Configuring the firewall and vpn, Route based virtual private networking – RuggedCom RuggedRouter RX1000 User Manual

Page 112

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Source-Port

The tcp/udp port the connection originated from.

Original-
Destination-IP

The destination IP address in the connection request as it was
received by the firewall.

Rate-Limit

A specification which allows the rate at which connections are
made to be limited.

User-Group

A method of limiting outbound traffic from the firewall to a
specific user, group of users and a specific application.

Some examples will illustrate the power of the rules file:

Rule Action

Source-Zone

Destination-Zone Protocol Dest-

Port

Source-

Port

Original-

Destination-IP

1 ACCEPT net:204.18.45.0/24 fw

2 DNAT

net

loc:192.168.1.3

tcp

ssh, http

3 DNAT

net:204.18.45.0/24 loc:192.168.1.3

tcp

http

-

130.252.100.69

4 ACCEPT fw

net

icmp

5 ACCEPT net:204.18.45.0/24 fw

icmp

8

1) This rule accepts traffic to the firewall itself from the 204.18.45.0/24

subnet. If the

default policy is to drop all requests from net to the firewall, this rule will only
traffic from the authorized subnet.

2) This rule forwards all ssh and http connection requests from the Internet to local

system 192.168.1.3.

3) This rule forwards http traffic from 204.18.45.0/24 (which was originally directed

to the firewall at 130.252.100.69) to the host at 192.168.1.3 in the local zone. If
the firewall supports another public IP address (e.g. 130.252.100.70), a similar
rule could map requests to another host.

4) and 5) These rules allow the firewall to issue icmp requests to the Internet and to

respond to icmp echo requests from the authorized subnet.

Rules are defined in the file /etc/shorewall/rules and are modified from the Firewall
Rules
menu.

Configuring The Firewall And VPN

Route Based Virtual Private Networking

Begin configuration by creating local, network and vpn zones (all as zone type IPV4).
The openswan daemon will have created ipsecX interfaces which should be added to
the vpn zone in the interfaces menu.
The IPsec protocol operates on UDP port 500 and using protocols ah (Authentication
Header) and Encapsulating Security Payload (ESP) protocols. The firewall must
accept this traffic in order to allow IPsec. If the firewall serves as the VPN gateway,
add the following rules:

Action

Source-Zone Destination-Zone Protocol Dest-Port

ACCEPT

all

fw

ah

ACCEPT

all

fw

esp

ACCEPT

all

fw

udp

500

110 RuggedCom

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