OT ... How can i find out if my NIC runs in Full/Half duplex

[LordCrush]

Hmm after 1 hr of googeling ... i just ask here if anyone has a tipp for me. I am not sure wether the NIC in my Linux-Box runs in half or full duplex mode. Fullduplex on a hub would not be the best 8))


Thank you in advance

-- LC

[S_B_R]

/sbin/mii-tool
output looks something like
eth0: negotiated 100baseTx-FD flow-control, link okFD means Full Duplex, HD would mean Half Duplex. mii-tool is also what you'd use to forcibly change the connection settings on the NIC.

[Cryonic]

Problem is, you can't run Full-Duplex on a hub.

Due to the nature of a hub (simple multiport repeater) all systems hooked to it are part of the same collision domain. So the Nic has to be in Half-Duplex mode to allow it to listen for incoming packets in an attempt to detect another device talking when it tries to talk.

Only switches can run full-duplex because on a switch each port is its own collision domain, so the Nic doesn't have to worry about stepping on another boxes toes when it starts up a conversation.

[LordCrush]

Thank you SBR ... worked fine 8))


and Cryo, i know this, but i have that much collisions on the hub and the NIC that i wanted to check the NIC settings, because i am still searching the reason why 5007 does not work for me 8/

Thanks anyway :D

[S_B_R]

Cryonic, not everyone that uses SEQ has a hub based network... I surely don't. ;)

[LordCrush]

SBR do you use Monitor Port or ARP-Injection ?

[S_B_R]

I run SEQ on my Firewall box, so I don't have to worry about hub/switch, and I don't need to run SEQ as a privileged user.

Internet
|
Linux Box
|
Switch/WirelessAP
| | !
EQ1 EQ2 WiFi
Laptop/EQ3

[Cryonic]

Originally posted by S_B_R
Cryonic, not everyone that uses SEQ has a hub based network... I surely don't. ;)

Nor do I. The hub I have is the last step off my network to the Net (so SEQ and a few other things work). The point was to point out that a NIC can't really get into full-duplex mode on a hub due to the nature of what a hub is/does. The reality is, if the NIC was in Full-duplex mode you would get a lot of frame errors on the hub and performance from that machine would be very degraded as would a lot of other traffic.

If you are seeing lots of collisions, then it just means your network is very noisy (lots of machines trying to talk) and could be resolved by moving machines off the hub and onto switches together (as that creates seperate collision domains for those machines).

[S_B_R]

I think what Lordcrush was getting at was he wanted to make sure his NIC wasn't in Fullduplex on his hub. Not that he wanted it to be Fullduplex on his hub.

[LordCrush]

Nod S_B_R,

atm i run two Linux-Boxes SUSE 7.2/SEQ 4.x and SUSE 9.0/SEQ 5.x and i connect via VNC to thease PCs to look at SEQ. SEQ 4.x works fine, but with SEQ 5.x i get only unknown spawns after some minutes.

My Networklayout looks like this:



Internet
|
Win2003 Server(Router/Firewall/VPN-Tunnel)
|
HUB
|
----------------------------------
| | | | | |
SWITCH SUSE 7.2 EQ1 EQ2 EQ3 SUSE 9.0
| (SEQ 4.x) (SEQ 5.x)
|
-----------------
| |
WINXP1 WINXP2 .. N (VNC)

and i have massive collisions on the HUB therefor i wanted to check the settings of the NICs, because i think the massive collisions are the reason that causes the unknowns with 5.x. Unfortunally i have not enough spare time atm to test it intensively.

/shrug

[S_B_R]

Try configuring you network like this:

Internet
|
Win2K3
|
----Hub----
| | |
| SEQ4 SEQ5
|
-------Switch-----------
| | | | |
WinXP1 EQ1 EQ2 EQ3 WinXP2

[high energy]

Wouldn't you want the hub after the switch? It would cause less collision at the source of your ISP.



Internet
|
FreeBSD
|
-----Switch-------------------------
| | | | | |
CPU1 CPU2 CPU3 CPU4 CPU5 --------HUB-----
| | | |
SEQ1 SEQ2 EQ1 EQ2

That way, the other computers on your network don't have to deal with the traffic that a hub forces upon it.

