After installing Ubuntu server 15.10, I am unable to reach the Internet and do not have an IPv4 address. ifconfig only shows lo, but if I type in ifconfig -a, it also shows enp1s0f0, which matches up to the internal ethernet port, but it doesn't have an IP address. I skipped around the steps in the installer, though I did auto-configure DHCP...

As far as I can tell, "enp1s0f0" seems to correspond to virtual machines, on CentOS/Red Hat, and I'm not sure why it's this instead of eth0...

I have tried renaming it to eth0 (fwiw), but a reboot wiped that out. I also tried adding auto-config code to /etc/network/interfaces, but no luck with that, either.

EDIT: Here's the interfaces file, more or less:

"# The loopback..."

auto lo

iface inet loopback

"# eth0"

auto enp1s0f0

iface enp1s0f0 inet dhcp

Also, I unplugged the Ethernet and plugged it into a Thunderbolt to Ethernet adapter, which Ubuntu recognizes, still no Internet... Plugged it back into internal Ethernet port, now Internet works. I don't know why. I'd still like to know about the enp1s0f0 interface, why it's not "en0" and how it's different.

  • Please edit your question to show your /etc/network/interfaces file.
    – chili555
    Dec 15 '15 at 15:36
  • Does sudo dhclient -4 -v enp1s0f0 allow you to get an IP address at all?
    – Thomas Ward
    Dec 15 '15 at 15:57
  • Also, Ubuntu now follows the Predictable Network Interface Naming standard, too. (Details on the standard, from freedesktop.org)
    – Thomas Ward
    Dec 15 '15 at 15:58
  • Ah gotcha, I figured it was a new thing in 15.10, I just didn't know what to search for (now I know PNIN is a thing!) Dec 15 '15 at 16:08
  • I am able to get an IP address now, I'm not sure why I wasn't before. Thanks for your assistance. Dec 15 '15 at 16:10

As Thomas W mentioned, the naming scheme (enp1s0f0) replaced the old one (en0) in 15.10 and it is not indicative of any issues.

I wish I knew exactly what I did to get an IP address (and therefore on the Internet), but I make those edits to the interfaces file (the part for "en0"), rebooted (still no luck), plugged in a Thunderbolt to Ethernet adapter (still no luck), plugged the ethernet cable back into the internal Ethernet port, had internet.

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