dhclient: receive_packet перестал работать на wlan2: Сеть снижается

Время от времени мои сбои соединения Wi-Fi. В syslog Я определяю следующие сообщения об ошибках:

May 10 17:03:35 lati dhclient: receive_packet failed on wlan2: Network is down
May 10 17:03:35 lati wpa_supplicant[24883]: wlan2: Reject scan trigger since one is already pending
May 10 17:03:35 lati wpa_supplicant[24883]: wlan2: Failed to initiate AP scan
May 10 17:03:35 lati dhclient: send_packet: Network is unreachable
May 10 17:03:35 lati dhclient: dhclient.c:2413: Failed to send 300 byte long packet over fallback interface.
May 10 17:03:35 lati kernel: [11822.411877] e1000e: eth2 NIC Link is Down
May 10 17:03:36 lati NetworkManager[793]: <info> (wlan2): supplicant interface state: scanning -> disabled
May 10 17:03:36 lati NetworkManager[793]: <info> wpa_supplicant stopped
May 10 17:03:36 lati NetworkManager[793]: <info> (wlan2): supplicant interface state: disabled -> down
May 10 17:03:36 lati NetworkManager[793]: <info> (wlan2): device state change: activated -> unavailable (reason 'supplicant-failed') [100 20 10]
May 10 17:03:36 lati NetworkManager[793]: <info> (wlan2): deactivating device (reason 'supplicant-failed') [10]

Требуются еще 20-30 секунд, и это снова соединяется.

Что-либо подозрительное там? Что-нибудь я могу сделать для улучшения ситуации?

Информация о системе:

• Ubuntu 14.04.5 LTS (надежный человек)
• Архитектура: 64 бита
• Версия ядра: 4.4.0-72-универсальный
• Dell E7440
• Версия BIOS: A14

Мой сетевой контроллер:

02:00.0 Network controller: Intel Corporation Wireless 7260 (rev 73)
        Subsystem: Intel Corporation Dual Band Wireless-AC 7260
        Flags: bus master, fast devsel, latency 0, IRQ 47
        Memory at f7d00000 (64-bit, non-prefetchable) [size=8K]
        Capabilities: [c8] Power Management version 3
        Capabilities: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+
        Capabilities: [40] Express Endpoint, MSI 00
        Capabilities: [100] Advanced Error Reporting
        Capabilities: [140] Device Serial Number f8-16-54-ff-ff-0c-6d-31
        Capabilities: [14c] Latency Tolerance Reporting
        Capabilities: [154] Vendor Specific Information: ID=cafe Rev=1 Len=014 <?>
        Kernel driver in use: iwlwifi

Мой беспроводной интерфейс:

  *-network
       description: Wireless interface
       product: Wireless 7260
       vendor: Intel Corporation
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: wlan2
       version: 73
       serial: f8:16:54:0c:6d:31
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=iwlwifi driverversion=4.4.0-72-generic firmware=17.352738.0 ip=192.168.1.2 latency=0 link=yes multicast=yes wireless=IEEE 802.11abgn
       resources: irq:47 memory:f7d00000-f7d01fff

Ошибки от dmesg | grep -i firmware:

[    0.124074] [Firmware Bug]: ACPI: BIOS _OSI(Linux) query ignored
[    2.134682] iwlwifi 0000:02:00.0: loaded firmware version 17.352738.0 op_mode iwlmvm
[   68.377255] Bluetooth: hci0: Intel Bluetooth firmware file: intel/ibt-hw-37.7.10-fw-1.80.2.3.d.bseq
[   68.596005] Bluetooth: hci0: Intel Bluetooth firmware patch completed and activated