Networking issues with Haswell-based Linux increase Courvoisier consumption

[ewmayer]

Been running my Haswell system for ~2 weeks now, using thumb drive for file transfer, which is OK for transferring a Sandy-Bridge-suitable binary and doing preliminary perforance testing, but not for ongoing Haswell-specific [= AVX2] code-dev work. I was unable to find any Linux network drivers for the builtin networking on the MSI motherboard, so our very own Scott Bardwick kindly sent me an Intel network interface card [NIC] free of charge, and he and Mike/Xyzzy helped me in my efforts to get networking up and running - unsuccessfully, hence the thread. Here is a cull of the various e-mails we exchanged:

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o Here is the basic LAN topology [which Scott wrote up as an aid] I had running on the older Sandy Bridge-based system which previously occupied my ATX case [and which used the same Linux-install-on-SSD as I am still using]:

We have a macbook with WiFi and wired networking.
The MacBook WiFi appears to use 192.168.0.xxx network range.
The MacBook wired connection should be using 192.168.1.xxx range.

The Haswell box is wired only.
We want to wire the Haswell box to the Mac without a router, so an Ethernet cable is directly connecting the two.
The Haswell needs to be using 192.168.1.xxx to talk to the MacBook.

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o Intel Ethernet card install notes:

- After initial attempt to install card in pci1 slot led to no-joy, retried in pci3;
- 'lspci' shows hardware is recognized;
- 'lsmod' shows e1000e entry [= Intel NIC] as expected, but '0' in 'used by' column
- 'dmesg | grep eth0' shows the following ['renamed' entry same as 1st attempt, when card was plugged into pci1]:

	e1000e 0000:02:00.0: eth0: (PCI Express:2.5GB/s:Width x1) 00:1b:21:a8:53:44
	e1000e 0000:02:00.0: eth0: Intel(R) PRO/1000 Network Connection
	e1000e 0000:02:00.0: eth0: MAC: 3, PHY: 8, PBA No: E46981-005
	udev[572]: renamed network interface eth0 to eth2

As before [when card was in pci1], 'ifconfig' shows only an 8-line entry for 'loopback', no eth* stuff.

The last 'renamed' line especially is curious to me - I sense it's telling me something important, not sure what, though.

(Retrying 'dmesg | grep eth2' shows that the above line is the only one output by dmesg which refers to eth2).

Specifically, /etc/network/interfaces currently contains

allow-hotplug eth0
iface eth0 inet static

My thought was to maybe edit that to read 'eth2' - more on that below.

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At this point Mike suggested I download a Ubuntu image onto USB flash and try to boot from it, using its recipe to configure networking, but stopping short of anything that writes to the current hard disk. I have burned a Ubuntu boot flash and tested whether the BIOS can see that, but have not yet made the above experiment.

Rather, after changing eth0 to eth2 in my /etc/network/interfaces file, I simply booted into Debian as normal to test out that change ... and 'ifconfig' now shows the eth2 stuff above the loopback entries:

eth2	Link encap:Ethernet   HWAddr 00:1b:21:a8:53:44
		inet addr:192.168.1.102	Bcast:192.168.1.255	Mask:255.255.255.0
		UP BROADCAST MULTICAST	MTU:1500	Metric:1
		RX packets:0 errors:0 dropped:0 overruns:0 frame:0
		TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
		collisions:0 txqueuelen:1000
		RX bytes:0 (0.0 B)	TX bytes:0 (0.0 B)
		Interrupt:16	Memory:f7cc0000-f7ce0000

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:16436	Metric:1
		RX packets:8 errors:0 dropped:0 overruns:0 frame:0
		TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
		collisions:0 txqueuelen:0
		RX bytes:560 (560.0 B)	TX bytes:560 (560.0 B)

Still can't ssh to it from the macbook, though. [And yes, I checked that the ethernet cable was plugged in, and into the proper slots - on the Haswell side that means the NIC card, not the ethernet port built into the motherboard. :-]

Any help from the Linux/networking gurus is appreciated!

[paulunderwood]

Can you "ping 192.168.1.102" from the Haswell box?

