection.

Hmm... there's an echo in here

graysky wrote:

The only time I've done this is with a cross over cable, not a straight-through cable. Dunno if that makes a difference for your case or not.

art84 · 2010-12-13 17:32:32

defears

thanks for this observations and help, but as I wrote manufacturers of both NICs advertise "Automatic Detection and Correction of Cable Pair Swaps, Pair Skew, and Pair Polarity, Along with Auto MDI/MDI-X Crossover Function" and if I'm not wrong, this is a 'hardware feature' which works independently
and they work for 10 Mbps and 100 Mbps using the same cable, so NICs do crossover correction at least for these 2 modes

if the cable is the problem, the only chance is that 4 wires used for 10/100 are OK, but another 4 used for 1000 (1000base-T requires all 8 wires from a Cat 5e cable) have issues

defears · 2010-12-14 01:56:32

greysky
Sorry, I type real,real,real, slow :-)

art84
Maybe the auto configuration only works on windows. The MDI-X unknown sounds like it's a software problem. I install miles of cat5 and 6 at work, but I never had a problem with a crossover cable for any os. Perhaps you could borrow someone's cat5 crimp tool and make your own cable. Then you only need 1 connector and your patch cable. Not much money.

art84 · 2010-12-19 16:53:36

found what was wrong: the Vitesse VSC8201RX Gbit NIC works incorrectly
bought a new Gbit NIC (RealTek 8169) and I've got my Gbit connection .. Arch woks well, but reached only 18 MB/s ... hoped for at least 50 MB/s
one more time, thanks go to everyone who tried to help me

marked as 'SOLVED'

graysky · 2010-12-19 18:44:42

@art84 - 18 MB/s???? What kind of HDDs do you have? That seems WAY low. On my system sharing with NFSv4, xfer speeds approach the disk-to-disk speeds (SATA2/7200 RPM). Try testing your network like this: http://openmaniak.com/iperf.php

For reference, my setup gives about 945 Mbits/sec on a 1.1 GByte transfer.

art84 · 2010-12-20 16:14:18

both PCs have relatively new and quick HDDs: Samsung SpinPoint F3 500 GB @ 7200rpm (both PC have the same model)
HDD benchmarks give 115 MB/s avg (75 MB/s min & 140 MB/s max.), so at least 75 MB/s HDD must sustain.

I'm also considering that PCI bus could diminish the final (real) speed, because on the first PC the NIC (RealTek 8169) is external and it's connected to simple PCI which has a shared bandwidth of 133 MB/s. Anyway, I don't have other cards installed on that PC and I don't think that only 18 from 133 are available
The second PC (with Arch) has an intergated NIC (RealTek 8111DL also identidied as 8168) connected to PCI-Express, so it has 250 MB/s.

graysky · 2010-12-20 17:11:49

@art - okay. What speed did you get on the iperf tests?

art84 · 2010-12-20 17:49:31

iperf server running on Arch PC (iperf -s)
launching client on win PC:

C:\tmp\iperf-2.0.5-cygwin>iperf -d -c 192.168.1.2
WARNING: option -d is not valid for server mode
------------------------------------------------------------
Client connecting to 192.168.1.2, TCP port 5001
TCP window size: 64.0 KByte (default)
------------------------------------------------------------
[  3] local 192.168.1.1 port 3007 connected with 192.168.1.2 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec   357 MBytes   297 Mbits/sec

Last edited by art84 (2010-12-20 17:51:17)

Arch Linux

#1 2010-12-12 16:18:03

[SOLVED] direct PC to PC connection issue

#2 2010-12-12 16:35:34

Re: [SOLVED] direct PC to PC connection issue

#3 2010-12-12 16:50:53

Re: [SOLVED] direct PC to PC connection issue

#4 2010-12-12 17:04:47

Re: [SOLVED] direct PC to PC connection issue

#5 2010-12-12 17:18:57

Re: [SOLVED] direct PC to PC connection issue

#6 2010-12-12 17:51:50

Re: [SOLVED] direct PC to PC connection issue

#7 2010-12-12 18:21:33

Re: [SOLVED] direct PC to PC connection issue

#8 2010-12-12 18:57:45

Re: [SOLVED] direct PC to PC connection issue

#9 2010-12-12 22:28:53

Re: [SOLVED] direct PC to PC connection issue

#10 2010-12-13 02:15:08

Re: [SOLVED] direct PC to PC connection issue

#11 2010-12-13 11:21:05

Re: [SOLVED] direct PC to PC connection issue

#12 2010-12-13 17:32:32

Re: [SOLVED] direct PC to PC connection issue

#13 2010-12-14 01:56:32

Re: [SOLVED] direct PC to PC connection issue

#14 2010-12-19 16:53:36

Re: [SOLVED] direct PC to PC connection issue

#15 2010-12-19 18:44:42

Re: [SOLVED] direct PC to PC connection issue

#16 2010-12-20 16:14:18

Re: [SOLVED] direct PC to PC connection issue

#17 2010-12-20 17:11:49

Re: [SOLVED] direct PC to PC connection issue

#18 2010-12-20 17:49:31

Re: [SOLVED] direct PC to PC connection issue

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