Security Gateway Manual
SG-3100
Description
Text describing the rule, e.g.
Guest LAN outbound on WAN
• Click
Save
• Click
Apply Changes
Alternately, clone existing NAT rules and adjust as needed to match the new LAN.
2.6.6 Firewall Rules
By default there are no rules on the new interface, so the firewall will block all traffic. This is not ideal for a LAN as
generally speaking, the LAN clients will need to contact hosts through the firewall.
Rules for this interface can be found under
Firewall > Rules
, on the
OPTx
tab (or the custom name, e.g.
GUESTS
).
There are two common scenarios administrators typically choose for local interfaces: Open and Isolated
Open
On an open LAN, hosts in that LAN are free to contact any other host through the firewall. This might be a host on
the Internet, across a VPN, or on another local LAN.
In this case a simple “allow all” style rule for the interface will suffice.
• Navigate to
Firewall > Rules
, on the
OPTx
tab (or the custom name)
• Click
to add a new rule at the top of the list
• Configure the rule as follows:
Action
Pass
Interface
OPTx
(or the custom name) should already be set by default
Protocol
Any
Source
OPTx Net
(or the custom name)
Destination
Any
Description
Text describing the rule, e.g.
Default allow all from OTPx
• Click
Save
• Click
Apply Changes
• Add rule to pass any protocol from interface net to any destination
Isolated
In an isolated local network, hosts on the network cannot contact hosts on other networks unless explicitly allowed
in the rules. Hosts can still contact the Internet as needed in this example, but that can also be restricted by more
complicated rules.
This scenario is common for locked down networks such as for IOT devices, a DMZ with public services, untrusted
Guest/BYOD networks, and other similar scenarios.
Warning:
Do not rely on tricks such as using policy routing to isolate clients. A full set of reject rules as described
in this example are the best practice.
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