[Cryonic]

Uhh.... the PC between the hub and the Net connection stop any kind of collisions from his network impacting his ISP at all. Since most people don't have enough bandwidth to the Net to saturate even a 10Mb Half-Duplex connection it doesn't matter. Besides, pushing the EQ machines onto the switch is better since windows systems tend to be very network chatty.

[S_B_R]

Cryonic is exactly correct. Basically, you want to get as many machines on the switch as possible and still allow both SEQ boxes to see the EQ data streams.

The reason the SEQ systems are having problems is they are missing packets that the EQ machines are getting. This happens through collisions. Getting all the EQ PCs on the switch will result in having fewer places where a collision may occur.

The only thing that will cause collisions in the configuration I posted above, is the traffic being generated by the VNC sessions running on the SEQ boxes. If the 2 SEQ boxes weren't generating traffic (VNC) of thier own this setup would be nearly devoid of collisions.

[high energy]

SEQ requires a hub. A hub passes every bit of traffic to all devices connected to it. That's how SEQ works. A switch however, only sends the packets to the device its intended for. SEQ wouldn't be able to work in this environment because the switch isn't passing the EQ traffic to the SEQ machine.

While Cryonic is correct on the traffic "to" the internet, (most of us don't have a 100 megabit connection to the internet), I "believe" we all copy files across the network internally. I copy hundreds of gigs (not daily, but does occur on a single day now and then), across my internal network. So I believed that a switch would work better for me than a hub as I thought the switch only tranferred the traffic between the originator and the destination only. It didn't bother any other machine on the network like a hub does, where a hub would ping every single machine on the network for every packet asking it, "is this yours"?

Perhaps I'm missing something here.

[Cryonic]

In SBR's configuration, the hub only impacts the two SEQ machines and the Gateway device (in this case another Win box). All the other machines are on the switch and therefore can do 100Mb Full-Duplex. The switch will only send data to the hub when the destination MAC address in its lookup table matches a machine out the port going to the hub.

[S_B_R]

Yep, like I said the goal here is to get as many machines as possible on the Switch. Or another way of saying that is; the goal is to get as few machines as possible on the Hub.

Your method applied to LordCrush's situation would result in 5 machines on the hub. Mine has 3. If the SEQ machines weren't genetating traffic they would have no impact on the hub at all.

[monster69]

To further Cryonic's explanation,

All the trafic between SOE and the EQ client machines travels across the hub in SBR's diagram, therefore the SEQ machines can capture all those packets.

Monster

[high energy]

Right, no I understand that. So if the switch is plugged into the hub, the switch doesn't get hub traffic? Does the switch just ingore that data or does it try and figure out if that data belongs to it or not?

[S_B_R]

the switch works just like it always works. if the traffic on the hub is not directed to any of the PCs connect to the switch the switch will ignore those packets.

[Cleric]

high energy's diagram would be the best to reduce traffic on the HUB which should help with the collision issue.

That way the only traffic getting to the PCs on the HUB would be traffic related to the EQ PCs. In a configuration where the HUB comes first, ALL of the network traffic still passes through the HUB - by putting the HUB behind the switch you would significantly reduce the traffic on that segment and most likely reduce the collision problems.

S_B_R's setup would still have ALL the network traffic running through the HUB-even though only 2 computers are attached directly to the HUB, the traffic from all the other PCs behind the switch going through the HUB is still "seen" by the HUB.

[Cryonic]

SBRs setup only has traffic needing to get to the Net or the SEQ systems going out on the hub.

High Energy's puts any traffic going from the EQ machines to any of the other Windows boxes onto the hub.

I don't know, but I'm guessing most users here use their EQ systems for more than just EQ. I'm constantly streaming traffic from one system to another, but only need a very insignificant fraction of that traffic to saturate my Net connection. So, putting the hub right next to the router only impacts what is going to/from the Net and since the amount of traffic their is significantly less than the 10Mb Half-Duplex that my hub runs at (compare 5Mb ethernet to 640kb DSL) and you can see how much bandwidth is to spare before I really start to have collisions and traffic issues).

Or, do away with the hub entirely and use the SEQ box as the firewall/gateway to the Net.

[S_B_R]

In the topology I posted, only the traffic to and from the INTERNET will be seen by the SEQ systems ( aside from any traffic generated by the SEQ themselves, but that will be there anyway).

Any traffic between the other WinXP and EQ machines will be segmented away from the SEQ systems. The Switch will keep the traffic behind the switch from causing collisions on the hub.

