也是更新后出现的问题，一个月前的问题一直拖到现在，早发现早解决。
问题描述
桌面右上角企鹅图标右侧图标显示为空边框扇形，如图所示：
尝试解决
尝试一：
首先重启交换机，然后重启电脑，多试几次总会成功检测到。具体原因不记得了，跟某些协议有什么关系，但是谁遭得住每次联网都这么整几次啊。
成功解决
分析原因，然后针对问题进行解决，第一种半吊子的方法不建议采用，还是得仔细思考。
网卡驱动出现了问题，找到与网卡对应的最新驱动进行安装。
查看网卡型号
输入lspci -k | grep -i -A2 net
网卡型号为Ethernet controller: Marvell Technology Group Ltd. 88E8042 PCI-E Fast Ethernet Controller (rev 10)
下载最新相应的网卡驱动，并查看相关文档说明
1.Preparing the Driver Installation Package
Before the sk98lin driver installation script can be invoked, the
installation package needs to be unpacked:
Login as ‘root’.
To unpack the driver installation package, execute the command
tar xfvj install_A.B.C.D.tar.bz2
or
bunzip2 -c install_A.B.C.D.tar.bz2 | tar xfv -
2.Driver Installation
After the driver installation package is unpacked, execute the following commands to start the sk98lin driver build process:
cd DriverInstall
./install.sh
Select the driver installation mode (see following sections).
NOTE: In case you have installed another driver module than the original
Marvell driver you will be asked how to further proceed. You can
ignore the fact, you can rename the other driver, or you can erase
the driver. We recommend to erase the driver to avoid unwanted
side effects and interdependencies.
Wait for the driver build process to finish.
Depending on the installation mode you selected, the driver is either
compiled and installed, or a kernel patch is generated.
NOTE:
Depending on your Linux distribution, the name of your device may have
changed after successful installation. In order to restore your old
device, start the appropriate network configuration utility and rename
the device.
3.Installation Mode
When selecting the installation mode, the driver sources shipped
with the install package are compiled and the resulting driver
module object file is installed to a suitable location (usually somewhere
below directory /lib/modules/…).
No source files of the driver are installed into a kernel directory.
Only the driver module object file and the man page of the driver are
installed onto your system permanently.
Installation mode means that the build process runs automatically
without any user interaction. In case of installation problems,
the driver installation script autonomously tries to solve the problem
(if possible).
After the compilation has finished, the initial system state and
configuration is recovered and all (possibly) backed-up system
files are restored from the initial configuration.
出现的问题：
“./install.sh 42: ./functions: Syntax error: “(” unexpected”
错误原因：文件格式不是unix格式，脚本文件是在windows系统中编写的
解决：
:set fileformat=unix
bash -x install.sh
重启电脑，成功检测
