Change runlevel Settings for a Group of Services

The following command changes all services set to run at runlevel 5 and sets them to off.

chkconfig --list | grep 5:on | awk '{ print $1 }' | \
 while read LINE; do chkconfig --level 12345 $LINE off; done

Network Access Control

Enterasys has a mature and unmatched product offering, today.

http://www.enterasys.com/products/index.aspx

 

Fact Sheet NSA Suite B Cryptography [08dec2008]

Key length recommendations from the NSA for companies making products for Gov't use.

http://www.keylength.com/en/6/

 

Apache Worker vs. Prefork

This is a good post.

http://www.camelrichard.org/apache-prefork-vs-worker

Good Hints:
Worker is superior in 2+ cpu applications
Compile PHP5 after installing Apache

Restoring Hard Links to Protected Files in Linux

I got this syslog message today:

Dec 4 9:47:56 [hostname] restorecond: Will not restore a file with more than one hard link (/etc/resolv.conf) Invalid argument

Here is how I resolved it:

$ sudo ls -i /etc/resolv.conf # find innode
[inode number] /etc/resolv.conf

$ sudo find /etc -inum [inode number] # find hard links
$ /usr/sbin/lsof | grep resolv.conf # check if file is open
$ mv /etc/sysconfig/networking/profiles/default/resolv.conf ~ # move
$ sudo restorecon /etc/resolv.conf # set selinux defaults
$ sudo ln /etc/resolv.conf /etc/sysconfig/networking/profiles/default/resolv.conf #recreate hard link

 

DDOS Incident Cheat Sheet

This is very well put together:

http://www.zeltser.com/network-os-security/ddos-incident-cheat-sheet.pdf

 

Using SSH Remote and Local Tunnels

The following example demonstrates how to use Remote and Local SSH tunneling to access a service on your highly secure home computer (that's not exposed explicitly through a firewall at your home) from a remote location.

For example:

On Home Computer, before traveling:
ssh -R 44444:localhost:22 user@remote.computer.ip.address

On Remote Computer, after arriving at work:
ssh -L 22222:localhost:44444 user@remote.computer.ip.address (possibly rfc1918 ip)
ssh user@localhost -p22222

Wa la, you now have a SSH session to your home computer from work.