OpenWrt 19.07.5, r11257-5090152ae3
 LiMe master development (master rev. d4b8732 20201210_2003)
From https://libremesh.org/docs/en_connecting_nodes.html

All the nodes are probably in the same collision domain, so you can use NMAP to discover the nodes in your network and their IPv4s.

nmap -sT -p 80 10.X.Y.0/24 --open

Here: nmap not found

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Regards
Juergen