SNMP Trap Overview

The system generates SNMP traps according to operating specifications defined in supported MIBs. This section provides information for:

IP Hosts

Traps are sent to IP hosts. The IP hosts are configured in a proprietary trap host table maintained by the router (the server). Each entry in the table contains:

The maximum number of entries in the SNMP trap host table in each virtual router is eight.

Trap Categories

The router supports the following trap categories:

To enable global trap categories, use the snmp-server enable traps command. To enable trap categories for a specific host, use the snmp-server host command. For more information about enabling global trap categories and traps categories for a specific host, see Enabling and Configuring the Trap Severity Level on a Global Basis and Configuring an SNMP Trap Host.

Trap Severity Levels

The router provides a method of filtering traps according to severity. Table 22 describes the supported severity levels.

Table 22: Trap Severity Descriptions

Severity Number

Severity Name

System Response

0

Emergency

System unusable

1

Alert

Immediate action needed

2

Critical

Critical conditions exist

3

Error

Error conditions exist

4

Warning

Warning conditions exist

5

Notice

Normal but significant conditions exist

6

Informational

Informational messages

7

Debug

Debug messages

You can set up one or more of the following types of trap filters:

Trap filters work as follows:

  1. An event is posted to the SNMP agent.
  2. The system determines whether the corresponding trap category is globally enabled and whether the trap meets the minimum severity level for the trap category. If the per-category filter is not defined for this trap, the global trap severity applies.
    • If the trap does not meet these criteria, the system discards the trap.
    • If the trap does meet these criteria, the trap goes to the trap host processor.
  3. The trap host processor determines whether the trap category is enabled on the host and whether the trap meets the minimum severity level set for the host.
    • If the trap does not meet these criteria, the system discards the trap.
    • If the trap does meet these criteria, the trap is sent to the trap recipient.

To set up global severity filters, use the snmp-server enable traps command. To specify the trap severity level for a particular category, use the snmp-server enable traps per-category-trapFilters command. To set up a severity filter for a specific host, use the snmp-server host command. For more information about configuring severity filters, see Enabling and Configuring the Trap Severity Level on a Global Basis, Enabling and Configuring the Trap Severity Level on a Per-Category Basis, and Configuring an SNMP Trap Host.

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