Can't figure out this I.P. situation take a look

[montybdd12pack]

Hi. I am using comcast cable for internet. I am using a netgear mr314 router w/ address 10.0.0.1 By chance last night I was using tracert to check a site and found that after the first hop to 10.0.0.1 (router) there are 3 private range addresses that are hit before the first comcast i.p. address is hit. I removed the router and connected my laptop directly to the cable modem (surfboard 4200 using ethernet not usb). I still get the 3 private i.p. hops before the first comcast hop. I am puzzled by this. Either the cable modem has been hijacked or comcast is changing things around. Note: the assigned i.p. from the modem to the laptop is in the 68.x.x.x range.


The addresses go like this:

10.0.0.1 my router
10.92.0.1 private
172.30.59.17 private
172.30.59.58 private
68.57.192.50 comcast dns I believe



Any help to explain this would be greatly appreciated.

I can post a pic of the tracert if needed.

 

[ScottMac]

Likely as not, Comcast is using the RFC1918 addresses on their network.

It would keep users from setting up their own servers (per TOS), for example and give them some additional lattitude in setting up their address heirarchy (like it would for any large network).

They appear to be NATing. No big deal.


What's the WAN address of your router? If it's a 10.X.X.X address, then that's what they're doing.

FWIW

Scott

 

[SpunkyJones]

That would most likely just be Comcasts internal network that your hitting before you get to the outside world.

 

[montybdd12pack]

I get a wan address in the 68.58.x.x range. I can ping to my brothers dsl in idaho but his ping to me times out after hitting one of the comcast servers. The reason this is so strange is that this is a recent occurance. I will check with comcast but sometimes its hard to get someone who knows what they are talking about.

Thanks

 

[dexter333]

Originally posted by: ScottMac
Likely as not, Comcast is using the RFC1918 addresses on their network.

It would keep users from setting up their own servers (per TOS), for example....

1. 10.111.128.1 0% 1 1 9 9 9 9
2. 68.6.9.154 0% 1 1 10 10 10 10
3. fed1sysc01-gex0810.sd.sd.cox.net 0% 1 1 9 9 9 9
4. 68.6.8.194 0% 1 1 10 10 10 10
5. fed1bbrc02-pos0203.rd.sd.cox.net 0% 1 1 11 11 11 11
6. mtc3bbrc01-pos0103.rd.ok.cox.net 0% 1 1 184 184 184 184
7. 68.1.0.101 0% 1 1 151 151 151 151
8. lkhnbbrc01-pos0200.rd.at.cox.net 0% 1 1 236 236 236 236
9. lkhnbbrc02-pos0100.rd.at.cox.net 0% 1 1 73 73 73 73
10. ashbbbrj01-pos030000.r2.as.cox.net 0% 1 1 87 87 87 87
11. 206.223.137.37 0% 1 1 92 92 92 92
12. 66.117.32.65 0% 1 1 101 101 101 101
13. 66.117.35.18 0% 1 1 110 110 110 110
14. ???

I have no problems whatsoever running any sort of servers on my home cable connection aside from a select few ports Cox blocks.

 

[ScottMac]

I believe your traceroute is showing that you are doing the NAT, not Comcast.

The point was that _if_ Comcast was NATing the OP's connection ... then, in order to connect to that user's server behind the Comcast gateway, Comcast would have to specifically map an address or port aimed at that user's server (not likely).

In the case of Comcast providing a public address to your WAN port; you do your own NAT mapping, port translation, forwarding, etc ...

The traceroute provided is showing the first couple hops as private addresses. If Comcast isn't doing the NAT, then the OP or the people he's sharing the cable service from are (assuming the addresses provided are from a valid traceroute).

FWIW

Scott