Afar AR24027, Руководство оператора

Страница: 63 / 100

AR24027 Operator’s Manual
5-2
If after entering the public login name, the terminal displays the message “Login Failed”, this may be
due to the radio being configured to be managed from only some specific IP addresses. This is
explained in the following section.
5.1.3 Telnet Security
The remote management capability through Telnet opens the possibility for an unauthorized user to
login to any radio accessible through the Internet. The radio configuration can be password protected
with the use of the
lock and unlock commands. If further security is desired you can specify up to
four source IP addresses that are authorized to initiate Telnet sessions with the radio. When
configured in this way, the radio will reject Telnet requests from all IP addresses that are not in the
authorized list.
The authorized source IP addresses for Telnet are the same addresses that are authorized to perform
SNMP management. They are entered using the
snmp command described in section 4 and can be
viewed with the display-configuration command. When this list is empty, you can initiate a Telnet
session from any IP address with the login name public . When this list is not empty, Telnet sessions
can only be initiated from the listed hosts. Additionally, for each host, the login name must match the
string listed for the
community field.
If you wish to use this security feature you need to know the IP address of the local machine. On a
PC running Windows, one way to find its IP address is to open a DOS window and issue the
command:
>ipconfig
5.2 SNMP
5.2.1 Command Line Interface Versus SNMP
Configuration settings on the AR24027 are displayed and modified using a command line interface,
which can be accessed using either the RS-232 console port, the ECONSOLE program, or via a
TELNET session.
In a NOC environment, there is a need for an automated monitoring system to collect on an ongoing
basis information from devices in the network for three purposes:
1) to build an inventory of all the devices of the network
2) to keep track of all devices on the network and raise alarms when any device becomes
unreachable (device failed, link down, etc)
3) to maintain statistics on traffic levels in order to implement usage-based charging, or to determine
where congestion exists in the network, so that the network can be expanded to accommodate
growth
Command line interfaces are not very suitable for these purposes, and the AR24027 supports the
Simple Network Management Protocol (SNMP) to assist in these tasks. SNMP is a simple,