PollCat NetLink II - User’s Guide
38. Email / Txt Msg: This item is used to deﬁne parameters that are
employed when the NetLink II automatically generates an email or
text message in order to notify the operator that an alarm has been
detected. Note that these same parameters are also used when the
"Scheduled Actions" feature is conﬁgured to send email or text
messages. Email parameters are described further in Section 184.108.40.206.
39. PPP Dialout: When a cable Ethernet connection is not available, the
PPP Dialout feature allows the NetLink II to dial out to an internet
service provider, in order download stored call data. PPP Dialout
parameters are described in detail in Section 220.127.116.11.
18.104.22.168. The IP Security Feature
NetLink II can restrict unauthorized IP addresses from establishing an
inbound Telnet connection to the unit. This allows the user to grant Telnet
access to only a speciﬁc group of IP addresses, or block a particular
IP address. In the default state, the NetLink II accepts incoming IP
connections from all hosts.
The IP Security Function employs a TCP Wrapper program which allows
the use of standard, Linux operators, wild cards and net/mask pairs to create
a host based access control list.
As shown in Figure 5.14, the IP Security conﬁguration menu allows you
to deﬁne a "hosts.allow" client list and "hosts.deny" client list. Basically,
when setting up IP Security, you must enter IP addresses for the hosts that
you wish to allow in the Allow list, and addresses for hosts that you wish
to deny in the Deny list. Since Linux operators, wild cards and net/mask
pairs are allowed, these lists can indicate speciﬁc addresses, or a range of