arp-scan is also an excellent "well crap, I plugged my RPi in, but I have no idea what its IP is" tool. Much faster than needing to log into your router or whip out an IP scanner.
(Of course, if I was smarter, I'd just give it a static local IP, but alas...)
Thanks :-) I enjoy writing the most when it is akin to a discord chat I'd have with a friend dumping on him something I find cool! I need to be mindful of too many exclamation marks tho!
This made me think of Scotty/tkined, a cool Tcl based network management tool I used many years ago. I thought that ARP scans were one of the discovery methods we used but I think I was mistaken, it was just ICMP broadcasts and SNMP.
I had some manually added entries that would conflict with the automatically generated one, and it seems in this case Mikrotik just doesn't add the new entry, so I'm guessing it operates on a first come first serve basis.
RouterOS now has add-dns-entries and add-dns-entries-suffix settings in the DHCP server!
Ah, leave it to Mikrotik to wait for 10 years before providing a solution to an incredibly demanded feature, and then half-ass it to the point where you'd rather it continued to not exist.
Still no equivalent to dnsmasq' ra-names, and even DHCPv6 AAAA support is pretty much DoA — DHCPv6 clients generally do not send FQDN options, and it does not seem to cross-query hostnames from the related DHCP server (like dnsmasq does).
Yes, ARP is not the right tool to introspect your network.
Unfortunately, most home networks use an ISP router that does not do DHCP/DNS properly. I set up dnsmasq as DHCP/DNS because it works properly (and I also need it to do VPN duties). I've seen some ISP routers show host names on their admin UI, though.
ARP is for dealing with MAC addresses. Unless you note them down, the only "information" they carry is a) there's a device using this MAC address b) the MAC address is in this manufacturer's range.
nemin | 5 hours ago
arp-scanis also an excellent "well crap, I plugged my RPi in, but I have no idea what its IP is" tool. Much faster than needing to log into your router or whip out an IP scanner.(Of course, if I was smarter, I'd just give it a static local IP, but alas...)
[OP] benj | 2 hours ago
hehe, I hear you!
nmapis way to slow for this, and what if my rpi firewal is blocking icmp? Then it digging into the router's DHCP leases... ugh!avm99963 | 7 hours ago
Loved the way you wrote the article, I enjoyed a lot reading it!
Even if I already knew about
arp-scan(it is awesome indeed!), I learnt a lot from the journey and the pointers to ARP spoofing + broadcast storms.Previously I used proprietary software (Fing) which apparently works using ARP as well.
[OP] benj | 6 hours ago
Thanks :-) I enjoy writing the most when it is akin to a discord chat I'd have with a friend dumping on him something I find cool! I need to be mindful of too many exclamation marks tho!
donio | 4 hours ago
This made me think of Scotty/tkined, a cool Tcl based network management tool I used many years ago. I thought that ARP scans were one of the discovery methods we used but I think I was mistaken, it was just ICMP broadcasts and SNMP.
I was surprised to discover however that Flightaware maintains an active fork: https://github.com/flightaware/scotty
gir | 8 hours ago
i noticed the mikrotik mac in your arp table, so here's another tip: automatic dns entries for all (dhcp) devices on your network. :)
[OP] benj | 7 hours ago
That article is a bit outdated now :-)
RouterOS now has
add-dns-entriesandadd-dns-entries-suffixsettings in the DHCP server!https://manual.mikrotik.com/docs/network-management/dhcp/server#dns-entries-for-clients
gir | 6 hours ago
Ohh, finally! Personally, not a fan of long ttls. And i wonder how they handle conflicting hostnames.
yorickpeterse | 6 hours ago
I had some manually added entries that would conflict with the automatically generated one, and it seems in this case Mikrotik just doesn't add the new entry, so I'm guessing it operates on a first come first serve basis.
intelfx | 5 hours ago
Ah, leave it to Mikrotik to wait for 10 years before providing a solution to an incredibly demanded feature, and then half-ass it to the point where you'd rather it continued to not exist.
Still no equivalent to dnsmasq'
ra-names, and even DHCPv6 AAAA support is pretty much DoA — DHCPv6 clients generally do not send FQDN options, and it does not seem to cross-query hostnames from the related DHCP server (like dnsmasq does).koala | 6 hours ago
Yes, ARP is not the right tool to introspect your network.
Unfortunately, most home networks use an ISP router that does not do DHCP/DNS properly. I set up dnsmasq as DHCP/DNS because it works properly (and I also need it to do VPN duties). I've seen some ISP routers show host names on their admin UI, though.
ARP is for dealing with MAC addresses. Unless you note them down, the only "information" they carry is a) there's a device using this MAC address b) the MAC address is in this manufacturer's range.