Customer has two EX4300-32F switches that are failing snmp polling from the snmp server and they also have three EX4300-32F switches that are snmp polling successful. The only difference in terms of configuration is the mgmt ip address, they are on the same subnet.

Customer is using SNMPv2.

Configuration:

set snmp location "OOB MGMT - DISTRIBUTION"

set snmp community 6mQ authorization read-only

set snmp community 6mQ routing-instance oob-mgmt clients x.x.x.x/24

set snmp trap-group 6mQ targets x.x.x.x

set snmp trap-group 6mQ routing-instance oob-mgmt

set snmp routing-instance-access

The snmp server is reachable through the routing-instance names OOB-MGMT.

Routing-instance configuration:

set routing-instances oob-mgmt routing-options static route 0.0.0.0/0 next-hop x.x.x.x

set routing-instances oob-mgmt instance-type virtual-router

set routing-instances oob-mgmt interface irb.101

set routing-options static route 0.0.0.0/0 next-table oob-mgmt.inet.0

Customer has the same configuration on the working and non-working EX4300 devices and all of them running of the same junos version.

During the session, we monitored the irb.101 interface (monitor traffic interface irb.101 no-resolve matching "port 161") on the problematic device.

However, we did not see any SNMP requests reaching the problematic device.

When we did the same for the working device, we observed the SNMP requests and confirmed that responses were going out.

No issues were found on the Juniper gear. Customer needs to check on their network side for further isolation.