Network dies after unknown idle period - F16 on new PC build

[dwsideri]

I am having some network issues with a custom-built PC running Fedora 16. I have run F16 on a different PC since its release in 2011 and have not had network problems, so I think this may be a software-hardware interaction problem.

Here's what happens: When my PC sits idle for some time (overnight, sometimes just a few hours, I haven't found a pattern yet), the network just dies. I cannot ping hosts (even inside my subnet), traceroute anything, nothing. Running "systemctl restart network" returns a successful "OK", but it does not restore actual network access. I have to restart the OS to restore an active network connection

One way I have found to prevent this is to run a media stream overnight; as long as the stream does not disconnect randomly, this preserves the network connection. The other thing I tried was running a cron script every 30 minutes that runs a traceroute (just to google.com), but this did not prevent the network from dying. (I reduced that to 15 minutes, but haven't been able to test it over a long period yet.)

Any thoughts on where to look or changes to make? I keep an eye on /var/log/messages, but have not been able to identify an error message associated with the network dying.

Hardware:
ASUS PZ868-M Pro Motherboard (onboard NIC), Intel Z68 chipset
Intel i5-2500K CPU

Software:
Fairly vanilla install of F16, I keep the kernel up to date.

The motherboard has a UEFI BIOS and I turned off the power saving features.

[PabloTwo]

A F16 install defaults to using the NetworkManager.service for it's networking. You didn't mention in your post whether you or not you have disabled the NetworkManager service and enabled the network service instead. So, my question to you would be, which is running at bootup on your system, NetworkManager or network?

If NetworkManager is running at bootup, then doing "systemctl restart network" won't really do anything to get you back online (thus the need for a reboot). If you're actually using NetworkManager, then after the next network dropout, you might try, "systemctl restart NetworkManager.service".

[dwsideri]

PabloTwo, thanks for the info. A quick check of "systemctl status NetworkManager.service" does tell me that it is running and managing the network connection. Plus, I did not make any changes to the network management during the F16 install, so it should be running by default.

I'll try the "systemctl restart NetworkManager.service" test the next time the network dies, probably overnight tonight.

[jpollard]

You can always try disabling NetworkManager and enabling network. NetworkManager just doesn't work properly.

That is what I had to do to get things working correctly with VMs on F16.

note: you do have to do a network restart afterwards (or reboot).

[PabloTwo]

You also don't mention whether you're using a wired or wireless connection, or the chipset(s) of your network devices. There are many threads on this forum about various network devices that "drop the network connection after a period of time". Maybe you have one of those devices (?). The fixes (if there is one) for some of those issues varies depending on which hardware device is concerned. Sometimes blacklisting a certain kernel module from loading, or blacklisting the default Fedora supplied kmod driver(s) and/or firmware for the device and using drivers available from rpmfusion repos. Just I'd mention this as this may be where you're headed for a "fix".

As an aside: the "network" service is still provided as a SysVInit type of service, rather than being converted over to the systemd (systemctl) style of services control. So the proper way of dealing with the "network" service is the old way, using the "service" and "chkconfig" commands. You can see the services still served up under the old SysVInit umbrella by issuing the "chkconfig --list" command.

[dwsideri]

More details:

My network is provided by a wired connection to the NIC. The chipset of the NIC is a Realtek 8111E, `lspci` states that it is the Realtek RTL8111/8168B ethernet controller.

That ethernet controller shows up as problematic in old posts, but I have not found any posts that specifically mention the network dropping after some idle time. I'll continue investigating.

[PabloTwo]

I'm using the same NIC chipset as you are.

BASH:~/-> lspci | grep -i net
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 06)

I have never had any issue with it dropping my network connection. But then, I never leave my computer on for any extended period of non-use. When I'm done using it, I turn it off.