HP 2920 Switch - How Do You Find Out What Device Is Connected To A Port

[Fazza]

Using Putty/Telnet I have logged on to a HP 2920 Switch and I'd like to know if it's possible to work out what is connected to port 12 as whatever it is, is using a lot of bandwidth at the moment?

[computer_expert]

"sh arp" should list the arp table along with the IP/MAC/Connected port.

[Steve21]

You can do something for a MAC address, think it was "show mac A7" etc but then you'd have to delve into your DHCP and get the name or use command prompt etc to look it up

 

Steve

[Fazza]

Thanks for the replies.

 

If I enter show arp it doesnt show all the ports that are currently active only ports 1, 5 and 45. I know more are in use as if I browse to the IP address of the switch it shows what ports currently have a link light.

 

show mac-address 12 returns a MAC address that I cant find in DHCP.

[Steve21]

Could be something with a static IP then or another switch etc if it's uplinked.

 

if you got a client on the same IP range, run cmd prompt - arp -a and it'll list all macs and IPs linked to that.

 

Then browse the IP address in browser and see if something appears, could be nas/switch/server/printer etc

 

Steve

[glen_j]

if you have the mac address you could use the OUI to find the manufacturer. https://www.wireshark.org/tools/oui-lookup.html

[Fazza]

It's OK, I've worked it out - user error (arent most things)!

 

I used https://macvendors.com/ to find out the vendor and they tend to only make NICs for servers and I was adamant that we had no servers outside of the server room. That is apart from our Secondary SCDPM server and that's what it was!!!