In effect, the Topology Lordcrush posted originally is basically the same as what High Energy posted with the EQ and SEQ boxes together on the hub. The topology I posted segments all the high bandwitdh traffic onto the switch. only the lowbandwidth (Internet) traffic wil be broadcast on the hub.

But I'm almost 100% sure this is all a null issue because it's most likely the VNC traffic that's causing the majority of the collisions. And that traffic will be there no matter what the topology.

[LordCrush]

I have changed the layout to S_B_R´s Topology, (sometimes things are easy, but not easy to see 8) )

Unfortuanlly it did not solve the problem with the collisions. I think that the VNC-Host / Viewer is very chatty.

I will try to replace this with the Cygwin X-Server :)

[LordCrush]

Originally posted by S_B_R

/sbin/mii-tool
output looks something like
eth0: negotiated 100baseTx-FD flow-control, link okFD means Full Duplex, HD would mean Half Duplex. mii-tool is also what you'd use to forcibly change the connection settings on the NIC.

In Suse 9.0 you need to use



ethtool eth0

[S_B_R]

Yeah, sorry about that I should have asked what distro... If you're using Fedora (any build as far as I know) mii-tool doesn't work at all, and ethtool is hit or miss.

[LordCrush]

No need to be sorry about that .. it helped me to find the right command on google :D

Btw with 7.2 mii-tool works :)

[Psylenced]

Sorry to piggyback off of someone elses thread but its directly related.

My current network setup set up is:

(internet)
|
|
(Windows XP Pro with 2 nics & EverQuest installed)
| |
| |
(Gentoo Linux Box running SEQ) |
|
|
(D-Link DI-??? Router)
|
|
(WinXP Pro PC)
(Not used for anything relevant)


Would this work with SEQ? The reasoning behind the Router and one machine behind it is that my Intel InBusiness hub died on me, and I couldnt find another hub at any of the local stores for the life of me. Being impatient and willing to spend the extra money i just bought a router instead. Besides it will come in handy when I get broadband and more PC's. I havent installed SEQ yet, but will be when I get home, I didnt have an extra linux box that would run it efficiently until recently.

[Psylenced]

My bad, forgot to use code tags, layout is as follows:



(internet)
|
|
(Windows XP Pro with 2 nics & EverQuest installed)
| |
| |
(Gentoo Linux Box running SEQ) |
|
|
(D-Link DI-??? Router)
|
|
(WinXP Pro PC)
(Not used for anything relevant)


So would this network topology work? Or would my Gentoox box not be able to monitor the PC's traffic being directly connected to it?

[S_B_R]

Nope wont work at all, SEQ won't see any traffic at all.

[Psylenced]

If I moved the linux box behind the DI-??? Router would it work? What exactly in this topology makes it not work? Forgive me for my inexperience with networking traffic protocols.

[S_B_R]

Easiest way to think about it is. figure out where the EQ traffic is coming from and going to, the source and destination. Now understand the network traffic is going to take the shortest route it can between the source and the destination.

Next think about your topology. Which path is the shortest to get from your EQ machine to the internet? Since your EQ machine sits directly connected to the internet that's the route it's going to take. Since your SEQ box is not in between your EQ box and the internet, along that shortest route, it has no chance to see any of that traffic.

[Psylenced]

Ok so if I move the linux box to the front of the topology and use it as my internet gateway it would work then.

What If used the second PC as the gateway and plugged my EQ PC and linux box into the D-Link router? I know routers forward packets intelligently but would it be possible to change the settings on the router to just make it a dummy hub?

Would really like to get SEQ up and running but rewiring my network involves rerunning several hundred feet of cable haha, the PC's are in different area's of the house. I'll do it if I have to, but would like to excercise any other available options first :)

Thanks a ton for the help!

[S_B_R]

Ok so if I move the linux box to the front of the topology and use it as my internet gateway it would work then.Correct. IMHO that is the best way to run SEQ.
What If used the second PC as the gateway and plugged my EQ PC and linux box into the D-Link router? I know routers forward packets intelligently but would it be possible to change the settings on the router to just make it a dummy hub?You'd have to determine if your router is capable of doing such a thing. I'd say you can pretty much bet on it will not function that way. Your best bet in this scenario would be to replace the Router with a "Dumb Hub"