10.x.x.x IP address found in traceroute

From what I've read, 10.0.0.0 - 10.255.255.255 is a private address space. So I ran a tracert over the internet and I saw an address 10.15.25.98. How is that possible? Thanks in advance!

Tracert Log:

1   192.168.1.1 1ms None    
2   ----    Timeout n/a 
3   10.15.25.110    13ms    None    
4   10.15.8.49      16ms    None    
5   65.46.186.97    11ms    ip65-46-186-97.z186 
6   216.156.0.185   24ms    vb1730.rar3.chicago 
7   ----    Timeout n/a 
8   216.1.123.54    48ms    None    
9   66.109.6.154    51ms    ae-1-0.cr0.chi30.tb 
10  107.14.19.61    62ms    None    
11  65.29.1.35      58ms    be1.clmkohpe02r.mid

pkSML

Posted 2014-02-04T22:30:05.957

Reputation: 352

Please share the details of your tracert, you can anonymize where necessary. – MikeDawg – 2014-02-04T22:35:22.913

It's in CSV format.[code]1,192.168.1.1,1ms,None,---- 2,----,Timeout,n/a,---- 3,10.15.25.110,13ms,None,---- 4,10.15.8.49,16ms,None,---- 5,65.46.186.97,11ms,ip65-46-186-97.z186,---- 6,216.156.0.185,24ms,vb1730.rar3.chicago,---- 7,----,Timeout,n/a,---- 8,216.1.123.54,48ms,None,---- 9,66.109.6.154,51ms,ae-1-0.cr0.chi30.tb,---- 10,107.14.19.61,62ms,None,---- 11,65.29.1.35,58ms,be1.clmkohpe02r.mid,----[/code] ... Sorry, can't get this to display right... (I'm a new user) – pkSML – 2014-02-04T22:37:39.470

Answers

Not every ip address on your tracert has to be a public IP.

It might be a router or server on one of the internal nodes of an ISP that you went through on the way to your destination.

Alex McKenzie

Posted 2014-02-04T22:30:05.957

Reputation: 1 559

Just beat me to it! Good, simple and quick answer :) +1 – xstnc – 2014-02-04T22:40:09.073

Your ISP is likely using Carrier Grade NAT.

You can verify this by looking in your home router and checking what the WAN IP address is that you get from your ISP. You've likely been assigned an IP in the 10.0.0.0/8 range as well. If that is the case then those suspicious hops are just the routers that are used to get from your machine to the edge of your ISPs network.

heavyd

Posted 2014-02-04T22:30:05.957

Reputation: 54 755

The hops can still be the routers even if it is not the case that the external IP address of the customer-premises equipment is in a non-publicly-routable range. – JdeBP – 2014-02-05T10:51:48.713

My public IP address is a routable address. But your link gives me something more to learn ;) – pkSML – 2014-02-05T12:14:22.837

-1

If you refer to RFC1918 http://www.faqs.org/rfcs/rfc1918.html it states:

3. Private Address Space

   The Internet Assigned Numbers Authority (IANA) has reserved the
   following three blocks of the IP address space for private internets:

     10.0.0.0        -   10.255.255.255  (10/8 prefix)
     172.16.0.0      -   172.31.255.255  (172.16/12 prefix)
     192.168.0.0     -   192.168.255.255 (192.168/16 prefix)

10.0.0.0/8 is a private IP address.

MikeDawg

Posted 2014-02-04T22:30:05.957

Reputation: 137

... which the questioner said in the question. The actual question, which you've not answered at all, was how. – JdeBP – 2014-02-05T10:43:07.153