Weird issues with laptop lan.

[megosdog]

For those of you following my previous post about Synergy (https://www.kubuntuforums.net/showth...-with-Synergy/), you may remember that I began to isolate the issue and believed that a majority of the problem was the network. Well, today proved that point very solidly.

01:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter

This is the network card I have built into the laptop. I'm not really sure what driver or version I'm using for it, but I've pretty much 100% identified this as the cause. I'm not certain what to do to troubleshoot this, but I will describe what I saw that leads me to this assessment. Anyhow, I was watching the live stream of the SpaceX Dragon capsule return and partway through that broadcast the network card had several moments where data began to stutter, followed by a crash and reset of the network card that restored the connection. My desktop, which was streaming the same thing, did not have that issue, and the stream continued to play with no issues. So I know it's not my network itself having the issues. This crash occurred several times in a row, but with no real pattern or regularity. Just kinda outta the blue crashes where data is still moving to the nic, but nothing is getting to the OS. OR, if it is getting to the OS, it's corrupted from what I can tell. So my thought is possibly bad drivers, but that's only a guess.

Anyhow, if anyone can give me ideas on how to further troubleshoot this, I'd be greatly appreciative. Thanks.

[jglen490]

You could run

hwinfo --network

or

sudo lshw -C network

to verify what the driver is, but RTL8723BE PCIe Wireless Network Adapter appears to be an 802.11 bgn wifi card and as such is kinda limited in capability. I don't know if that is your network problem, or if it's the router, or some other hardware issue on board the PC. But if you are pretty certain that data is lost after the network, then you may want to consider doing something else since that wifi card seems a bit dated. A far as I can see there is no newer driver. but you might check with

ubuntu-drivers devices

on the command line and see if there is any recommendations.

[megosdog]

raiden@raiden:~$ hwinfo --network       
37: None 00.0: 10701 Ethernet                                   
 [Created at net.126]
 Unique ID: Ij4C.ndpeucax6V1
 Parent ID: c3qJ.2IqZ5ReWSKA
 SysFS ID: /class/net/enp2s0
 SysFS Device Link: /devices/pci0000:00/0000:00:02.4/0000:02:00.0
 Hardware Class: network interface
 Model: "Ethernet network interface"
 Driver: "r8169"
 Driver Modules: "r8169"
 Device File: enp2s0
 HW Address: dc:fe:07:29:72:d2
 Permanent HW Address: dc:fe:07:29:72:d2
 Link detected: yes
 Config Status: cfg=new, avail=yes, need=no, active=unknown
 Attached to: #7 (Ethernet controller)

38: None 00.0: 10700 Loopback
 [Created at net.126]
 Unique ID: ZsBS.GQNx7L4uPNA
 SysFS ID: /class/net/lo
 Hardware Class: network interface
 Model: "Loopback network interface"
 Device File: lo
 Link detected: yes
 Config Status: cfg=new, avail=yes, need=no, active=unknown

39: None 00.0: 10701 Ethernet
 [Created at net.126]
 Unique ID: eAgB.ndpeucax6V1
 Parent ID: yWPJ.H9ie4rG8dmC
 SysFS ID: /class/net/wlp1s0
 SysFS Device Link: /devices/pci0000:00/0000:00:02.3/0000:01:00.0
 Hardware Class: network interface
 Model: "Ethernet network interface"
 Driver: "rtl8723be"
 Driver Modules: "rtl8723be"
 Device File: wlp1s0
 HW Address: 4c:bb:58:fa:e5:35
 Permanent HW Address: 4c:bb:58:fa:e5:35
 Link detected: no
 Config Status: cfg=new, avail=yes, need=no, active=unknown
 Attached to: #12 (Ethernet controller)

I'm actually using the wired connection. I don't trust Wifi at all. Way too insecure for what I do.

raiden@raiden:~$ sudo lshw -C network
 *-network DISABLED        
      description: Wireless interface
      product: RTL8723BE PCIe Wireless Network Adapter
      vendor: Realtek Semiconductor Co., Ltd.
      physical id: 0
      bus info: pci@0000:01:00.0
      logical name: wlp1s0
      version: 00
      serial: 4c:bb:58:fa:e5:35
      width: 64 bits
      clock: 33MHz
      capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
      configuration: broadcast=yes driver=rtl8723be driverversion=5.4.0-42-generic firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11
      resources: irq:46 ioport:e000(size=256) memory:fea00000-fea03fff
 *-network
      description: Ethernet interface
      product: RTL810xE PCI Express Fast Ethernet controller
      vendor: Realtek Semiconductor Co., Ltd.
      physical id: 0
      bus info: pci@0000:02:00.0
      logical name: enp2s0
      version: 07
      serial: dc:fe:07:29:72:d2
      size: 100Mbit/s
      capacity: 100Mbit/s
      width: 64 bits
      clock: 33MHz
      capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
      configuration: autonegotiation=on broadcast=yes driver=r8169 duplex=full firmware=rtl8106e-1_0.0.1 06/29/12 ip=192.168.0.2 latency=0 link=yes multicast=yes port=MII speed=100Mbit/s
      resources: irq:37 ioport:d000(size=256) memory:fe900000-fe900fff memory:f0800000-f0803fff

The third one gave me nothing. Also, I just realized I gave you the wifi nic and not the ethernet, which is what I'm actually using. Here's what it says for that:

02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL810xE PCI Express Fast Ethernet controller (rev 07)

[megosdog]

Anyone got an answer for me? I mean, this isn't a show stopper, but it is super annoying, so I'd love to be able to fix this whenever possible. Thanks.

[jlittle]

I don't have any specific knowledge or experience about the Realtek, but you've encouraged me to speak up, so to speak.

...followed by a crash...

I'm sorry, I don't know what you mean by this, in that I don't know what crashes, or what you see. Does Linux, some part of KDE, your browser, or something else, "crash"? If it's something in Linux, looking at the system logs might be useful. I like KSystemLog for this, as it helps wade through the noise.

Anyway, the r8169 driver has had work since 18.04, it might work better in 20.04. Google finds chatter about various fixes to it; in particular one from April says there's a fix in kernel 5.4.32, and my Kubuntu 20.04 has 5.4.42. If you don't want to leave 18.04, I think there's a way to get later kernels on it, but I've no idea how advisable that is.

[megosdog]

Crash, as in data stops moving for a while. Or, at the very least the driver/card receives it, but nothing ever makes it past there to the applications. I ran tcpdump and it shows data flowing in like crazy, but during those brief periods of outage nothing seems to be making it to the application layer, and I'm not sure why.

[megosdog]

Okay, nevermind everyone. Laptop started having bad days, so I'm just gonna replace it, so we can consider this resolved.

[oshunluvr]

I was just gonna say sounds an awful lot like a hardware issue.

Get yourself a nice https://system76.com/laptops

[megosdog]

Yeah, I picked up a nice Lenovo refurb. I'd get a System76 laptop, but I can't afford that right now. Of course, they give us another stimulus check, and I might just throw that at a newer, better desktop. Then I can take my laptops out of rotation and just work with dual desktops.