iptables FORWARD rule

[favolas]

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Hello.

I'm running 3 virtual machines with Fedora 19. The machine B is set up with two networks adapters and provides que channel between machine A and machine C.

The machine A IP is set to 192.168.1.1 and machine C IP is set to 172.16.1.1. On machine B I have one adapter with IP 192.168.1.254 and another adapter with IP 172.16.1.254.

I've created this rule in machine B (it's working as a router):

iptables -P INPUT DROP

iptables -A INPUT -p icmp -j ACCEPT

And so, no connections between the machines are made unless the PING that allows the communication between machine A and B.

Now I want to create a rule in the router that allows the communication of HTTPS between the external network (machine C) and the internal network (machine A)

I've added this rule in machine B:

iptables -A FORWARD -o p7p1 -p tcp --dport 443 -d 192.168.1.1 -j ACCEPT

Where p7p1 is the interface on machine B that connects to machine A. I've also tried:

iptables -A FORWARD -i p8p1 -o p7p1 -p tcp --dport 443 -d 192.168.1.1 -j ACCEPT

Where p8p1 is the interface on machine B that connects to machine C.

Now, on machine A I do nc -l 443 and on machine C nc 192.168.1.1 443 but I'm getting Ncat: Connection timed out
Whats wrong with my rule?


Many thanks,

favolas

[zbilic]

Hi favolas,

did you setup proper routing on hosts A and C,
or is it host B default GW for both hosts?

[favolas]

Hello.

Thanks for your answer.

Here is the "router" (machine B) routing table:
G72XmuP.jpg

Machine A routing table
goxI6OY.jpg

And machine C routing table:
5PiLq4C.jpg

Is anything wrong?

favolas

[zbilic]

Hi favolas,

According to Figure for the router "C", you do not have the proper route set for network 192.168.1.0/24.

GW for network 192.168.1.0/24 is not 172.16.1.1, should be 172.16.1.254.

Packet from the host "A" will be returned over the default gateway.

Traffic path you can check with tcpdump on each host (interface).

Also, I do not know why host "C" has two default gateways.

Regards

[favolas]

Thanks.

That was the problem..

Regards