ethernet - strange problem

[SentinelAeon]

Hello, i seem to have a strange problem on my main pc. If i plug in ethernet cable, i will still have the ethernet icon red crossed, like if the cable is not plugged in. That will last over 1 minute before slowly turning into yellow exclamation mark and then 20 seconds later finaly i will be connected to internet. I just tried my laptop and there, the laptop is connected to internet basicaly 5 seconds after i plug in the ethernet cable. So clearly it has something to do with my motherboards network card or software.

Im using P8Z77-V LX with windows 8.1 (i know .. i will switch soon) with official drivers. As for the settings, i dont even know where to start because i never had such problem before.

 

[kilo]

What's Happening on the network is the following:

1) Your computer is physically connected (layer 1)
2) Computer eth driver responds to the connection and sends broadcast (layer 2) looking for the DHCP server on your LAN (enterprise solutions have IPHelper solutions for this, I will spare you).
3) Your DHCP server, usually your home router, picks up the broadcast and sends a response (more here as well, don't worry too much).
4) Your computer receives the DHCP lease and has a IP address, Subnet Mask, Router (default gateway) address, and sometimes DNS as well (layer 3).
5) Your computer with its new IP address then pings MS servers on the internet to verify connection. This is when the icon in the system tray changes.

From what you describe, its working but not as fast as another computer on the same LAN. I wouldn't consider this to be a problem if convergence takes a little longer for another computer.

If it's a desktop and permanently connected to the network, you can speed up times with a static IP address, but that will require manual changes each time you change networks on the same NIC. It will be "faster" since no convergence is happening, but would require troubleshooting if the computer moves and you forget.

 

[thewan]

Your mobo comes with a Realtek RTL8111E for ethernet. This particular Realtek chip is known to be very picky with ethernet cables. If you just happened to have a cable that it "doesn't like" this is how it behaves. It has issues auto negotiating speeds on these cables. Its either really slow at doing so, negotiating the wrong speeds, or even worse both. Can you check what speeds your mobo is connecting? If its at the wrong speed sometimes or all the time even (example you have a gigabit network with gigabit capable wiring and router, but your PC only connects at 100Mb), this confirms that you are having the above issue.

Another way to confirm is if you can check what ethernet chip your Laptop is using. If its a different brand, Qualcomm, Intel, Broadcomm, etc, or even a newer Realtek one, and it has no issues quickly negotiating the correct speed, then yes you have the above issue.

At this point there is nothing you can do besides just living with the problem or buying a replacement ethernet adapter for your motherboard that isn't based on the RTL8111E. And make sure your future system doesn't use the RTL8111E. And also make sure it doesn't use the Intel 2.5 i225 or maybe i226 either. Those have the same problems. Either get one with the older Intel Gigabit or newer Realtek 2.5G based ones.

The above is my personal experience, not info I got from somewhere else.

Additional advice: Or you can rip out your ethernet network wiring and replace it with a different brand cable.

 

[pavle]

That icon is known to be slow to respond, so don't worry, as long as the network works, it doesn't matter.

 

[LabRat 891]

That icon is known to be slow to respond, so don't worry, as long as the network works, it doesn't matter.

In other words:

Please don't strongly interpret the dot Network Icon!

OTOH, the symptoms remind me of an 'out-of-spec but working' ethernet cable (lost twists, kinks, etc.) or poor ElectroMagnetic Compatibility on the NIC's side. If it were me, I'd be on the lookout for one of the firesales on CAT7, CAT7A, or CAT8 cables of whatever length you need (typ. $1.99-$20 for pre-made 1m-30m shielded and foiled twisted pair 4p8c terminated w/ a shielded RJ45).
Ignore the 'category' IEEE TIA whatever shenanigans and controversy.
You want a cable advertised as one of these 'vaguely-a-standard' specifications, as it's a cheap way to get decent to extremely well shielded cables. Even 'total scam' CAT7/7A/8 cable, should at least be 'dressed-up' FTP or STP CAT5/5E. Ideally, you do want actual copper (and solid instead of stranded), but Copper Clad Aluminum will do fine if you're not on/in the coast/rain forest, and/or running PoE.
Just having the cable to your rig mitigating some EMI can help. Where I live, any length of anything conductive, picks up several volts AC. Having shielding pull that to ground, can help a lot.

