Ping Requests use ICMP protocols. This is enabled/disabled using sysctl values.
To Disable Ping:
 
echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_all
 
To Enable Ping:
 
echo 0 > /proc/sys/net/ipv4/icmp_echo_ignore_all

Please follow the steps to install BFD
 
Download Source package from source
wget http://www.r-fx.ca/downloads/bfd-current.tar.gz
Extract the source 
tar -zxf bfd-current.tar.gz
cd bfd*
./install.sh
adding Ips to ignore.hosts file 
echo IP >> /usr/local/bfd/ignore.hosts
 replace ‘ALERT_USR=”0″‘ ‘ALERT_USR=”1″‘ — /usr/local/bfd/conf.bfd

/usr/local/sbin/bfd -s
 

Finished

Hi guys…
On this documentation… Will help you to setup linux server as a network gateway without installing any proxy softwares….
#!/bin/sh
# The interface conneected to Your LAN
INTIF=”eth1?
# The interface conneected to Internet (ppp0 or eth)
EXTIF=”eth0?
# If you have a static IP (Public IP), Use the following line. Otherwise comment following line …