It doesnt matter if I configure it with the command line or with the firewalld-GUI. After I rebooted the machine all network devices are assigned to the default zone. Reload the firewall rules and test pings from the internal machines: firewall-cmd -complete-reloadĦ Responses to “CentOS 7 as NAT Gateway for Private Network”
![centos 7 static ip gateway centos 7 static ip gateway](https://www.linglom.com/wp-content/uploads/2017/03/Configure-static-IP-address-on-CentOS-7-06.png)
I was running DNS, DHCP, pxe and several other services from my RTR001 machine to service the internal computers so I opened those ports with: firewall-cmd -permanent -zone=internal -add-service=dhcpįirewall-cmd -permanent -zone=internal -add-service=tftpįirewall-cmd -permanent -zone=internal -add-service=dnsįirewall-cmd -permanent -zone=internal -add-service=httpįirewall-cmd -permanent -zone=internal -add-service=nfsįirewall-cmd -permanent -zone=internal -add-service=ssh Now the NAT rule (see comments – this may not be required): firewall-cmd -permanent -direct -passthrough ipv4 -t nat -I POSTROUTING -o eth0 -j MASQUERADE -s 192.168.0.0/24 If you have made a mistake you can remove the interface from the zone with: firewall-cmd -zone=internal -remove-interface=eth0Ĭonfigure masquerading on the externally facing device (eth0): firewall-cmd -zone=external -add-masquerade -permanent On CentOS 7, after configuring both network interfaces, we need to use firewalld: firewall-cmd -zone=external -add-interface=eth0 -permanentįirewall-cmd -zone=internal -add-interface=eth1 -permanentĪfter making changes reload with: firewall-cmd -complete-reloadĬheck the settings to ensure your interfaces are listed in the correct zone: To avoid rebooting implement the same change dynamically: sysctl -w _forward=1 So the router machine (RTR001) has the following interfaces and IP addresses:Ĭonfigure the kernel to forward IP packets: /etc/nf This machine (RTR001) will take traffic from the private network 192.168.0.* and route it out via its other interface to the internet etc. One with an address on the 192.168.0.* network and another providing wider network (& internet) access on a 123.111.123.* network. One of the machines (let’s call it RTR001) on the network has two network interface cards.
![centos 7 static ip gateway centos 7 static ip gateway](https://www.linglom.com/wp-content/uploads/2017/03/Configure-static-IP-address-on-CentOS-7-02.png)
![centos 7 static ip gateway centos 7 static ip gateway](https://www.cyberciti.biz/media/new/faq/2016/08/network-config.jpg)
The scenario is a small private network connected via a switch and using 192.168.0.* addresses.