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.

netmap  2 target(s)  TTL 12/30  (2/2 reached)

[you]
\- 192.168.1.1  6.2 ms
   \- 10.66.67.1  143.1 ms
      \- 96.34.30.98  19.0 ms
         \- 96.34.16.78  15.0 ms
            \- 96.34.16.104  139.1 ms
               +- 96.34.1.20  171.2 ms
               |  \- 96.34.2.128  34.5 ms
               |     \- 96.34.3.9  146.5 ms
               |        \- 96.34.152.155  91.4 ms
               |           \- 192.178.249.225  186.6 ms
               |              \- 142.251.231.69  30.4 ms
               |                 \- 142.251.34.238  54.0 ms  -> google.com
               \- 96.34.2.153  171.2 ms
                  \- 96.34.3.65  34.5 ms
                     \- *
                        \- *
                           \- 13.104.183.145  181.3 ms
                              \- 150.171.27.10  33.7 ms  -> bing.com