netmap is a small C program that maps network topology by running traceroutes to one or more targets simultaneously. It sends ICMP Echo probes (IPv4 and IPv6) with incrementing TTLs, merges the resulting paths into a single graph, collapses shared hops, and renders the tree to the terminal as it discovers each hop.

Requires root — raw ICMP and ICMPv6 sockets are needed to send probes and receive TTL-exceeded replies.

To build, run make. To trace one or more targets:

sudo ./netmap google.com cloudflare.com 1.1.1.1

Pass -m maxhops to cap the TTL search (default: 30). Up to 16 targets are accepted per run, and IPv4 and IPv6 targets can be mixed freely.