Examples; Creating A Chat Script; Creating A Simple Firewall; Controlling Access During Weekend Hours - Lantronix SCS Reference Manual

Additional Remote Networking

5.8 Examples

5.8.1 Creating a Chat Script

Figure 5-25 displays a sample chat script. This script will send a series of text strings to the remote host, and
will expect particular strings in return. If an expected string is not received from the remote host, the script
will loop up to four times before the entire script fails.
Local>> DEFINE SITE irvine CHAT TIMEOUT 4 FAIL
Local>> DEFINE SITE irvine CHAT SEND ""
Local>> DEFINE SITE irvine CHAT EXPECT "login:"
Local>> DEFINE SITE irvine CHAT SEND "user"
Local>> DEFINE SITE irvine CHAT EXPECT "word:"
Local>> DEFINE SITE irvine CHAT SEND "password"

5.8.2 Creating a Simple Firewall

Firewalls are used to protect a network or networks from unauthorized access. To set up a firewall, a filter
list is used; packet traffic is compared to the filters in the list to determine whether or not it will be
forwarded. In general, firewalls prevent all packet traffic, with the exception of traffic to a particular service
or services.
In this example, a network policy prevents all IP traffic, permitting only ICMP ping packets and email.
Telnet connections are permitted to only one secure host (192.0.1.4) on the local network. The SCS is
calling site memphis.
First, create a filter list for IP traffic. This list is called mem.
Local>> DEFINE FILTER mem CREATE
Local>> DEFINE FILTER mem ALLOW IP ICMP
Local>> DEFINE FILTER mem ALLOW IP TCP DPORT EQ SMTP
Local>> DEFINE FILTER mem ALLOW IP DST 255.255.255.255 192.0.1.4 TCP DPORT EQ TELNET
Local>> DEFINE FILTER mem ADD DENY ANY
Finally, the mem filter list must be associated with site memphis as an incoming filter list.
Local>> DEFINE SITE memphis FILTER INCOMING mem
For a more complex firewall example, see Creating a Firewall on page 11-30.
Note:

5.8.3 Controlling Access During Weekend Hours

Configurable time ranges are based on a Sunday-to-Saturday week. If you want to allow or restrict access
for a time period that spans Saturday and Sunday, you need to use multiple commands.
Figure 5-25: Creating a Chat Script
Figure 5-26: Creating IP Filter
Figure 5-27: Assigning mem Filter List to Site memphis
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Examples