I am not sure if this is an appropriate place for this question, so please suggest an alternative and move if required...So I was trying to update a Bufallo Linkstation Pro v2 NAS from Debian Squeeze to Debian Lenny. I followed the Debian upgrade guide and everything seemed to work okay, except for an apt error with libav_tools, but that doesn't seem essential. I chose not to upgrade the kernel at this time (this was to be a later step). Now, this NAS has no display device and no serial connection. The only access to this machine is via SSH. So, all things looking good I restarted my machine. The boot seemed like it worked, the correct lights were flashing, but now I can't connect via SSH.The only way I have to access this NAS is by taking the disk out and inspecting it in another machine. Looking at the syslog etc, I can see that the machine is booting into Debian fine. However, something is up with the network. I manually edited the crontab to run the following diagnostics script:/sbin/ifconfigecho ---------------cat /etc/resolv.confecho -----------------cat /etc/hostsecho -----------------cat /etc/netconfigecho ----------------cat /etc/networksecho -----------------cat /etc/network/interfacesecho -----------------/usr/sbin/sshd -decho -----------------netstat -tulpnHere's the output of the script:    ---------------domain Homesearch Homenameserver 192.168.1.1-----------------127.0.0.1   localhost127.0.1.1   debian.Home debian# 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-----------------## The network configuration file. This file is currently only used in# conjunction with the TI-RPC code in the libtirpc library.## Entries consist of:##       <network_id> <semantics> <flags> <protofamily> <protoname> \#               <device> <nametoaddr_libs>## The <device> and <nametoaddr_libs> fields are always empty in this# implementation.#udp        tpi_clts      v     inet     udp     -       -tcp        tpi_cots_ord  v     inet     tcp     -       -udp6       tpi_clts      v     inet6    udp     -       -tcp6       tpi_cots_ord  v     inet6    tcp     -       -rawip      tpi_raw       -     inet      -      -       -local      tpi_cots_ord  -     loopback  -      -       -unix       tpi_cots_ord  -     loopback  -      -       -----------------default     0.0.0.0loopback    127.0.0.0link-local  169.254.0.0-----------------# This file describes the network interfaces available on your system# and how to activate them. For more information, see interfaces(5).# The loopback network interfaceauto loiface lo inet loopback# The primary network interface#allow-hotplug eth0#iface eth0 inet dhcpauto eth0iface eth0 inet static    address 192.168.1.150    netmask 255.255.255.0    gateway 192.168.1.1-----------------debug1: sshd version OpenSSH_5.5p1 Debian-6+squeeze5debug1: could not open key file '/etc/ssh/ssh_host_rsa_key': Permission deniedCould not load host key: /etc/ssh/ssh_host_rsa_keydebug1: could not open key file '/etc/ssh/ssh_host_dsa_key': Permission deniedCould not load host key: /etc/ssh/ssh_host_dsa_keydebug1: setgroups() failed: Operation not permitteddebug1: rexec_argv[0]='/usr/sbin/sshd'debug1: rexec_argv[1]='-d'Set /proc/self/oom_adj from 0 to -17socket: Address family not supported by protocoldebug1: Bind to port 22 on 0.0.0.0.Bind to port 22 on 0.0.0.0 failed: Permission denied.Cannot bind any address.-----------------(No info could be read for -p: geteuid()=1000 but you should be root.)Active Internet connections (only servers)Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program nametcp        0      0 127.0.0.1:3306          0.0.0.0:*               LISTEN      -               tcp        0      0 0.0.0.0:111             0.0.0.0:*               LISTEN      -               tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      -               tcp        0      0 0.0.0.0:60756           0.0.0.0:*               LISTEN      -               tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      -               tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN      -               udp        0      0 0.0.0.0:40009           0.0.0.0:*                           -               udp        0      0 0.0.0.0:111             0.0.0.0:*                           -               udp        0      0 0.0.0.0:764             0.0.0.0:*                           -               udp        0      0 127.0.0.1:161           0.0.0.0:*                           -               udp        0      0 0.0.0.0:39720           0.0.0.0:*                           -               udp        0      0 127.0.0.1:809           0.0.0.0:*                           -   Why questions are twofold:- Why does ifconfig not print any output?- What other information can I obtain via a cronjob that will help diagnose network issues and what other files can I look at without an interactive shell?        
How can I identify and fix network issues without an interactive or ssh login
debian;networking;ifconfig