SNMP stopped working on EX4300.

SNMP stopped working all of sudden on EX4300's.

When we verified the logs we find some interface related logs.

IFD stats of IPC subtype 56 is failing for xe-0/2/0 due to which stats requests are getting timeout in kernel and mib2d.

#define IF_MSG_GE_GET_INFO       56 /* Get G/E IFD info */

Aug 30 02:16:09 2024 EX4300 pfex: [EX-BCM PIC] ex_bcm_pic_eth_get_info: non EXPIC ifd 759, xe-0/2/0

Aug 30 02:16:09 2024 EX4300 pfex: IFFPC: 'IFD Ether get info' (opcode 56) failed

Aug 30 02:16:09 2024 EX4300 pfex:  ifd 759; Ether get info vector error (1000)

Aug 30 02:16:09 2024 EX4300 fpc0 [EX-BCM PIC] ex_bcm_pic_eth_get_info: non EXPIC ifd 759, xe-0/2/0

Aug 30 02:16:09 2024 EX4300 fpc0 IFFPC: 'IFD Ether get info' (opcode 56) failed 

Aug 30 02:16:09 2024 EX4300 fpc0  ifd 759; Ether get info vector error (1000)

Aug 30 02:16:19 2024 EX4300 pfex: [EX-BCM PIC] ex_bcm_pic_eth_get_info: non EXPIC ifd 759, xe-0/2/0

Aug 30 02:16:19 2024 EX4300 pfex: IFFPC: 'IFD Ether get info' (opcode 56) failed

Aug 30 02:16:19 2024 EX4300 pfex:  ifd 759; Ether get info vector error (1000)

This could happen with a non-Juniper optics being present on the interfaces.

We can try below workaround for uplink towards SNMP server.

Workaround suggested by SNMP team:
Add interface filter for those set of interfaces for which consistent kernel timeout is seen.
Sample config :
    'set snmp filter-interfaces interfaces "<uplink-port"'

In the above case customer did reboot the device solved the issue. This is another work around.