Enterasys Networks Security Router X-PeditionTM - Manual (Page 40)

Utilizing the Command Line Interface
2-4 Managing the XSR
PuTTY and other shareware programs are compatible with the XSR’s SSH server.
Refer to the XSR Getting Started and CLI Reference guides for more details.
Accessing the Initial Prompt
The CLI is protected by security. Before you can access EXEC mode, you must enter a valid
password. This mode lets you test basic connectivity of the XSR but does not permit you to change
or monitor the router’s configuration. Access to enhanced commands is permitted only if you
enter Privileged EXEC mode by entering
enable . You can logout at any time by entering exit
while in EXEC mode. Refer to Table 2-1 for session limits.
The show resources command displays all resources created and the memory utilized. Refer to
the XSR CLI Reference Guide for more details.
Synchronizing the Clock
XSR 1800 and 3000 Series routers have an on-board Real Time Clock (RTC) chip with which to
keep accurate time across the network. As an alternative to accessing a public time server, you can
utilize the RTC as a time reference for isolated networks employing the Simple Network Time
Protocol (SNTP). XSR 1200 Series routers do not carry an RTC chip, however, and for these you
must
synchronize from an external source.
The XSR supports both SNTP v3 client and server (unicast mode) to synchronize logs on routers,
switches and other network devices. Scenarios include isolated “flat” or hierarchical topologies as
well as public time-server schemes. A flat scenario, for instance, might have Router A (XSR 3150)
acting as a server to both Router B (XSR-1220) and Router C (XSR-1220) which makes a client
request through Router B via an ISDN connection. A hierarchical scenario, on the other hand,
might have Router B acting as both SNTP client and server, making a client request of Router A
and taking a client request from Router C over ISDN.
SNTP client and server are configured with the sntp-client server [primary |
A.B.C.D.][alternate | A.B.C.D.] and sntp-server enable commands, respectively. Also,
you can also set the interval between client requests with the sntp-client poll-interval
command.
Refer to the XSR Getting Started Guide for a configuration example and the XSR CLI Reference Guide
for command details.
Table 2-1 Session Limits
Parameter Limit
Total number of CLI Telnet/SSH sessions permitted 5
SSH sessions permitted with 32 MBytes of memory 1
Console sessions permitted 1
Number of Telnet sessions reserved for administrators 1
Terminal auto-logout timeout value (configurable) 1800 seconds
Note: We recommend using an NTP time server over an SNTP server with an RTC as its primary
source for greater accuracy. In this respect, the default stratum is set internally to 10.