I have a dual-boot of Ubuntu 14.10 and Windows 10.
No networking issues are present after booting to Windows.
Whenever I boot into Ubuntu, however, I cannot connect even to my router (ZTE ZXDSL 931VII). DHCP seems not to grab an IP (I never get an ipv4 address and ipv6 only gets the MAC-based autoconfigured one), although tcpdump does list some (I assume outgoing) ARP and other UDP packets.
Previously the wired connection was working, however since I didn't boot for a few months, I'm not sure when this issue started. I assume it's probably due to some updates. :-/
Wireless connection, btw, does work without any extra configuration.
I've tried several things which did not fix the problem (top to bottom):
- ifconfig eth0 up and down
- Configuring DNS servers to 22.214.171.124 and 126.96.36.199
- Reconfiguring DHCP (dhclient.conf)
- Specifying variations of auto eth0 and iface eth0 inet dhcp in /etc/network/interfaces (ended up rendering the eth0 iface unmanaged)
- Changing my hostname
- Manually setting up a static ipv4 address
- Disabling ipv4, enabling ipv6 and vice versa
- Removing docker interfaces
- Various other settings through the network manager GUI
In short, everything looks normal from the configuration standpoint and I feel that I've pretty much exhausted my attempts to repair this.
As I see it, no IP connectivity is achieved whatsoever. I didn't bother probing the router via MAC.
I also didn't try updating drivers or any related software, but I will post back here once I do.
This is my network card:
05:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 06) Subsystem: Gigabyte Technology Co., Ltd Motherboard Flags: bus master, fast devsel, latency 0, IRQ 74 I/O ports at b000 [size=256] Memory at fe600000 (64-bit, non-prefetchable) [size=4K] Memory at d0000000 (64-bit, prefetchable) [size=16K] Capabilities:  Power Management version 3 Capabilities:  MSI: Enable+ Count=1/1 Maskable- 64bit+ Capabilities:  Express Endpoint, MSI 01 Capabilities: [b0] MSI-X: Enable- Count=4 Masked- Capabilities: [d0] Vital Product Data Capabilities:  Advanced Error Reporting Capabilities:  Virtual Channel Capabilities:  Device Serial Number 01-00-00-00-68-4c-e0-00 Kernel driver in use: r8169
ifconfig gives me:
eth0 Link encap:Ethernet HWaddr 74:d4:35:xx:yy:zz inet6 addr: fe80::76d4:35ff:fexx:yyzz/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:1440 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
When I check the state of the network card, it shows link detected.
$ ethtool eth0 Settings for eth0: Supported ports: [ TP MII ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Half 1000baseT/Full Supported pause frame use: No Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Half 1000baseT/Full Advertised pause frame use: Symmetric Receive-only Advertised auto-negotiation: Yes Link partner advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full Link partner advertised pause frame use: Symmetric Link partner advertised auto-negotiation: Yes Speed: 100Mb/s Duplex: Full Port: MII PHYAD: 0 Transceiver: internal Auto-negotiation: on Supports Wake-on: pumbg Wake-on: g Current message level: 0x00000033 (51) drv probe ifdown ifup Link detected: yes