Network Engineering Stack Exchange is a question and answer site for network engineers. It only takes a minute to sign up.
Sign up to join this community
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)
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.
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.
I needed to verify connectivity between two layer2 endpoints. I used
arping -bI <device> <random-ip-not-on-the-network>
on one machine and
tcpdmp -i <device>
on the other end.
When I saw the ARP packets asking for the same random IP, I knew the interfaces were connected.
I don't know if this helps your scenario.
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.
