Configuración de NAT en Core Linux con iptables

By delfirosales 19:23 Cisco IOS, Core Linux, Eve-ng, Firewall, Linux, Networking

Config de NAT con iptables

stop client dhcp

/etc/init.d/services/dhcp stop

Configure Eth0 (WAN)

$ sudo ifconfig eth0 10.1.100.33 netmask 255.255.255.0 up

Configure Eth1 (LAN)

$ sudo ifconfig eth1 192.168.11.1 netmask 255.255.255.0 up

Ruta de default

$ sudo route add default gw 10.1.100.253

Archivo resolv.conf

$ echo "nameserver 8.8.8.8" >> /etc/resolv.conf

Internet verification

$ nslookup cisco.com

Route verification

$ ip route get 8.8.8.8

Check if IP-Forwarding is enabled in the OS

$ sudo sysctl net.ipv4.ip_forward

0 = disabled

1 = enabled

Enable IP-Forwarding

$ sudo sysctl -w net.ipv4.ip_forward=1

Config NAT (PAT)

$ sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

Cisco SW

Switch(config-if)#ip add 192.168.11.2 255.255.255.0
Switch(config-if)#no sh
Switch(config-if)#exit
Switch(config)#ip dhcp excluded-address 192.168.11.1
Switch(config)#ip dhcp pool test
Switch(dhcp-config)#network 192.168.11.0 255.255.255.0
Switch(dhcp-config)#default-router 192.168.11.1
Switch(dhcp-config)#dns-server 8.8.8.8