Não é possível obter Ethernet da Universidade para funcionar com o Networkmanager

Question

Estou tentando conectar meu notebook Linux à porta ethernet da Oxford Brookes Uni, onde comecei a trabalhar. Acredito que o procedimento para laptops Windows aqui seria conectá-lo, ser redirecionado para um portal cativo e registrar seu endereço MAC.

Meu ThinkPad 13 não tem uma porta ethernet, portanto estou usando uma estação de encaixe "OneLink +" com ethernet (trabalhada em outras redes).

Infelizmente, o NetworkManager não se conecta a nada, apenas tenta várias vezes. Tudo está bem com Wi-Fi aqui (exceto para a conexão ser bastante fraca) ou com Ethernet em casa.

Esta é a saída de journalctl -u NetworkManager :

    Nov 01 13:31:28 burns NetworkManager[1149]: <info>  [1509543088.3349] policy: auto-activating connection 'Wired connection 1'
    Nov 01 13:31:28 burns NetworkManager[1149]: <info>  [1509543088.3396] device (eth0): Activation: starting connection 'Wired connection 1' (8c158a02-7bc0-3c71-bb0e-ef492c2e7992)
    Nov 01 13:31:28 burns NetworkManager[1149]: <info>  [1509543088.3414] device (eth0): state change: disconnected -> prepare (reason 'none', internal state 'managed')
    Nov 01 13:31:28 burns NetworkManager[1149]: <warn>  [1509543088.3427] device (eth0): set-link: unable to retrieve link negotiation
    Nov 01 13:31:28 burns NetworkManager[1149]: <info>  [1509543088.3510] device (eth0): set-hw-addr: set-cloned MAC address to 4A:4A:A2:36:09:06 (4A:4A:A2:36:09:06)
    Nov 01 13:31:28 burns NetworkManager[1149]: <info>  [1509543088.3574] device (eth0): state change: prepare -> config (reason 'none', internal state 'managed')
    Nov 01 13:31:28 burns NetworkManager[1149]: <info>  [1509543088.3608] device (eth0): state change: config -> ip-config (reason 'none', internal state 'managed')
    Nov 01 13:31:28 burns NetworkManager[1149]: <info>  [1509543088.3625] dhcp4 (eth0): activation: beginning transaction (timeout in 45 seconds)
    Nov 01 13:31:28 burns NetworkManager[1149]: <info>  [1509543088.3702] dhcp4 (eth0): dhclient started with pid 4659
    Nov 01 13:32:13 burns NetworkManager[1149]: <warn>  [1509543133.2582] dhcp4 (eth0): request timed out
    Nov 01 13:32:13 burns NetworkManager[1149]: <info>  [1509543133.2583] dhcp4 (eth0): state changed unknown -> timeout
    Nov 01 13:32:13 burns NetworkManager[1149]: <info>  [1509543133.2920] dhcp4 (eth0): canceled DHCP transaction, DHCP client pid 4659
    Nov 01 13:32:13 burns NetworkManager[1149]: <info>  [1509543133.2921] dhcp4 (eth0): state changed timeout -> done
    Nov 01 13:32:13 burns NetworkManager[1149]: <info>  [1509543133.2930] device (eth0): state change: ip-config -> failed (reason 'ip-config-unavailable', internal state 'managed')
    Nov 01 13:32:13 burns NetworkManager[1149]: <warn>  [1509543133.2949] device (eth0): Activation: failed for connection 'Wired connection 1'
    Nov 01 13:32:13 burns NetworkManager[1149]: <info>  [1509543133.2976] device (eth0): state change: failed -> disconnected (reason 'none', internal state 'managed')
    Nov 01 13:32:13 burns NetworkManager[1149]: <info>  [1509543133.3163] device (eth0): set-hw-addr: reset MAC address to 00:50:B6:80:8E:B5 (deactivate)

Após clonar o endereço MAC do laptop Windows que recebi da Uni, recebo essas mensagens de erro do diário Networkmanager:

Nov 01 18:21:57 burns NetworkManager[1013]: <info>  [1509560517.5929] manager: NetworkManager state is now CONNECTING
Nov 01 18:21:57 burns NetworkManager[1013]: <warn>  [1509560517.5949] device (eth0): set-link: unable to retrieve link negotiation
Nov 01 18:21:57 burns NetworkManager[1013]: <info>  [1509560517.6135] device (eth0): set-hw-addr: set-cloned MAC address to 4A:4A:A2:36:09:06 (4A:4A:A2:36:09:06)
Nov 01 18:21:57 burns NetworkManager[1013]: <info>  [1509560517.6209] device (eth0): state change: prepare -> config (reason 'none', internal state 'managed')
Nov 01 18:21:57 burns NetworkManager[1013]: <info>  [1509560517.6289] device (eth0): state change: config -> ip-config (reason 'none', internal state 'managed')
Nov 01 18:21:57 burns NetworkManager[1013]: <info>  [1509560517.6351] dhcp4 (eth0): activation: beginning transaction (timeout in 45 seconds)
Nov 01 18:21:57 burns NetworkManager[1013]: <info>  [1509560517.6659] dhcp4 (eth0): dhclient started with pid 4177

De dhclient -v , recebo o seguinte (Wifi desativado):

RTNETLINK answers: Operation not possible due to RF-kill
Listening on LPF/eth0/f8:16:54:ba:55:3a
Sending on   LPF/eth0/f8:16:54:ba:55:3a
Listening on LPF/enp0s31f6/a8:1e:84:85:95:39
Sending on   LPF/enp0s31f6/a8:1e:84:85:95:39
Listening on LPF/wlp3s0/14:ab:c5:01:af:1d
Sending on   LPF/wlp3s0/14:ab:c5:01:af:1d
Sending on   Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3 (xid=0x67ba8eaf)
DHCPDISCOVER on enp0s31f6 to 255.255.255.255 port 67 interval 5 (xid=0x1ce3ea9e)
DHCPREQUEST on wlp3s0 to 255.255.255.255 port 67 (xid=0x75c5dbab)
send_packet: Network is down
dhclient.c:2800: Failed to send 300 byte long packet over wlp3s0 interface.
receive_packet failed on wlp3s0: Network is down
receive_packet failed on eth0: Network is down
receive_packet failed on eth0: Network is down
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 7 (xid=0x67ba8eaf)
DHCPREQUEST on wlp3s0 to 255.255.255.255 port 67 (xid=0x75c5dbab)
send_packet: Network is down
dhclient.c:2800: Failed to send 300 byte long packet over wlp3s0 interface.
DHCPDISCOVER on enp0s31f6 to 255.255.255.255 port 67 interval 12 (xid=0x1ce3ea9e)
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 16 (xid=0x67ba8eaf)
DHCPDISCOVER on wlp3s0 to 255.255.255.255 port 67 interval 3 (xid=0x3941a37a)
send_packet: Network is down