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Public IP address

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New Poster

Public IP address

I would llike to know why I was assigned to a Public address from comcast beginning with 73.x.x.x to my modem but when I do a trace route from my machine to google.com, my next hop route from my machine

begins with 96.x.x.x.  I would think my next hop from my private address would be 73.x.x.x but it does not show 73.x at all. it shows that my next hop is 96.x.x.x.  I looked in my my router and modem and it specifies that the the gateway is 73.x.x.x.   I understand that the the wan port gets nat from my private IP 192.x.x.x to a public 73.x.x.x and the gateway is also on the same network of 73.x.x.1 but that gateway 73.x.x.1 should be on your boundary network device but the trace route doesnt show that.  it shows 96.x.x.x.  So is the 73.x.x.x masked? or please explain

 

Thanks

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Gold Problem Solver

Re: Public IP address

We rarely get answers to questions like this one. In my own case here in South Central PA, the first Comcast hop in traceroutes (Win 10 "tracert") is always 96.a.b.c, but my router reports an IP address and a default gateway in the 174.d.e.f range. I do not know why that is.

 

Better yet, traceroutes to the "first Comcast hop" and the gatway address IP look pretty much the same:

 


tracert -4 comcast.net
Tracing route to comcast.net [69.252.80.75] over a maximum of 30 hops:
1 15 ms 6 ms 6 ms router1 [192.168.1.1]
2 21 ms 20 ms 16 ms 96.a.b.c <-- first Comcast hop
^C

tracert -4 96.a.b.c <-- first Comcast hop Tracing route to 96.a.b.c over a maximum of 30 hops 1 22 ms 12 ms 12 ms router1 [192.168.1.1] 2 31 ms 20 ms 21 ms 96.a.b.c Trace complete. tracert -4 174.d.e.f <-- router default gateway Tracing route to c-174-d-e-f.hsd1.pa.comcast.net [174.d.e.f] over a maximum of 30 hops: 1 22 ms 12 ms 12 ms router1 [192.168.1.1] 2 33 ms 32 ms 22 ms c-174-d-e-f.hsd1.pa.comcast.net [174.d.e.f] Trace complete.

ETA:  I should note that some customers have reported that, for them, traceroute does report their gateway IP as the first Comcast hop. Why gateway IP = first hop IP for some but not for others, I do not know.

 

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Expert

Re: Public IP address

Public IP addys do not show up in traceroute outputs. Only the gateway addy does.



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