1

You can use ping to measure RTT between you and an IP host and thereby confirm connectivity. Is there an equivalent that can be used on L2/Ethernet with MAC addresses?

i.e. l2ping AA:BB:CC:DD:EE:FF

(I know that l2ping is an actual utility for Bluetooth L2; just looking for an Ethernet equivalent)

2
  • Many systems have a utility call "arping" which uses ARP. But there's nothing inherent in ethernet for end-to-end loopback. (there is a loopback frame, but that's just between link partners.)
    – Ricky
    Sep 22 at 18:38
  • Thank you very much, those sounds like very useful debugging tools. Is there a utility which implements sending and measuring loopback frames?
    – Atemu
    Sep 22 at 18:57
0

No, there's no such thing for Ethernet. Other layer-2 protocols might have such implementations. Technically, it's not an impossibility, most protocols just lack the mechanism/service.

You should note that the common IP ping utility is not a very precise tool for measuring RTT either: ping uses ICMP echo requests and ICMP processing has a very low priority, at least on network appliances. Accordingly, ping can only provide an upper bound for the actual RTT.

1

There was a level 2 ping equivalent in the original Ethernet 2 specification. It was the Loopback option in the Ethernet Configuration Testing Protocol, and was mandatory, However, it was not adopted when the IEEE standardized Ethernet as 802.3.

DEC supported it on their machines, and it was sometimes useful to check network connectivity to systems where the network stack was not configured. Later, ectpping was ported to Linux.

However, these days it's a historical footnote, so the practical answer is no.

1
  • A (physical) loopback is different from an echo service. A loopback tests a local transmitter and receiver in combination, without any cabling. An echo service tests that over the whole path between two nodes.
    – Zac67
    Sep 30 at 10:20
-1

No. In Layer 2 is not possible to send a frame to another device asking for a reply. Layer 2 is able to transmit frames from point A to point B but to ask for a reply it is necessary a higher-level protocol.

3
  • i would not use layer2 in general. layer2 can be reliable and have service discovery in it.
    – Effie
    Sep 30 at 8:17
  • It's not impossible at all, just very uncommon.
    – Zac67
    Sep 30 at 10:17
  • well, quite a number of wireless layer2s are reliable, and given the number of wireless devices nowdays, i don't think "very uncommon" actually applies. [i believe send a frame and ask for an ACK qualifies as send a frame and ask for reply]
    – Effie
    Sep 30 at 10:42

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.