Nagios Support Forum

Is there an easy way when monitoring a switch bandwidth to see the ip address's of the machines using the bandwidth on each port?

Depends on the switch, there is netflow provided by some switches and on others you'd need to add a rule(a firewall rule perhaps) and monitor the BW for the rule(s).

Generally no as this is a limitation of the switch being layer 2 devices, so you might be able to monitor by MAC address only... Though the point of a layer 2 device VS a layer 3 devices is simplistic design and this feature obviously takes away from that.

So is there no way to check via arp to translate the mac address into an ip address? then possibly compare the ip address with dns to produce a specific computer name? do you think this is possible?

Could you rephrase your inquiry, we might be talking about different things.

1. Getting per computer bandwidth measurements for port A.
Not possible unless the switch supports rules and the bandwidth of a rule can be monitored.
2. Getting a list of the computers sharing port A to display in the interface.
Possible if the switch exposes it's frame routing table(there should be SNMP MIBs for this), but simpler to do this manually.

These are more likely to work on a layer 3 switch.

jladd wrote:So is there no way to check via arp to translate the mac address into an ip address? then possibly compare the ip address with dns to produce a specific computer name? do you think this is possible?

I did just say that would defiantly be the limiting factor for a layer 2 switch, assuming it had rules and you can monitor how much data matched the rule.