/sbin/service xinetd stop; /sbin/chkconfig xinetd off
rm -rf /etc/xinetd.d
6、禁止一些 /etc/init.d/ 下面不需要的服务，更多信息请参考 “Understanding your (Red Hat Enterprise Linux) daemons, by Len DiMaggio”。
/sbin/chkconfig --list
for a in acpid anacron apmd atd autofs bluetooth cpuspeed cups gpm
hidd ip6tables irqbalance messagebus microcode_ctl netfs nfs nfslock
pcscd portmap readahead_early readahead_later rpcgssd rpcidmapd
sendmail smartd xinetd yum-updatesd; do /sbin/chkconfig $a off; done
7、重启系统后，检查一下正在运行中的服务，看看是不是都是必须的。
netstat -an | grep LISTEN
netstat -atunp
8、为了安全起见，删除一些不需要的用户。
cp /etc/passwd /etc/passwd.sav
cp /etc/group /etc/group.sav
for a in adm lp sync news uucp operator games gopher mailnull nscd rpc;
do /usr/sbin/userdel $a -f; done
for a in lp news uucp games gopher users floopy nscd rpc rpcuser nfsnobody;
do /usr/sbin/groupdel $a -f; done
vi /etc/inittab
# Run gettys in standard runlevels
#1:2345:respawn:/sbin/mingetty tty1
#2:2345:respawn:/sbin/mingetty tty2
...
16、加固 SSH 安全。
vi /etc/ssh/sshd_config
Port 2222
Protocol 2
PermitRootLogin no
PermitEmptyPasswords no
X11Forwarding no
UsePAM no
UseDNS no
AllowUsers vpsee
Banner /etc/issue
vi /etc/sysctl.conf
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.all.accept_redirects = 0
定制 Linux 内核
19、定制，编译，安装 Linux 内核。
yum install rpm-build ncurses ncurses-devel
rpm -ivh kernel-2.6.18-8.1.1.el5.data-original.rpm
cd /usr/data-original/redhat/SPECS
rpmbuild -bp --target i686 kernel-2.6.spec
cd /usr/data-original/redhat/BUILD/kernel-2.6.18/linux-2.6.18.i686
sed -i 's/EXTRAVERSION = -prep/EXTRAVERSION = -8.1.1.custom.el5/' Makefile
make menuconfig
make rpm
cd /usr/data-original/redhat/RPMS/i686
rpm -ivh kernel-2.6.18prep-1.rpm
/sbin/mkinitrd /boot/initrd-2.6.18-prep.img 2.6.18-prep (2.6.18-prep -> /lib/modules)
vi /boot/grub/menu.1st
20、修改 iptables，只允许 ssh，http 和 https 端口打开。
/sbin/iptables -F
/sbin/iptables -A INPUT -i lo -j ACCEPT
/sbin/iptables -A INPUT -i ! lo -d 127.0.0.0/8 -j REJECT
/sbin/iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
/sbin/iptables -A OUTPUT -j ACCEPT
/sbin/iptables -A INPUT -p tcp --dport 80 -j ACCEPT
/sbin/iptables -A INPUT -p tcp --dport 443 -j ACCEPT
/sbin/iptables -A INPUT -p tcp -m state --state NEW --dport 22 -j ACCEPT
/sbin/iptables -A INPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT
/sbin/iptables -A INPUT -j REJECT
/sbin/iptables -A FORWARD -j REJECT
然后查看一下 iptables：
iptables -L
更多信息
10 Realistic Steps to a Faster Web Site
Understanding your (Red Hat Enterprise Linux) daemons, by Len DiMaggio
Linux Server Security (2nd Edition), by Michael D. Bauer, O’Reilly
Hardening Linux, by James Turnbull, Apress
RHEL 5.0 Deployment Guide, by RedHat
RHEL 5.0 Installation Guide, by RedHat
smartctl version 5.37 ‘i686-pc-linux-gnu‘ Copyright (C) 2002-6
Bruce Allen
Home page is http://smartmontools.sourceforge.net/=== START OF INFORMATION SECTION ===
Model Family: Western Digital Caviar SE (Serial ATA) family
Device Model: WDC WD800JD-00MSA1
Serial Number: WD-WMAM9S474555
Firmware Version: 10.01E01
User Capacity: 80,026,361,856 bytes
Device is: In smartctl database ‘for details use: -P show‘
ATA Version is: 7
ATA Standard is: Exact ATA specification draft version not
indicated
Local Time is: Thu Feb 7 13:09:37 2008 PST SMART support is: Available - device has SMART capability. SMART support is: Disabled