Operation Manual

SNMP
202 ViewCast
SNMP UDP Ports Used by SNMP Manager and
SNMP Agents
UDP Port for SNMP Requests
SNMP request messages are sent from SNMP manager to SNMP agent. When the external SNMP
manager expects to “talk” to the ViewCast SNMP agent, it sends SNMP requests to the ViewCast SNMP
agent over the default SNMP UDP port 161 with the following parameters:
 Correct IP address of the encoder system
 Other parameters such as an appropriate community name
Note: For SNMP v1/v2c version, a community name is treated as a password to access the resources
managed by the SNMP agent. Different community names can have different access rights such
as NOTIFY ONLY, READ ONLY, WRITE ONLY, READ WRITE and READ CREATE etc.
You can configure the ViewCast SNMP agent to receive SNMP requests over a different UDP port other
than 161. You also have the option to configure the ViewCast SNMP agent to receive SNMP requests
over a different UDP port other than 161. Refer to information in this section on how to make these
changes.
Note: Once the SNMP UDP port is configured, you don’t have to manually enable it in the firewall
setting. Instead, it is automatically enabled when the ViewCast SNMP agent is started.
UDP Port for SNMP Traps
SNMP traps are sent from the SNMP agent to the SNMP trap listener. You can monitor and receive
SNMP traps over UDP port 162 from one or multiple SNMP-enabled Niagara systems. Perform the
following to monitor and receive SNMP traps:
 Configure the IP address where the SNMP trap listener runs as one of the trap destinations for
each affected ViewCast SNMP agent.
 Configure the corresponding community name.
 Keep running an SNMP trap listener application to monitor traps over SNMP UDP port 162 with an
appropriate community name.
 Allow the trap listener to pass through the firewall on UDP port 162.
Note: Choosing a trap listener is up to you. The trap listener doesn’t have to run on the system.
Instead, it runs in a centralized location.