E3Switch DS3 Operating Information Manual - page 10
Chapter 4: Remote Management HTTP and SNMP
– SNMP VACM Security Warning –
As shipped, the default “safe_ro_view” is secure but not private.
View based access model VACM for SNMPv2c provides good restriction
of access to only specified statistics but no data privacy and
minimal user authentication. When a specific variable is enabled
for reading or writing, from a security perspective it should
be considered either public for reading or public for writing.
Alternatively, most configuration parameters can be set through
the HTTP password-protected interface which is secure.
Viewing snmpd.conf exposes it and community names to visibility by
3rd party network sniffers. All SNMPv2c data on the network
is visible. All community names can be "guessed" and, when used,
become visible to sniffers. Source IP addresses of requests
can be forged. Enabling a write community should be considered
insecure with respect to the specific view variables enabled.
Variables in the groups: interface, ds3, dot3 & mau, control the
link datapath; allowing write access allows disabling the link.
Specific variables disabled for all write users are secure.
Specific statistics disabled for all read users are invisible
and secure.
HTTP Management
The gateway contains a comprehensive, user-friendly HTTP management interface which allows a manager
to monitor bit-error-rates on the DS3/E3 link, lost packets, and user-friendly status messages at a single,
color-coded HTTP screen. A screenshot is available at
www.e3switch.com
. Most settings that can be
modified via SNMP can also be set through the HTTP interface in a more user-friendly manner.
Refer to the configuration section of this document for guidance on specific settings.
Event Log File
A timestamped log of operating status and events may be accessed at the HTTP management administration
page.
Resetting
Two options for resetting the gateway may be accomplished at the HTTP management administration page.
A management software reset will reset counters, statistics, MIB variables, and management software of the
gateway without interrupting data flow across the link. A hardware reset will temporarily interrupt link data
flow as if the gateway had experienced a power cycle. For new functionality to take effect, a hardware reset
is required after upgrading firmware but need not be initiated immediately. A software reset is not
appropriate after upgrading firmware, as only the management CPU would be reset while the packet transfer
CPU would be operating with the older, incompatible version of firmware.
SNMP
The gateway contains an SNMP agent which can respond to version 1 and version 2c requests for network
statistics from remote SNMP clients. The agent can also generate notifications of important network events
such as when network ports go up/down or experience high error rates. These trap notifications can be sent
to multiple hosts if desired, and using free or commercial software, the receiving hosts can log the
notifications or even generate email or pager messages for network managers.
SNMPv2c is inherently an insecure protocol, so the gateway implements VACM to restrict access to “safe”
statistics and settings. Please refer to the security discussion section of this document.
10