Completely remove nf_conntrack from kernel

1. Remove the following line, if it exists, in /etc/sysconfig/iptables-config
   IPTABLES_MODULES="ip_conntrack_netbios_ns"

2. Stop iptables
   iptables -F

3. Remove the related modules
   modprobe -r xt_NOTRACK nf_conntrack_netbios_ns nf_conntrack_ipv4 xt_state
   modprobe -r iptable_nat ipt_MASQUERADE nf_nat nf_defrag_ipv4
   modprobe -r nf_conntrack

nf_conntrack: table full, dropping packet.

Could be DoS/DDoS attack

echo 102400 > /proc/sys/net/netfilter/nf_conntrack_max
echo 120 > /proc/sys/net/netfilter/nf_conntrack_generic_timeout
echo 54000 > /proc/sys/net/netfilter/nf_conntrack_tcp_timeout_established
echo 30 > /proc/sys/net/netfilter/nf_conntrack_tcp_timeout_time_wait
sysctl -p

vi/vim settings

/etc/virc for vi
/etc/vimrc for vim
~/.vimrc

syntax on
set autoindent

set number

set sw=4
set tabstop=4
set cindent

Install Git on CentOS

Source1: http://www.davegardner.me.uk/blog/2010/01/29/setting-up-git-on-centos-5-server/

Source2: http://stackoverflow.com/questions/8059743/trying-to-install-git-on-centos-5-and-a-little-lost

Installing Git on CentOS 5 is easy if you make use of the EPEL (Extra Packages for Enterprise Linux) repository.

1. To setup EPEL all you need to do is create a file /etc/yum.repos.d/epel.repo and then paste in the following:

[epel]
name=Extra Packages for Enterprise Linux 5 - $basearch
#baseurl=http://download.fedoraproject.org/pub/epel/5/$basearch
mirrorlist=http://mirrors.fedoraproject.org/mirrorlist?repo=epel-5&arch=$basearch
failovermethod=priority
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL

[epel-debuginfo]
name=Extra Packages for Enterprise Linux 5 - $basearch - Debug
#baseurl=http://download.fedoraproject.org/pub/epel/5/$basearch/debug
mirrorlist=http://mirrors.fedoraproject.org/mirrorlist?repo=epel-debug-5&arch=$basearch
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL
gpgcheck=1

[epel-source]
name=Extra Packages for Enterprise Linux 5 - $basearch - Source
#baseurl=http://download.fedoraproject.org/pub/epel/5/SRPMS
mirrorlist=http://mirrors.fedoraproject.org/mirrorlist?repo=epel-source-5&arch=$basearch
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL
gpgcheck=1

2. Install GPG Keys


Go into rpm-gpg directory

cd /etc/pki/rpm-gpg/

Download GPG KEYS from https://fedoraproject.org/keys

wget https://fedoraproject.org/static/217521F6.txt

Rename to "217521F6.txt" to "RPM-GPG-KEY-EPEL"

cp 217521F6.txt RPM-GPG-KEY-EPEL

Remove "217521F6.txt" because we don't need in that file anymore

rm 217521F6.txt

If you want you can remove prefix lines from the file by vim and :wq (:Write and Quit)

vim RPM-GPG-KEY-EPEL

3. Installing git git-daemon

yum install git git-daemon