edit: I probably should recommend cleanly uninstalling, rebooting, and re-installing either the latest or second-latest driver for your NIC, too.
I've had all sorts of problems with an Intel NIC on an Asus Z77 ITX board; even updated to the latest driver. Had to uninstall it and treat it like I freshly installed the (integrated) NIC. Also fixed MANY a malfunctioning NIC and WiFi card on customer's PCs by simply cleanly reinstalling the driver.
edit2: Here's a link to the 1st party drivers. I've also had luck with this (frankly, sketchy) site. No idea why, but I have found drivers for old boards there, that somehow seemed to work better than RTL's 1st party.
According to to your mobo's manual, you have an RTL8111E / RTL8111F
Yet, Asus' support site supplies Intel NIC drivers for your board .

Interestingly enough, Intel does host Win 8.1 drivers for RTL8111 variants for several NUCs:

Realtek* Gigabit Ethernet Network Driver for Windows 8* and 8.1* for Intel® NUC - Realtek 8111GN-CG -Version: 8.020.0815.2013
Realtek* Gigabit Ethernet Network Driver for Windows 8.1* for NUC5CPYH, NUC5PPYH - Realtek 8111HN - Version: 8.38.115.2015

Last 'software' direction I'd go, would be to try and force install Lenovo, Dell, or HP drivers for the RTL8111. A couple of times professionally, and at least once on my own kit, I have had luck using an OEM's driver, as it seemingly had 'fixes' for issues owners of those systems may have actively complained of.

 

[SentinelAeon]

Tnx for all the replies, in the meantime i came to the same conclusion that it must be the cable. I actualy went and played with the cable a bit and now it seems to be in a position when it connects very fast. Also i do have the problem with wrong speed occasionaly ! I am on 100Mb line and occasionaly it will drop to 10Mb and i need to disable/enable the adapter. The cable is a few meters long. I will try another cable, maybe not the cheapest one like this time. I hope it works !

 

[LabRat 891]

Tnx for all the replies, in the meantime i came to the same conclusion that it must be the cable. I actualy went and played with the cable a bit and now it seems to be in a position when it connects very fast. Also i do have the problem with wrong speed occasionaly ! I am on 100Mb line and occasionaly it will drop to 10Mb and i need to disable/enable the adapter. The cable is a few meters long. I will try another cable, maybe not the cheapest one like this time. I hope it works !

You're 'dropping pairs'. The conductors are probably stressed fractured from bending/pinching. It happens. More often than not, you just need to snip off a few cm / in. and re-terminate the patch cable.

Depending on your precise flavor of 'thriftiness' I have a suggestion for at least 2:

1. Getting some RJ45 crimp-ons and the tool is a worthwhile investment. (even the Harbor Freight and 'import' tools are typically at least "serviceable")
BTW, you can use either TIA-spec (for wiring the pairs); just make sure it's the same on both ends. (While I do not recommend purposely messing things up, as long as both ends are the same, the NIC and Router / Switch will 'negotiate' in most cases.)
Tip: use the snipped-off ends as a 1:1 guide for the new termination. (most are clear plastic)

2.Keep an eye out on eBay, etc. for 'Field Termination' or 'tool-less' RJ45 or '4p8c' and buy surplus ones on the cheap.
They're more bulky, but much tougher (rougher on RJ45 jacks too), but need no tools other than a Leatherman (multi-tool) or pocket knife/razor.
They're reusable too! -you get multiple tries w/o wasted crimp-ons.

Either direction, you'll have stuff on-hand for making and fixing Ethernet cables. THAT is really handy.
plus you can save a lot of copper and PVC making its way into the trash in refurbishing old cables.


Sidenote: IIRC US retail chain hardware stores Lowe's and Home Depot aren't bad on pre-made cable pricing.
(Figured I'd add, since depending on living circumstances, this might be an option)