Server Admin – Page 9

Sep 28

Prevent DDOS Attack

By Dhillon Server Admin One Comment

Prevent DDOS Attack
(D)DoS-Deflate script monitors and tracks the IP addresses that are sending and establishing large amount of TCP network connections. When it detects number of connections from a single IP that exceeds certain preset limit, the script automatically uses APF or IPTABLES to ban and block the IPs.

Installation:

wget http://www.inetbase.com/scripts/ddos/install.sh
chmod 0700 install.sh
./install.sh

UnInstall:

wget http://www.inetbase.com/scripts/ddos/uninstall.ddos
chmod 0700 uninstall.ddos
./uninstall.ddos

Sep 28

.htaccess Bad Bot Block

By Dhillon Server Admin No Comments

.htaccess Bad Bot Block

ErrorDocument 403 /403.html
SetEnvIfNoCase ^User-Agent$ .*(useragent1|useragent2|useragent3) BADBOT
SetEnvIfNoCase ^User-Agent$ .*(useragent4|useragent5|useragent6) BADBOT
SetEnvIf remote_addr xx.xx.xx.xx BADBOT
Deny from env=BADBOT

Sep 26

Free up Linux memory

By Dhillon Server Admin No Comments

Free Clear Purge System memory ( RAM ) in Linux.

Its best to leave the memory management to linus kernel but if you must clear up some memory then this is how you do it.
Execute this command as root:

sync; echo 3 > /proc/sys/vm/drop_caches

What does it do ?
sync; will write all the unwritten data to disk so that nothing is lost.
echo 3 > /proc/sys/vm/drop_caches; will drop all the cached data from memory.