SNMPv1 Trap (`snmp_trap`)

Layer: Application and control
Header: variable length
Notes: Application protocols

Reached from

Lower layer	Selector	Value
`snmp_pdu`	`pdu_type`	164 (0xa4) (re-decodes this layer)

Fields

Field	Type	Default	Auto	Description
`pdu_type`	`enum(8)`	`164` (trap)		PDU tag (0xa0 GetRequest, 0xa2 Response, 0xa4 v1 Trap, 0xa7 SNMPv2-Trap, …).
`pdu_length`	`uint(8)`		Length of the header and payload in octets (`-2`)	BER length of the PDU contents (Auto; short form, below 128).
`body`	`tlv` — rest of the PDU	6 items		Trap contents as BER TLVs: enterprise, agent-addr, generic-trap, specific-trap, time-stamp and variable bindings.

`pdu_type`

Value	Name
164 (0xa4)	`trap`

`body`

Type 8 bits, length 8 bits.
The length counts the value only.
Unknown types are kept as raw value octets.

Type	Name	Value fields	Description
2 (0x02)	`integer`
4 (0x04)	`octet_string`
5 (0x05)	`null`
6 (0x06)	`object_identifier`
64 (0x40)	`ip_address`	`address`
65 (0x41)	`counter32`
66 (0x42)	`gauge32`
67 (0x43)	`timeticks`
68 (0x44)	`opaque`
70 (0x46)	`counter64`
128 (0x80)	`no_such_object`
129 (0x81)	`no_such_instance`
130 (0x82)	`end_of_mib_view`
48 (0x30)	`sequence`	`items`

`body` › `ip_address`

Field	Type	Default	Auto	Description
`address`	`ipv4`

`body` › `sequence`

Field	Type	Default	Auto	Description
`items`	`tlv` — rest of the PDU

`body` › `sequence` › `items`

Type 8 bits, length 8 bits.
The length counts the value only.
Unknown types are kept as raw value octets.

Type	Name	Value fields	Description
2 (0x02)	`integer`
4 (0x04)	`octet_string`
5 (0x05)	`null`
6 (0x06)	`object_identifier`
64 (0x40)	`ip_address`	`address`
65 (0x41)	`counter32`
66 (0x42)	`gauge32`
67 (0x43)	`timeticks`
68 (0x44)	`opaque`
70 (0x46)	`counter64`
128 (0x80)	`no_such_object`
129 (0x81)	`no_such_instance`
130 (0x82)	`end_of_mib_view`
48 (0x30)	`sequence`	`items`

`body` › `sequence` › `items` › `ip_address`

Field	Type	Default	Auto	Description
`address`	`ipv4`

`body` › `sequence` › `items` › `sequence`

Field	Type	Default	Auto	Description
`items`	`tlv` — rest of the PDU

body › sequence › items › sequence › items

Type 8 bits, length 8 bits.
The length counts the value only.
Unknown types are kept as raw value octets.

Type	Name	Value fields	Description
2 (0x02)	`integer`
4 (0x04)	`octet_string`
5 (0x05)	`null`
6 (0x06)	`object_identifier`
64 (0x40)	`ip_address`	`address`
65 (0x41)	`counter32`
66 (0x42)	`gauge32`
67 (0x43)	`timeticks`
68 (0x44)	`opaque`
70 (0x46)	`counter64`
128 (0x80)	`no_such_object`
129 (0x81)	`no_such_instance`
130 (0x82)	`end_of_mib_view`

body › sequence › items › sequence › items › ip_address

Field	Type	Default	Auto	Description
`address`	`ipv4`

Constraints

Level	Rule
warning	`pdu_type` = 164
warning	header and payload at most 129 octets

Sample templates

snmp-trap-v1 — templates/protocols/app/snmp-trap-v1.wpg.yaml