Hi folks
I'm trying to find a good explanation for the "Layer 3 visibility" switch in Net-SNMP. What does this actually do? I understand network layers, just not sure exactly how this applies here.
Thanks
Searched for that as well. The only hint I found [1] is the following:
"Layer 2 visibility covers physical connections: switch ports, VLANs, MAC addresses, and access point associations. Layer 3 visibility covers logical connections: IP addresses, routing paths, subnets, and gateway relationships. A tool that only provides Layer 3 maps cannot tell you which physical switch port a specific device is connected to. A tool that only provides Layer 2 maps cannot help you trace a routing problem."
[1] https://blog.domotz.com/all/network-visualization-tools/ - (search page for "Layer 3 Visibility")
This setting sets sysServices to 76 while the setting without Layer 3 visibility checked is 72. The sysServices parameter in snmpd.conf populates the matching OID telling a network management system which services the managed host runs.
https://oidref.com/1.3.6.1.2.1.1.7
72 means applications and end-to-end
76 means applications, end-to-end and IP
HTH,
Patrick