El conocimiento al alcance de todos.

Thanks to:  http://www.howfantastic.net/ Network Diagram Premise A branch office with an ADSL connection would like to access corporate and local resources without running a local client on office machines. Split tunnelling is not required, all traffic must be routed back up to the corporate HQ. Only one static IP has been provided by the ADSL ISP. Config We’ll need to port forward UDP 500 (IKE) so that our corporate ASA can connect to the branch ASA. On the ADSL router we use the following NAT rules: ip nat inside source list LAN interface FastEthernet0/0 overload ip nat inside source static udp 192.168.1.1 500 interface FastEthernet0/0 500 You’ll see I’ve moved the B-End IP of the IPSec tunnel to the ADSL router so the A-End config doesn’t change. All I need to do is renumber the blue linknet to my chosen RFC1918 subnet of 192.168.1.0/24 and give my ASA a new default route matching the ADSL routers interface and all is well. Testing One thing which has bitten ...

Thanks to: http://blogs.msdn.com/b/ajay_pathak/ Recently I came across a very strange problem. A website developed using Visual Studio 2010. While debugging everything works perfectly fine while using Visual Studio development server. All the images and CSS are applied to website as it was expected. However when I deployed this website on IIS, the CSS and Image files are not showing on website. . After doing some research, I get to know that static content handler is missing in IIS. To display static content, I just added static file module. And the website is now showing CSS and images.

Gracias a: https://voidtech.wordpress.com/ Problema En mi distribución debian 6 (squeeze), al agregar un script de iptables para que se ejecutara al arrancar la maquina ejecute lo que antaño siempre hacia, pero que esta véz me daría una sorpresa: root@host:/etc/init.d# update-rc.d firewall defaults 80 update-rc.d: using dependency based boot sequencing insserv: warning: script 'firewall2' missing LSB tags and overrides Leyendo un poco, parece que a partir de la versión 6.0 de la distribución debian se utilizá otro sistema de arranque de servicios basado en dependencias, de modo que se “subsanaban” algunos problemas derivados de servicios que dependian unos de otros para arrancarse al iniciarse el sistema. Este sistema se llama LSB y el comando ahora es update-rc.d-insserv Mi solución utilizada Para utilizar este nuevo sistema, y lograr el proposito de tener un script que se ejecute al arrancar el sistema operativo, revisando alguna documentación. Como sol...

Thanks to: http://www.bonusbits.com/ Purpose This article gives the steps to open firewall ports on CentOS 6.x in Iptables IPv4. Basics Iptables rules can be changed on the fly by using the  iptables  binary. The rules that are set using iptables command are in memory only and will vanish when the daemon is restarted. The firewall rules added on the fly can be saved to the configuration file easily in CentOS/RHEL with the command  service iptables save This is no need to edit the configuration file unless you really want to. The following examples are aimed at hardening the inbound traffic, but allowing all outbound traffic. You can completely lock down all inbound, outbound and forwarded traffic if needed. It generally just causes a lot more administration and usually isn't necessary. Basic Commands iptables --flush  delete all firewall rules from memory. iptables --list  List current firewall policies service iptables save ...

Thanks to: http://www.cyberciti.biz/ This is very common scenario. You want to permit access to a remote machine only by SSH. You would like to block all incoming traffic to your system except ssh connection under Linux. Add following rules to your iptables shell script: /sbin/iptables -A INPUT -p tcp --dport 22 -j ACCEPT /sbin/iptables -A OUTPUT -p tcp --sport 22 -j ACCEPT   First rule will accept incoming (INPUT) tcp connection on port 22 (ssh server) and second rule will send response of incoming ssh server to client (OUTPUT) from our ssh server source port 22. However, iptables with kernel 2.4/2.6 provides very powerful facility to filter rule based upon different connection states such as established or new connection etc. Here is complete small script to do this task:   #!/bin/sh # My system IP/ set ip address of server SERVER_IP= "65.55.12.13" # Flushing all rules iptables -F iptables -X # Setting default filter policy iptables -P INPUT DROP ipta...

thanks to: http://www.binarytides.com/ Hardware information Like for every thing, there are plenty of commands to check information about the hardware of your linux system. Some commands report only specific hardware components like cpu or memory while the rest cover multiple hardware units. This post takes a quick look at some of the most commonly used commands to check information and configuration details about various hardware peripherals and devices. The list includes lscpu, hwinfo, lshw, dmidecode, lspci etc. 1. lscpu The lscpu command reports information about the cpu and processing units. It does not have any further options or functionality. $ lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 4 On-line CPU(s) list: 0-3 Thread(s) per core: 1 Core(s) per socket: 4 Socket(s): 1 NUMA node(s): 1 Vendor ID: GenuineIntel CPU family: ...