Easy to use Linux to turn on routing and forwarding functions.

Mark, today want to let a REDHAT7 open iptables NAT forwarding function, find a half day.

A server: 192.168.30.20/24

b Server: 192.168.30.1/24,eth0; 192.168.40.1/24,eth1

C Server: 192.168.40.20/24

Goal: Allow A to ping and ssh to the C machine. This will need to jump through the B server.

Operation Process:

1. Turn on the kernel route forwarding parameter on the B server

Temporary entry into force:

echo "1" >/proc/sys/net/ipv4/ip_forward

For permanent entry, you need to modify the sysctl.conf:

Net.ipv4.ip_forward = 1

Execution Sysctl-p Immediate effect

2, b server turn on iptables NAT forwarding

Iptables-t nat-a postrouting-s 192.168.30.0/24-d 192.168.40.0/24-o eth1-j Masquerade

# Configure the Source Address 30 network segment, Destination address 40 segment of the address translation, from the ETH1 network card out.

Iptables-t nat-a postrouting-s 192.168.40.0/24-d 192.168.30.0/24-o eth0-j Masquerade

#配置源地址40网段, address translation of the destination address 30 network segment, from the Eth0 NIC.

Permanent Save: Iptables-save >/etc/sysconfig/iptables

TIP: note the corresponding network card.

3. Set the route to B server IP on a and C servers

A:route add-net 192.168.40.0 netmask 255.255.255.0 GW 192.168.30.1

C:route add-net 192.168.30.0 netmask 255.255.255.0 GW 192.168.40.1

This article is from the "Danielqu" blog, make sure to keep this source http://qujunorz.blog.51cto.com/6378776/1884459

Easy to use Linux to turn on routing and forwarding functions.