tracerouteコマンドの動きについて ref: https://qiita.com/S-T/items/4b4815a408a2ad71a58a

file0.txt

950         for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
951                 u_int32_t lastaddr = 0;
952                 int gotlastaddr = 0;
953                 int got_there = 0;
954                 int unreachable = 0;
955                 int sentfirst = 0;
956                 int loss;
957 
958                 Printf("%2d ", ttl);
959                 for (probe = 0, loss = 0; probe < nprobes; ++probe) {
960                         register int cc;
961                         struct timeval t1, t2;
962                         register struct ip *ip;
963                         struct outdata outdata;