Alright, this might appear a little confusing, all I know is that this problem is bugging me. We got ourselves a windows network with about 200 comps on it. We have a proxy server setup, it works fine, more or less. I was really confused about this before, until now. What I cant do is ping or trace SOME domains, like aol.com. Other ones I can do without a problem. Or if I use thgat visual trace program, it appears to go through with a high amount of packetloss(up to 90%). Here is my most recent traceroute, done with a max timeout of about 50000 to aol.com



Tracing route to aol.com [205.188.145.215]

over a maximum of 30 hops:



1 1 ms 2 ms 2 ms 10.94.38.1

2 57 ms 59 ms 101 ms 10.94.255.125

3 94 ms 97 ms 79 ms 10.94.8.55

4 66 ms 65 ms 59 ms 10.94.8.14

5 60 ms 60 ms 59 ms 63.124.135.1

6 316 ms 280 ms 228 ms 383.ATM1-0.GW7.MSP1.ALTER.NET [65.195.240.29]

7 398 ms 467 ms 781 ms 113.at-2-0-0.CL2.MSP1.ALTER.NET [152.63.69.102]

8 497 ms 490 ms 282 ms 0.so-1-0-0.TL2.CHI2.ALTER.NET [152.63.67.121]

9 307 ms 406 ms 670 ms 0.so-3-0-0.TL2.DCA6.ALTER.NET [152.63.19.170]

10 414 ms 451 ms 494 ms 0.so-4-0-0.XL2.IAD2.ALTER.NET [146.188.160.22]

11 635 ms 346 ms 561 ms POS6-0.ER5.IAD2.ALTER.NET [152.63.6.249]

12 313 ms 444 ms 425 ms pop4-dtc-P3-0.atdn.net [66.185.145.5]

13 443 ms 609 ms 539 ms bb1-dtc-P1-0.atdn.net [66.185.141.193]

14 398 ms 297 ms 295 ms pop1-dtc-P14-0.atdn.net [66.185.140.6]

15 535 ms 553 ms 489 ms 66.185.144.246

16 442 ms 416 ms 586 ms 172.18.126.74

17 172.18.126.78 reports: Destination net unreachable.


The last 172 address gives me the same error when I try to ping. Now 172.18 I thought at first was a private IP, but then I double checked and thats 172.16, so it must be another prob. I then whoised is on arin:

Search results for: 172.18.128.78

IANA (IANA-BBLK-RESERVED)
Internet Assigned Numbers Authority
4676 Admiralty Way, Suite 330
Marina del Rey, CA 90292-6695
US

Netname: IANA-BBLK-RESERVED
Netblock: 172.16.0.0 - 172.31.255.255

Coordinator:
Internet Corporation for Assigned Names and Numbers (IANA-ARIN) res-ip@iana.org
(310) 823-9358

Domain System inverse mapping provided by:

BLACKHOLE-1.IANA.ORG 192.0.32.18
BLACKHOLE-2.IANA.ORG 192.0.32.19

These blocks are reserved for special purposes.
Please see RFC 1918 for additional information.

Record last updated on 12-Oct-2001.
Database last updated on 6-Aug-2002 20:00:12 EDT.


Its the blackhole part that cought my eye. Now here is my final problem. When I go to the web, I can connect to aol.com without a problem.

Any ideas or more infor I need to give?

More than likely the IP address is in a modem dialup pool, so when you tracert or ping it you will probably not get the same computer each time, or you will get a dead route at the modempool, because the Ip address is waiting to get assigned to another caller. This can also be applied to high speed connections like cable modems or DSL that use DHCP.

I've seen private IPs, used on router on the internet before, a few routers at school are like that.

jkca, I think you misunderstood, what I am trying to ping, is aol.com that what happens when I try to ping or trace aol.com. Everytime I get to that ip, 172, it gets destination unreach

That IP address (172.18.128.78) is in one of the reserved blocks of IP addresses that isn't routable on the internet. You can use them to route within your own network though (much like you're using 10.x addresses within your own network, and that's what you're seeing here. It's reporting destination unreachable because it's filtering out your packets. Odds are AOL is not allowing specific packets through the router, it's not unusual at all, and there's nothing you can do about it, or need to do about it.

whoops didnt recognize the ICANN Ip as non routable, in general every router dumps these as soon as they get them, but it looks like the ip 66.185.144.246 is on AOL's transit network which is probably a L3 switch that is black holing certain packets that can be used for abuse, like flood pinging.

Your right, it is nothing. I was trying to setup a simple smtp server, and aol was never resolving, so I started on a spree to try and ping it, not paying attention to what I should of been looking at, the gateway. For some reason when setting up that computer, I set that gateway as the proxy server, instead of the router, so I just changed it and mail goes through fine.

Thanks bill