Shulou(Shulou.com)06/01 Report--

SNAT: source address translation, used to change one address of an ip packet to another

A: 192.168.100.100 eth0 user

B: 192.168.100.1 eth0

192.168.200.200 eth2 Firewall

C: 192.168.200.100 eth0 web container

A-> C

A-> B

B-> C

A user, visit the website on C, SNAT conversion process, A first visit B, that is, the fire situation of 192.168.100.1, and then visit the C website through the 192.168.200.200 of the firewall

The configuration process is as follows:

1) A: configure eth0 gateway: 192.168.100.1

2) B: configure eth2 gateway: 192.168.200.1

Note: gateway for configuring network card under suse: route add-net 192.168.200.200 netmask 255.255.255.0 gw 192.168.200.1 dev eth2

First of all, B needs to activate route forwarding:

Grep forward / etc/sysctl.conf | grep-v ^ #

Net.ipv4.ip_forward = 1

Secondly, configure the firewall to forward An access C to B access C.

That is, 192.168.100.100 Murray-> 192.168.200.100

Process: 192.168.100.100-> 192.168.200.200

192.168.200.200-> 192.168.200.100

Routing rules for iptables:

-A POSTROUTING-s 192.168.100.100-o eht0-j SNAT-- to-source 192.168.200.200

At this point, the DNAT is set up; next is the test.

Restart the firewall, or reload the firewall configuration file: / etc/init.d/iptables reload

Then, grab the bag and watch the interview process.

Tcpdump-i any port 80-s 0-w saved package name

DNAT: maps a set of local internal addresses to a set of global internal addresses

A: 192.168.100.100 eth0 user

B: 192.168.100.1 eth0

192.168.200.200 eth2 Firewall

C: 192.168.200.100 eth0 web container

A-> B

A-> B

B-> C

A user, visit Brector SNAT conversion process, A visits B, that is, 192.168.100.1 of the fire situation; in fact, the access process is that An accesses B, that is, 192.168.100.1 of the fire situation, and then firewall B accesses the web container of 192.168.200.100 C through 192.168.200.200

The configuration process is as follows:

1) C: configure eth0 gateway: 192.168.200.1

2) B: configuration

Eth0 Gateway: 192.168.100.1

Eth2 Gateway: 192.168.200.1

Note: gateway for configuring network card under suse: route add-net 192.168.200.200 netmask 255.255.255.0 gw 192.168.200.1 dev eth2

First of all, B needs to activate route forwarding:

Grep forward / etc/sysctl.conf | grep-v ^ #

Net.ipv4.ip_forward = 1

Secondly, configure the firewall to forward An access C to B access C.

Iptables-t nat-A PREROUTING-d 192.168.100.1-p tcp-m tcp-deport 80-I eth0-j DNAT-todestionation 192.168.200.100

Restart the firewall, or reload the firewall configuration file: / etc/init.d/iptables reload

Then, grab the bag and watch the interview process.

Tcpdump-i any port 80-s 0-w saved package name

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