Hi,

traceroute or mtr showing only my router and final destination.
No other hops.
Why?

traceroute to yahoo.com (98.137.246.7), 30 hops max, 60 byte packets
1 192.168.0.1 (192.168.0.1) 1.005 ms 1.329 ms 1.620 ms
2 media-router-fp1.prod1.media.vip.gq1.yahoo.com (98.137.246.7) 180.807 ms 190.120 ms 190.305 ms

or:

traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets
1 192.168.0.1 (192.168.0.1) 1.155 ms 1.491 ms 1.786 ms
2 google-public-dns-a.google.com (8.8.8.8) 19.509 ms 19.702 ms 20.754 ms

or any other destination IP that answer to traceroute.
Only 2 hops.

the network working ok.

thanks.

The next router upstream has for some reason been configured to override the TTL (Time To Live) in the packet and substitute some new, default number. traceroute operates by setting a low TTL value (starting with 1) and successively incrementing that, thus causing each intermediate router to return a "TTL equals 0" ICMP response. That can't work if some router along the chain overrides that TTL.

If that next router is not under your control, there is nothing you can do.

Thanks rknichols.

But, which is the reason for such action (TTL modification) ?

I've read of it being implemented so that a router isn't explicitly identified eg avoiding ddos attacks.

Indeed. I have one router that I wish to have invisible in my own network, but I do that by having it increment TTL by 1. That prevents that router from ever seeing TTL==0, but allows traceroute to see the rest of the hops. You are apparently behind an internal network that someone wants to keep entirely hidden.

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