~$ tcptraceroute -n alt2.gmail-smtp-in.l.google.com 587
Selected device eth0, address 83.212.96.232, port 55374 for outgoing packets
Tracing the path to alt2.gmail-smtp-in.l.google.com (74.125.25.27) on TCP port 587 (submission), 30 hops max
 1  * * *
 2  83.212.96.2  0.943 ms  0.656 ms  0.686 ms
 3  62.217.100.32  0.858 ms  0.837 ms  0.917 ms
 4  62.40.124.89  0.988 ms  1.207 ms  0.990 ms
 5  62.40.112.153  27.698 ms  27.711 ms  27.854 ms
 6  62.40.112.33  35.046 ms  35.066 ms  35.065 ms
 7  62.40.112.161  42.852 ms  42.795 ms  42.886 ms
 8  * * *
 9  * * *
10  * * *
11  * * *
12  * * *
13  * * *
14  * * *
15  * * *
16  * * *
17  * * *
18  * * *
19  * * *
20  * * *
21  * * *
22  * * *
23  * * *
24  * * *
25  * * *
26  * * *
27  * * *
28  * * *
29  * * *
30  * * *
Destination not reached