Odd traceroute issue, afflicts Mac not Windows PC

[Shivetya]

So if I do a trace route to 12.247.68.74 from my iMac it stalls hitting that IP address but the Windows PC next to it can do it just fine. This is part of the route to the Blizzard servers at 24.105.62.129; there are only blizzard servers beyond that 12.247 number which belongs to AT&T

Ideas of what/how OS X drops this? I can ping it, but not traceroute it.

ING 12.247.68.74 (12.247.68.74): 56 data bytes
64 bytes from 12.247.68.74: icmp_seq=0 ttl=58 time=15.600 ms
64 bytes from 12.247.68.74: icmp_seq=1 ttl=58 time=17.872 ms
64 bytes from 12.247.68.74: icmp_seq=2 ttl=58 time=20.484 ms
^C
--- 12.247.68.74 ping statistics ---
3 packets transmitted, 3 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 15.600/17.985/20.484/1.995 ms
iMac:~ WhiteStar$ ping -a 12.247.68.74
PING 12.247.68.74 (12.247.68.74): 56 data bytes
64 bytes from 12.247.68.74: icmp_seq=0 ttl=58 time=10.379 ms
64 bytes from 12.247.68.74: icmp_seq=1 ttl=58 time=19.010 ms
64 bytes from 12.247.68.74: icmp_seq=2 ttl=58 time=14.371 ms
^C
--- 12.247.68.74 ping statistics ---
3 packets transmitted, 3 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 10.379/14.587/19.010/3.527 ms
iMac:~ WhiteStar$ traceroute 12.247.68.74
traceroute to 12.247.68.74 (12.247.68.74), 64 hops max, 52 byte packets
1 homeportal (192.168.1.254) 12.861 ms 3.335 ms 3.213 ms
2 107-128-92-1.lightspeed.tukrga.sbcglobal.net (107.128.92.1) 5.618 ms 6.458 ms 6.651 ms
3 107.212.168.126 (107.212.168.126) 8.912 ms 9.503 ms 8.950 ms
4 12.83.82.209 (12.83.82.209) 11.895 ms 11.315 ms 11.957 ms
5 gar18.attga.ip.att.net (12.122.96.89) 9.964 ms 10.499 ms 10.431 ms
6 * * *
7 * *

 

[2984839]

The Windows tracert utility defaults to using ICMP packets. On macOS, Linux, and BSD, traceroute defaults to UDP.

Try telling traceroute to use ICMP. Something like

traceroute -I 12.247.68.74

or whatever the ICMP flag is for traceroute on macOS.

As to why, some ISPs try to block traceroute to hide their topology while forwarding ICMP packets. They might drop any IP packets with expired TTL fields or refuse to decrement the TTL.