Problem connecting with wired connection

[viet.le175]

Once again here's another problem my linux decided to break down.


My wifi is working but when it comes to being wired in...not so much.


I tried a lot of solutions but none worked...


It was working this morning and now it is not.


Heres a list of stuff. Why am I not connecting to my wired connection?


ifconfig



eth0 Link encap:Ethernet HWaddr 80:fa:5b:2b:96:84
inet6 addr: fe80::82fa:5bff:fe2b:9684/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:73 errors:0 dropped:0 overruns:0 frame:0
TX packets:124 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:6555 (6.5 KB) TX bytes:25744 (25.7 KB)

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:833 errors:0 dropped:0 overruns:0 frame:0
TX packets:833 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:79645 (79.6 KB) TX bytes:79645 (79.6 KB)

wlan0 Link encap:Ethernet HWaddr a4:34:d9:64:d9:a8
inet addr:192.168.2.36 Bcast:192.168.3.255 Mask:255.255.252.0
inet6 addr: fe80::a634:d9ff:fe64:d9a8/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1816 errors:0 dropped:0 overruns:0 frame:0
TX packets:1529 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1526261 (1.5 MB) TX bytes:293164 (293.1 KB)


/etc/NetworkManager/NetworkManager.conf



[main]


plugins=ifupdown,keyfile,ofono
dns=dnsmasq

[ifupdown]
managed=true


/etc/network/interfaces


# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback




nm-tool



- Device: wlan0 [staybridge] --------------------------------------------------
Type: 802.11 WiFi
Driver: iwlwifi
State: connected
Default: yes
HW Address: A4:34:D9:64:D9:A8

Capabilities:
Speed: 1 Mb/s

Wireless Properties
WEP Encryption: yes
WPA Encryption: yes
WPA2 Encryption: yes

Wireless Access Points (* = current AP)
PC2: Infra, C8:D7:19:48:70:C0, Freq 2422 MHz, Rate 54 Mb/s, Strength 40 WPA2
staybridge: Infra, 00:02:6F:CB:F5:60, Freq 2412 MHz, Rate 54 Mb/s, Strength 72
staybridge: Infra, 00:02:6F:BF:2C:70, Freq 2417 MHz, Rate 54 Mb/s, Strength 60
staybridge: Infra, 00:02:6F:BF:2C:84, Freq 2442 MHz, Rate 54 Mb/s, Strength 54
CableWiFi: Infra, 50:1C:BF:49:7B:2C, Freq 5805 MHz, Rate 54 Mb/s, Strength 35
staybridge: Infra, 00:02:6F:B7:31:F8, Freq 2427 MHz, Rate 54 Mb/s, Strength 40
staybridge: Infra, 00:02:6F:B7:32:00, Freq 2447 MHz, Rate 54 Mb/s, Strength 35
EnGeniusBF2C78: Infra, 00:02:6F:BF:2C:78, Freq 2462 MHz, Rate 54 Mb/s, Strength 56
PC: Infra, C4:3D:C7:8E:82:88, Freq 2437 MHz, Rate 54 Mb/s, Strength 47 WPA2
PC2: Infra, C8:D7:19:48:70:C1, Freq 5180 MHz, Rate 54 Mb/s, Strength 35 WPA2
staybridge: Infra, 00:02:6F:E9:DB:C0, Freq 2462 MHz, Rate 54 Mb/s, Strength 62
staybridge: Infra, 00:02:6F:BF:2C:60, Freq 2432 MHz, Rate 54 Mb/s, Strength 49
xfinitywifi: Infra, 50:1C:BF:49:7B:2E, Freq 5805 MHz, Rate 54 Mb/s, Strength 35
staybridge: Infra, 00:02:6F:B7:32:04, Freq 2447 MHz, Rate 54 Mb/s, Strength 35
CableWiFi: Infra, 18:9C:5D:8E:9C:83, Freq 2462 MHz, Rate 54 Mb/s, Strength 35
*staybridge: Infra, 00:02:6F:E9:DB:B0, Freq 2462 MHz, Rate 54 Mb/s, Strength 69
VAIO-UD56UU: Infra, D0:AE:EC:A9:A4:8A, Freq 2457 MHz, Rate 54 Mb/s, Strength 37 WPA WPA2
optimumwifi: Infra, 50:1C:BF:49:7B:20, Freq 2412 MHz, Rate 54 Mb/s, Strength 37
optimumwifi: Infra, F0:29:29:C3:4A:60, Freq 2462 MHz, Rate 54 Mb/s, Strength 35
TWCWiFi: Infra, 50:1C:BF:49:7B:22, Freq 2412 MHz, Rate 54 Mb/s, Strength 39
xfinitywifi: Infra, D0:C7:89:3B:B8:A1, Freq 2437 MHz, Rate 54 Mb/s, Strength 35

IPv4 Settings:
Address: 192.168.2.36
Prefix: 22 (255.255.252.0)
Gateway: 192.168.3.251

DNS: 8.8.8.8
DNS: 8.8.4.4


- Device: eth0 -----------------------------------------------------------------
Type: Wired
Driver: r8169
State: disconnected
Default: no
HW Address: 80:FA:5B:2B:96:84

Capabilities:
Carrier Detect: yes
Speed: 1000 Mb/s

Wired Properties
Carrier: on


sudo lshw -C network



*-network
description: Ethernet interface
product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0.1
bus info: pci@0000:01:00.1
logical name: eth0
version: 12
serial: 80:fa:5b:2b:96:84
size: 1Gbit/s
capacity: 1Gbit/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 1000bt 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=rtl8411-2_0.0.1 07/08/13 latency=0 link=yes multicast=yes port=MII speed=1Gbit/s
resources: irq:126 ioport:e000(size=256) memory:df214000-df214fff memory:df210000-df213fff
*-network
description: Wireless interface
product: Wireless 8260
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:02:00.0
logical name: wlan0
version: 3a
serial: a4:34:d9:64:d9:a8
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=iwlwifi driverversion=4.2.0-42-generic firmware=25.30.13.0 ip=192.168.2.36 latency=0 link=yes multicast=yes wireless=IEEE 802.11abgn
resources: irq:129 memory:df100000-df101fff


UPDATE


I tried adding these lines of codes inside /etc/network/interfaces and no changes



auto eth0
iface eth0 inet dhcp

[grahammechanical]

UP BROADCAST RUNNING MULTICAST

says that the ethernet adapter is powered up and is working as far as Ubuntu is concerned. Disable networking and RUNNING will disappear from the printout. But nm-tool says disconnected. What version of Ubuntu are you using?

I would not put anything in the /etc/network/interfaces file as that is known to interfere with Network Manager. This is all that should be in the interfaces file as far as I can tell.


graham@Ub1604:~$ cat /etc/network/interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback


And it has been this way ever since Ubuntu started using Network Manager. If the wired connection is intermittent then perhaps there is a fault in the cable or the connections of the cable are not securely attached.

Regards

[JKyleOKC]

I had an almost-identical problem last week that turned out to be a misconfigured default gateway setting. I never could find out what changed it. However setting the default gateway back to the correct values cured it. My machine has two network cards and Network Manager was setting the gateway values using the wrong one. This is not likely to be the exact cause of your problem, but posting the output of "sudo route" may give others ideas as to why your wired interface is failing to obtain an IP address!