Specifications

UC864-E/G AT Commands Reference Guide

80304ST10041a Rev. 3 - 18/07/08

#FRWL - Firewall Setup

Command returns OK result code if successful.

Note: the firewall applies for incoming (listening) connections only.

Firewall general policy is DROP, therefore all packets that are not included

into an ACCEPT chain rule will be silently discarded.

When a packet comes from the IP address incoming_IP, the firewall chain

rules will be scanned for matching with the following criteria:

incoming_IP & <net_mask> = <ip_addr> & <net_mask>

If criteria is matched, then the packet is accepted and the rule scan is

finished; if criteria is not matched for any chain the packet is silently

dropped.

AT#FRWL? Read command reports the list of all ACCEPT chain rules registered in the

Firewall settings in the format:

#FRWL: <ip_addr>,<net_mask>

….

AT#FRWL=? Test command returns the allowed values for parameter <action>.

Example

Let assume we want to accept connections only from our

devices which are on the IP addresses ranging from

197.158.1.1 to 197.158.255.255

We need to add the following chain to the firewall:

AT#FRWL=1,"197.158.1.1","255.255.0.0"

Note For outgoing connections made with #SKTOP and #SKTD the remote host

is dynamically inserted into the ACCEPT chain for all the connection

duration. Therefore the #FRWL command shall be used only for defining

the #SKTL behaviour, deciding which hosts are allowed to connect to the

local device.

Rules are not saved in NVM, at startup the rules list will be empty.