Geneko GWG, User Manual

Page: 147 / 158

147
User Manual
GWG Gateway
Figure
139
– Settings for virtual COM port
•
IP address: - (not used in server mode)
•
Port: 1234
•
Server Port: 1234
•
Port Name: COM10 (random selected)
After “Create COM” is activated if everything is alright in log will be shown message that port
COM10 is created, like in picture above. In communication with remote serial device COM10 should be
selected on workstation.
Firewall – example
Firewall implemented in GWG gateways has numerous options for matching interesting traffic. Traffic
flow is controlled through the gateway with three actions triggered by firewall:
1. ACCEPT – traffic is passed through the gateway without any changes implemented
2. REJECT – traffic is blocked with ICMP error messages
3. DROP – traffic is blocked without any error messages, connection is retried until the threshold for
retransmission is exceeded
By default all traffic is PERMITTED. To block all the traffic not defined under stated rules last entry in
firewall table should be DROP ALL.
Rule priority defines order by which gateway matches inspected packets. After first match between rule
and packet, no other rule is compared against matched traffic.
Firewall has 17 predefined rules for the most common usage. These 17 rules are following:
1.
Allow ALL from local LAN
All traffic originating from local subnet is allowed to access gateway Ethernet interface. It is important
to keep this rule enabled to prevent losing local management interface.
2.
Allow already established traffic
For inbound TCP only. Allows TCP traffic to pass if the packet is a response to an outbound-initiated
session.
3.
Allow TELNET on ppp_0
Accepts telnet connection from the outside to router’s WAN interface, for management over CLI