-2

Could someone please define the header for each of these columns?

macOS High Sierra v 10.13.3
Input: $ arp -a 

? (192.168.0.1) at b0:7f:b9:5a:d:a2 on en4 ifscope [ethernet]
? (192.168.0.10) at 0:18:4d:ff:ff:7 on en4 ifscope [ethernet]
? (192.168.0.15) at 9c:f3:87:ba:cd:80 on en4 ifscope [ethernet]
? (192.168.0.18) at 78:28:ca:14:db:f0 on en4 ifscope [ethernet]
? (192.168.0.24) at 38:c9:86:e:16:99 on en4 ifscope permanent [ethernet]
? (192.168.0.255) at ff:ff:ff:ff:ff:ff on en4 ifscope [ethernet]
? (224.0.0.251) at 1:0:5e:0:0:fb on en4 ifscope permanent [ethernet]
? (239.0.0.250) at 1:0:5e:0:0:fa on en4 ifscope permanent [ethernet]
? (239.192.152.143) at 1:0:5e:40:98:8f on en4 ifscope permanent [ethernet]
? (239.255.255.250) at 1:0:5e:7f:ff:fa on en4 ifscope permanent [ethernet]

Sincere thanks!

WolfeLogic
  • 49
  • 5

1 Answers1

4

? (239.255.255.250) at 1:0:5e:7f:ff:fa on en4 ifscope permanent [ethernet]
HOSTNAME | IP ADDRESS | MAC ADDRESS | INTERFACE | ROUTE COMMAND | ARP CACHE ENTRY STATE | HARDWARE TYPE

HOSTNAME: Apparently if the hostname can't be resolved, you get a ?
IP ADDRESS
MAC ADDRESS
INTERFACE or Iface: Ethernet Layer Tools, Appendix B.1.arp
ROUTE COMMAND: In this case, ifscope is used to bind a route to a specific interface. Routing flags.
ARP CACHE ENTRY STATE: In this case, permanent refers to a manually added address resolution.
HARDWARE TYPE or HWtype: Implicit reference from Ethernet Layer Tools, Appendix B.1.arp

Hope this helps someone down the line

WolfeLogic
  • 49
  • 5