commmands

# starting mongodb 
/usr/bin/mongod -f /etc/mongod.conf 

# stoping firewalld.service and starting iptables.service
systemctl stop firewalld.service 
systemctl start iptables.service

# Deleting default rule of droping in forward table . now it will be able to forward the packets
iptables -t filter -D FORWARD 1
iptables -t filter -I FORWARD -j ACCEPT

# Redirecting packets going to port 80 and 443 to our machine ports 3128 and 3129 respectively
iptables -t nat -I PREROUTING -p tcp --dport 80 -i vboxnet0 -j DNAT --to-destination 10.20.48.1:3128
iptables -t nat -I PREROUTING -p tcp --dport 443 -i vboxnet0 -j DNAT --to-destination 10.20.48.1:3129

# Masquerading client's dns requests 
iptables -t nat -I POSTROUTING -p udp --dport 53 -o wlp6s0 -j MASQUERADE

# opening ports 3128 , 3129 for squid proxy server and port 10000 for our login manager.
iptables -t filter -I INPUT -p tcp --dport 10000 -j ACCEPT  
iptables -t filter -I INPUT -p tcp --dport 3128 -j ACCEPT 
iptables -t filter -I INPUT -p tcp --dport 3129 -j ACCEPT

# using selinux in permissive mode
setenforce 0