wake on lan - arp add 255.255.255.255 ff:ff:ff:ff:ff:ff (router)

21
2014-04
  • Sandro Dzneladze

    If I add arp entry in router config like this:

    arp add 255.255.255.255 ff:ff:ff:ff:ff:ff
    

    Open specific port:

    port: 1009 ip: 255.255.255.255
    

    Will it broadcast message to all connected devices?

    I'm sending wake on lan package.

    What if I add random IP like:

    arp add 192.168.1.15 ff:ff:ff:ff:ff:ff
    
    port: 1009 ip: 192.168.1.15
    

    Will it still broadcast to all network devices?

  • Answers
  • Sandro Dzneladze

    I found that arp add 255.255.255.255 ff:ff:ff:ff:ff:ff cannot be done, router gives error.

    arp add 192.168.1.15 ff:ff:ff:ff:ff:ff works fine for WOL functionality from WAN.


  • Related Question

    What happens when an ARP Request arrives to an Ethernet switch?
  • dario_ramos

    I remember reading somewhere that switches defined "data link layer broadcast domains": that is, data link broadcasts from one network connected to the switch are not forwarded to the others.

    If this is true, what happens when a host directly connected to a switch makes an ARP request? Does it go beyond the switch?


  • Related Answers
  • Spiff

    In the case of a basic switch -- that is, without getting into VLANs and so-called "layer-3 switches" -- the switch is NOT the edge of a broadcast domain. ARP broadcasts, like all broadcasts, are sent to all ports of the switch.

    You may have heard that switches separate collision domains, which is true, but is a separate concept from broadcast domains.