TCP/IP 详解 卷1 ch8 Traceroute

>> traceroute 135.252.34.158
traceroute to 135.252.34.158 (135.252.34.158), 30 hops max, 40 byte packets
1  135.252.129.1 (135.252.129.1)  0.202 ms  0.205 ms  0.227 ms
2  135.242.64.149 (135.242.64.149)  1.601 ms  1.929 ms  2.044 ms
3  135.242.64.182 (135.242.64.182)  3.748 ms  4.999 ms  5.242 ms
4  a.com (135.252.34.158)  0.259 ms  0.257 ms  0.559 ms

1. For each TTL value three datagrams are sent.

2. If no response is received within 5 seconds for any of the three datagrams, an asterisk is printed instead and the next datagram is sent.

3. ip.addr == 135.252.34.158 for the example

4. The destination UDP port starts at 33435 and is incremented by one each time a datagram is sent.

5. source routing