Fixing Intel lan card problem

“Initializing Intel Boot Agent GE v.1.2.28 PXE-E05: LAN adapter’s configuration is corrupted or has not been initialized. The Boot Agent cannot continue.”

I340T4 (Intel® 82580)

Linux Printing

Linux applications –> PostScript doc –> PostScript printer

As most connected printers are not PostScript printer, hence:
Linux applications –> Ghostscript –> convert print job as PostScript format

Common Unix Printing System (CUPS)
print queue:     /var/spool/cups
lpr:                   For submitting print jobs
lpq:                  Checking print queue
lprm:               Removing Print jobs

Linux Locale

Linux uses Coordinated Universal Time (UTC) internally.
– when u save a file, the timestamp is stored in UTC

Translation between UTC and local time:
/etc/localtime   (non plain-text)

Path of timezone files:

To change the time zone:
1) get the timezone file from /usr/share/zoneinfo
2) copy or using soft link
ln -s /usr/share/zoneinfo/US/Eastern localtime

Debian:     /etc/timezone
Fedora:     /etc/sysconfig/clock

Temporarily changing the timezone:
$ export TZ=:/usr/share/zoneinfo/Europe/London

What is a Locale?
Locale is a way of specifying the computer’s language, country, and related information for purposes of customizing displays.

Listing Locale settings:
$ /usr/bin/local

Listing the available locale:
$ locale -a

Modifying Text-File Locales
iconv -f encoding [-t encoding] [inputfile] …
$ iconv -f iso-8859-1 -t UTF-8 umlautfile.txt > umlautfile-utf8.txt

Diagnosing Network Connections

Testing Basic Connectivity
$ ping -c 4 hostname

Tracing a Route
$ traceroute -n
(-n –> display target’s IP address rather than hostnames)

Checking Network Status
netstat –interface or -i                  Interface Information
netstat –route       or -r                 Routing Information
netstat –masquderade or -M       Masquerade Information
netstat –program  or -p                Program Use
netstat                                          Open Ports
netstat –all            or -a                All connections

Packet sniffer
tcpdump – intercept network packets and log them or display them on the screen
               – must run in root


Basic Networking Settings

Network Configuration:
Redhat:        /etc/sysconfig/network-scripts/ifcfg-name
Debian:        /etc/network/interfaces

Gateway Address:


To bring up a network interface:
ifconfig interface up addr netmask mask
# ifconfig eth0 up netmask

Setup the route:
# route add default gw

Configuring Routing:
Router = link 2 or more networks together, directing traffic between them on the basis of its routing table.

route {add | del} [-net | -host] target [netmask nm] [gw gw] [reject] [[dev] interface]
-net and -host:    force route to interpret the target as a network or computer address
netmask:             netmask setting
gw/gateway:        specify a router through which packets to the specified target should go
reject:                  blocking route, refuses all traffic destined for the specified network

# route add -net netmask gw
(Packets destined for the subnet should be passed through the router)

To enable the routing:
# echo “1” > /proc/sys/net/ipv4/ip_forward
/etc/sysctl.conf: net.ipv4.ip_forward = 1
/etc/sysconfig/sysctl (IP_FORWARD)

Bring the interface up/down:
# ifup eth0
# ifdown eth0

Configuring Hostnames:
# hostname
Many linux dist look in the /etc/hostname for a hostname to set a boot time.
Fedora: /etc/sysconfig/network

GPG – GNU Privacy Guard

What is it:
-Useful tool for encrypting email
-A private key and a public key
-Encrypt a msg with another user’s public key, which can be decrypted only with that user’s private key

To generate the key:
$ gpg –gen-key

Location of the key:

Export your public key: (Saves the public key associated with name in the file
$ gpg –export name >
(You can use your email address as name)

To email it:
Adding the –armor option produces ASCII output

To send your public key to a keyserver:
$ gpg –keyserver hostname –send-keys keyname
$ gpg –keyserver –send-keys
(This example sends the public key for from your public keyring to the server at

Importing Keys
To encrypt email you send to others, you must obtain their public keys.
$ gpg –import filename

Check the available keys:
$ gpg –list-keys

Revoking a key:
$ gpg –gen-revoke
——BEGIN PGP PUBLIC KEY BLOCK—–Version: GnuPG v2.0.19
(GNU/Linux)Comment: A revocation certificate should follow

Copy the above text into a file (eg revocation.gpg) and import the file to keyring:
$ gpg –import revocation.gpg

Pass the revocation to the GPG keyserver:
$ gpg –keyserver –send-keys

Encryt data
$ gpg –out encrypted-file –recipient uid –armor –encrypt original-file
(You can use UID from a gpg –list-keys, or just the email address portion)
(if omit the –armor option, resulting file is a binary file)
(–armor option turn the output as ASCII, so can cut and paste into email)

Decrypt data
$ gpg –out decrypted-file –decrypt encrypted-file

Signing Messages:
$ gpg –clearsign original-file
(Create a new file with the same name as the original, but with .gpg appended to the filename. The file is encrypted using your private key so that it may be decrypted only with your public key)

To verify the signature on a signed message:
$ gpg –verify received-file
(If any of the keys in your keyring can decode the message or verify the signature, gpg displays a Good signature message)