InformationThe administrator can configure SNMP to the interfaces source IP address for notifications
By using a source interface the administrator can ensure that the source IP of SNMP traps does not change as the network topology changes. For instance, if a link fails or is reconfigured, and a different IP address is now topologically 'closer' to the SNMP trap server. There are a few typical candidates for an SNMP source IP address:
A loopback address, as loopbacks are always up, and can then route over any transit interface.
The MGMT 0 address, as that provides an out-of-band path to the SNMP server. SNMP traffic volume will not affect traffic volumes, and SNMP cannot be 'starved' for bandwidth by production traffic. If the entire path is out-of-band, this also provides excellent protection from eavesdropping by malicious actors that may be on the 'production data side' of the switch.
A combination of the two (this is less common) - for instance a loopback address in the management VRF
Solutionswitch(config)# snmp-server host 188.8.131.52 source-interface mgmt 0
switch(config)# snmp-server host 184.108.40.206 source-interface loopback 0
SNMP Server traps or informs:
switch(config)# snmp-server source-interface traps loopback 0
switch(config)# snmp-server source-interface informs loopback 0
switch(config)# snmp-server source-interface traps mgmt 0
switch(config)# snmp-server source-interface informs mgmt 0
Not configured. By default SNMP traffic is sourced from the layer 3 interface that is topologically closest to the configured SNMP server