Not sure about this, but you could try changing the netmask to 255.255.0.0

( My loopback is inet addr:127.0.0.1 Mask:255.0.0.0 )

[ewmayer]

Hi, Paul:

Originally Posted by paulunderwood

Can you "ping 192.168.1.102" from the Haswell box?

Yes.

Not sure about this, but you could try changing the netmask to 255.255.0.0

Would I have to manually restart networking after editing the /etc/network/interfaces file thusly?

[paulunderwood]

Not sure, but "ifdown eth2", "ifup eth2" might help.

Check out your loopback; I am pretty sure it should be 127.0.0.1

My /etc/network/interfaces:

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
allow-hotplug eth0
#NetworkManager#iface eth0 inet dhcp

Maybe yours should say "eth2"

"/etc/init.d/networking restart" won't do any harm

[paulunderwood]

Can you "ssh 192.168.1.102" from the Haswell? This will tell you sshd is installed and running.

[ewmayer]

Originally Posted by paulunderwood

Not sure, but "ifdown eth2", "ifup eth2" might help.

'ifup' gives 'interface eth2 already configured'

Check out your loopback; I am pretty sure it should be 127.0.0.1

Whoops - I mis-copied that one ... it is indeed 127.0.0.1 according to ifconfig. [OP edited accordingly]

My /etc/network/interfaces:

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
allow-hotplug eth0
#NetworkManager#iface eth0 inet dhcp

Maybe yours should say "eth2"

Both the 'hotplug' and 'iface ... static' entries in my interface file use 'eth2'.

Originally Posted by paulunderwood

Can you "ssh 192.168.1.102" from the Haswell? This will tell you sshd is installed and running.

Yep - after the obligatory first-ssh-attempt 'authenticity if host [blah] can't be established' warning, I am able to login to myself successfully, or something.

"/etc/init.d/networking restart" won't do any harm

OK, just did that - ping/ssh-to-self still OK, connect-from-outside still no-go.

One thing I notice - during all the above, I saw none of the LEDs on the port of the NIC flash ... tried unplug/replug cable, nothing. But presumably the card is active, otherwise none of the above stuff would work, right?

Since the loopback stuff if OK [typo by me in my OP being the only bug], is the next-thing-to-try changing the netmask as you suggested?

[paulunderwood]

Originally Posted by ewmayer

One thing I notice - during all the above, I saw none of the LEDs on the port of the NIC flash ... tried unplug/replug cable, nothing. But presumably the card is active, otherwise none of the above stuff would work, right?

Since the loopback stuff if OK [typo by me in my OP being the only bug], is the next-thing-to-try changing the netmask as you suggested?

Hmm my NIC sockets light up when I plug in a cable.

Yeah, the subnet mask trick might work, but is a bit perplexing if the wired socket of the MacBook is on 192.168.1.xxx.

[Xyzzy]

To restart networking, as root type:

/etc/init.d/networking restart

[ewmayer]

Originally Posted by Xyzzy

To restart networking, as root type:

/etc/init.d/networking restart

Yeah - Paul already suggested that ... but just restarted for the 2nd time, after editing netmask to 255.255.0.0 in the interfaces file. Self-ping again works, no joy from outside.

Gotta get some actual algo work done ... let's sleep on it, thanks for the suggestions!

[paulunderwood]

I guess you would have to change the netmask on the MacBook too.

Make sure the cable works too.

[ewmayer]

Originally Posted by paulunderwood

I guess you would have to change the netmask on the MacBook too.

Make sure the cable works too.

While trying the first, I noticed a 'cable unplugged' note in the mac's network-setup dialog ... that led me to discover the lack-of-LED cause, which is that the NIC's cable connector is bad - I have to manually jam the cable plug into the connector hard for the LEDs to come on and the above dialog's physical-connection-status message to change to the desired 'connected'.

[I say the NIC connector because the same cable worked just fine with the old mobo ... let's just say 'connection to the outside world is dodgy'.]

Anyhoo, even with one hand jamming the cable in while the other types 'shh...' ... no joy. Also reverted the netmasks on both sides to the previous values of 255.255.255.0 and retried (again keeping one eye on the connected-or-not status line in the macbook's dialog to make sure it read 'connected') - still nothing. Bloody hell.

BTW, I still have no idea what that 'rename eth0 to eth2' business is all about - can anyone explain why the old-setup eth0 wasn't OK?