The C function getsockopt lets you get the error codes with the option SO_ERROR . The possible error numbers are defined in the global errno.h . The relevant values are: #define ETIMEDOUT 110 /* Connection timed out */ ... But here's the whole list on my Linux system ( /usr/include/asm-generic/errno.h ): #ifndef _ASM_GENERIC_ERRNO_H #define _ASM_GENER...

Use the read command to pause a shell script and give the user a chance to stop it: #!/bin/sh echo "Press CTRL-C to stop this scrip...

This procedure sets up an IPSec vpn server on Linux with Preshared Key (PSK) using Openswan . Install Openswan: # yum install openswan Edit /etc/ipsec.conf . This is about the minimum needed to run IPSec server. Instead of running L2TP on port 1701, I'm running TCP on port 8080 so that I can test the setup with nc later. # /etc/ipsec.conf - Openswan IPsec configurati... Edit /etc/ipsec.secrets . # # Preshared key for clients connecting from a... Start IPSec: # /etc/init.d/ipsec start Check status: # ipsec auto --status Monitor IPSec log: # less /var/log/secure If IPSec is running KLIPS, you should see a new nic ( ipsec0 ). There's no ipsec0 if IPSec is running NETKEY. # ifconfig eth0 Link encap:Ethernet HWadd...

These steps set up a Linux host as IPSec client, using Openswan . Install Openswan: # yum install openswan Edit /etc/ipsec.conf . Instead of L2TP on port 1701, I'm setting up TCP on port 8080 so that I can test the connection with nc . # /etc/ipsec.conf - Openswan IPsec configuration f... Edit /etc/ipsec.secrets . # include /etc/ipsec.d/*.secrets 192.168.0.101 ... Start IPSec: # /etc/init.d/ipsec start Connect to IPSec server: # ipsec auto --up TCP8080-PSK-CLIENT 104 "TCP80...

This is a step-by-step guide: How to setup pptp vpn server on linux (fedora 14) It looks like that the only PPTP server on Linux that had any influence was Poptop , which was last updated in 2007. There doesn't seem to be much interest in keeping pptpd up-to-date on Linux, and the reason could be that PPTP itself isn't much secure. From Wikiperia : PPTP has been the subject of many security analyses and serious security vulnerabilities have been found in the protocol. The known vulnerabilities relate to the underlying PPP authentication protocols used, the design of the MPPE protocol as well as the integration between MPPE and PPP authentication for session key establishment. In fact, the maintainers of PPTP Client and Poptop recommend...

Goto http://www.adobe.com/downloads/ , click the download flash player icon Select YUM for Linux from "Select version to download" dropdown Save the rpm file, which is about 4.3K. Install the RPM: rpm -i adobe-release-i386-1.0-1.noarch.rpm Import the Adobe key: rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-adobe-li... Install the flash plugin yum install flash-plugin nspluginwrapper.x86_64 ns...

According to SELinux Trouble Shooting Tool AVC AVC stands for Access Vector Cache . SELinux Denials are reported in the logging system as AVC 's with the denied key word.

Start: [root@belo ~]# service sshd start Generating SS... Stop: [root@belo ~]# service sshd stop Stopping sshd:... Or: [root@belo ~]# /etc/init.d/sshd start Starting ... Start sshd on boot: [root@belo ~]# chkconfig sshd on

rdesktop is the Linux equivalent of mstsc on Widnows. To install rdesktop on Fedora, enter: yum install rdesktop To start rdesktop in full screen mode: rdesktop -f remote_host_name To toggle full screen mode, use key combination: Ctrl+Alt+Enter.

If you want to add security to your wireless network, you almost never want to use WEP . WPA is an improved encryption algorithm that avoids many of the WEP vulnerabilities. However, FC4 (Fedora Core) doesn't support WPA out of the box. I have to install wpa_supplicant in order to access my wireless AP with WPA encryption. Since my Airlink wireless card only shipped with Windows drivers, I also needed ndiswrapper to make it work under Linux. This is my experience setting up wpa_supplicant with ndiswrapper. 1. Download wpa_supplicant 0.5.8 from http://hostap.epitest.fi/wpa_supplicant/ . Extract files to a working directory. 2. Create a .config file that contains: CONFIG_DRIVER_NDISWRAPPER=y CONFIG_CTRL_IFACE=y The first line initially read CONFIG_DRIVER_WEXT=y following the ndiswrapper documentation, but that didn't work for me. 3....