Setting up NAT
Current NAT server is natrium.club.cc.cmu.edu
Setting up NAT gateway
See https://wiki.club.cc.cmu.edu/org-auth/ccwiki/natrium.club.cc.cmu.edu
See http://www.bctes.com/nat-linux-iptables.html
Ensure that machine has 2 NIC.
In this guide eth0 is external and eth1 is internal
Modify /etc/sysctl.conf, uncomment:
net.ipv4.ip_forward=1
Modify /etc/rc.local, add:
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE iptables -A FORWARD -i eth1 -j ACCEPT
Execute
echo 1 > /proc/sys/net/ipv4/ip_forward iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE iptables -A FORWARD -i eth1 -j ACCEPT
Change <private address> to local address
ifconfig eth1 <private address>
Modify /etc/network/interfaces, add:
# nat interface auto eth1 iface eth1 inet static address <private address> netmask 255.255.255.0
Adding machines to NAT
Assuming you want to add br1 to natrium as 10.0.2.2
Temporary
ifconfig eth1 10.0.2.2 netmask 255.255.255.0 broadcast 10.0.2.255 route add default gw 10.0.2.1 br1
Permanent
Modify br<interface> in /etc/network/interfaces:
auto br<interface>
iface br<interface> inet static
address 10.0.2.2
netmask 255.255.255.0
network 10.0.2.0
broadcast 10.0.2.255
gateway 10.0.2.1
# dns-* options are implemented by the resolvconf package, if installed
dns-nameservers 128.237.157.12 128.237.157.14
dns-search club.cc.cmu.edu
bridge_ports eth<interface#>