07 February 2012

59. Some problems with a headless box with four ethernet cards

I'll put this here more as general information rather than a solution to anything.

The situation:
I got my hands on a tiny WAN server with four ethernet cards (Intel Pro 100). Two of the ports light up when attaching CAT5 cables (eth3 and eth4), two of them remain dead (eth0 and eth1).

I thought I was clever:


auto eth0
iface eth0 inet static
auto eth1
iface eth1 inet static
auto eth2
iface eth2 inet static
auto eth3
iface eth3 inet static

/etc/hosts localhost garfish salmon wallaby kookaburra beryllium boron tantalum
# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

Well, here's what happened:
I installed Debian Stable on the HDD using virtualbox -- it's a tried an tested method by which instead of creating a virtual HD you attach an external HD via USB and pass it through to a new virtualbox instance which only has a CD or DVD image of a Debian installation medium mounted. I might explain this in more detail in a separate post.

Anyway, installation was fine. I installed the basic tools, ssh-server, file-server etc., but no desktop environment.

I knew that I had to manually set the IP address since the server would be attached to a switch, not a router, so I attached the HDD as an external USB HDD to a tower with a display attached to it, hit F9 during boot to boot from the external harddrive, and things looked ok. Well, the network card hadn't been brought up  -- I guess this is normally done by network-manager even if you don't configure your /etc/network/interfaces

sudo ifconfig eth0 netmask up

was enough to get me connected, after which I edited the /etc/apt/sources.list, upgraded to testing, and installed a few network tools and a collecting of non-free drivers for good luck.

I edited the /etc/hosts and /etc/network/interfaces as shown above

What I saw (using tshark -i eth1 on another box on the same local network):
23.630357 -> DNS 69 Standard query AAAA
 23.631220 -> DNS 144 Standard query
response, No such name

Anyway, odd, but let's leave it at that.

I put the HDD in the server, then tried to log in via ssh. Nothing. And no response to pinging. Can't reach the apache server running.

Hmm...pulled out the hdd put a crontab script to run once every minute which would run lspci, ip addr and ping back to one of my boxes. Put the hdd back in, started and listened with tshark. Well, the server was pinging away, but I couldn't ping back, nor ssh in, nor connect to port 80.

Looking at the ip addr output:
2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN qlen 1000
    link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff
    inet brd scope global eth0
3: eth1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN qlen 1000
    link/etherxx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff
    inet brd scope global eth1
4: eth2: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN qlen 1000
    link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff
    inet brd scope global eth2
5: eth3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff
    inet brd scope global eth3
    inet6 fe80::20e:b6ff:fe2a:a830/64 scope link
       valid_lft forever preferred_lft forever

Not too shabby looking - eth0 and eth1 are down, but at least the server isn't turning green and projectile vomiting.

But /var/mail/me:
Date: Mon, 06 Feb 2012 17:28:04 +1100
PING ( 56(84) bytes of data.
>From icmp_seq=1 Destination Host Unreachable
Odd, since I could SEE the pings using wireshark/tshark - but from

Anyway, to make a very long story short -- the solution was to remove eth0 and eth1 from /etc/network/interfaces -- they are dead, and initialising them were causing odd behaviour.

There isn't much of a moral to this story, and the usefulness to other people is perhaps limited, but just in case you do recognise the situation, try limiting yourself to good ethernet ports, then take it from there...

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