Wi-Fi 无法在 Ubuntu 17.10 上运行

在我更改路由器的名称和密码之前，我能够在我的 Ubuntu 17.10 上使用 Wi-Fi。从那以后，我一直无法使用互联网。我的网络管理员甚至没有显示可用设备。我尝试了 Askubuntu 上链接中的所有步骤：如何在终端中手动连接和断开网络？

这是我尝试使用该wpa_supplicant方法时得到的结果：

skywalker@lancelot ~ % sudo wpa_supplicant -iwlp2s0 -c/etc/wpa_supplicant/wpa_supplicant.conf -Dnl80211
Successfully initialized wpa_supplicant
wlp2s0: SME: Trying to authenticate with 7a:ff:ca:3a:30:ff (SSID='lancelot' freq=2462 MHz)
wlp2s0: Trying to associate with 7a:ff:ca:3a:30:ff (SSID='lancelot' freq=2462 MHz)
wlp2s0: Associated with 7a:ff:ca:3a:30:ff
wlp2s0: CTRL-EVENT-DISCONNECTED bssid=7a:ff:ca:3a:30:ff reason=3 locally_generated=1
wlp2s0: CTRL-EVENT-REGDOM-CHANGE init=CORE type=WORLD
wlp2s0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
wlp2s0: SME: Trying to authenticate with 7a:ff:ca:3a:30:ff (SSID='lancelot' freq=2462 MHz)
wlp2s0: Trying to associate with 7a:ff:ca:3a:30:ff (SSID='lancelot' freq=2462 MHz)
wlp2s0: Associated with 7a:ff:ca:3a:30:ff
wlp2s0: CTRL-EVENT-DISCONNECTED bssid=7a:ff:ca:3a:30:ff reason=3 locally_generated=1
wlp2s0: CTRL-EVENT-REGDOM-CHANGE init=CORE type=WORLD

这里有更多细节

skywalker@lancelot ~ % lspci -knn |grep Net -A2
00:19.0 Ethernet controller [0200]: Intel Corporation 82579LM Gigabit Network Connection
[8086:1502] (rev 04)
    Subsystem: Dell 82579LM Gigabit Network Connection (Lewisville) [1028:0493]
    Kernel driver in use: e1000e
    Kernel modules: e1000e
--
02:00.0 Network controller [0280]: Intel Corporation Centrino Ultimate-N 6300 [8086:422b] (rev 35)
    Subsystem: Intel Corporation Centrino Ultimate-N 6300 3x3 AGN [8086:1121]
    Kernel driver in use: iwlwifi
skywalker@lancelot ~ % uname -a                        
Linux lancelot 4.13.0-21-generic #24-Ubuntu SMP Mon Dec 18 17:29:16 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
skywalker@lancelot ~ % rfkill list       
0: phy0: Wireless LAN
    Soft blocked: no
    Hard blocked: no
1: dell-wifi: Wireless LAN
    Soft blocked: no
    Hard blocked: no
skywalker@lancelot ~ %

我的问题是， 如何设置我的 Wi-Fi 以能够连接到任何路由器并使用互联网？