I’ve only been lurking here for a couple of days and I hope this isn’t an inappropriate question for this group. No flames please if I shouldn’t have posted this (or for the double negative); a good stern warning will do just fine. 
The reason that I’m addressing this group is that I’m trying to get a perspective on provider policy and how decisions are made to do such things. If it’s not a conscious decision but the result of um er human error, what mechanisms are in place; or should be in place in order to correct such issues. So here it is:
I’m wondering if what I’m seeing in this trace route is normal provider behavior (I haven’t seen this happen before now). My provider is @home and when ever I do a trace route I get the following results:
1 211 ms 20 ms 20 ms cr1-hfc10.alsv1.occa.home.net [24.0.216.1]
2 10 ms 20 ms 40 ms r1-ge2-0.alsv1.occa.home.net [24.1.160.1]
3 180 ms 20 ms 30 ms 10.0.242.77
4 80 ms 50 ms 20 ms 10.0.242.73
5 30 ms 291 ms 20 ms c1-pos5-0.anhmca1.home.net [24.7.74.73]
… rest of results omitted for brevity.
As you can see, the third and fourth hop are advertising 10’s and I wouldn’t think a provider would want traffic passing through a private address space. Also, this is happening just as the traffic is leaving one facility and going to another (I don’t know if that means anything). If you’re interested alsv is Aliso Viejo and anhmca is Anaheim (both in Orange County, CA). I could be wrong but I’m fairly certain this has just been happening for the last few weeks. Maybe I never noticed before.
I’d call @home about it but I know I’d get the run around and it would take 5 hours on the phone for someone just to tell me it’s none of my business.
Regards,
Larry Diffey
P.S. NANOG Range Day should include pictures of various vendor equipment. Pick whatever is frustrating you at the moment.
On Tue, Jun 26, 2001 at 11:35:55PM -0700, Larry Diffey exclaimed:
3 180 ms 20 ms 30 ms 10.0.242.77
4 80 ms 50 ms 20 ms 10.0.242.73
As you can see, the third and fourth hop are advertising 10's and I wouldn't
think a provider would want traffic passing through a private address space.
ugh. you have just raised the skeleton of one of the top 3 most popular
religious wars in this forum. There is no consensus on this. I personally
think it's bad form, but as these addresses are unlikely to appear in anything
other than a traceroute, it's probably not hurting anything.
/me awaits the 1746 replies to come ...
I've only been lurking here for a couple of days and I hope this isn't
an inappropriate question for this group. No flames please if I
shouldn't have posted this (or for the double negative); a good stern
warning will do just fine. 
RFC1918 TROLL! lol. kidding. =)
I'm wondering if what I'm seeing in this trace route is normal provider
behavior (I haven't seen this happen before now).
<snip traceroute with 1918 addys>
Depends on the meaning of "normal". Check out
There are many, many other threads about this and related topics(NAT,
VPNs with 1918 addys, breaking traceoute with 1918 addys, etc.)
RFC1918 addys are sacred stomping ground.
@Home and Adelphia(atleast in VA) use 1918 addys internally. They
usually turn up between the modem and the distribution hub/headend(?).
Also, poke around at http://www.merit.edu/mail.archives/nanog/. Complete
archives of NANOG discussions from 1994.
-Gordo
On Tue, Jun 26, 2001 at 11:35:55PM -0700, Larry Diffey exclaimed:
3 180 ms 20 ms 30 ms 10.0.242.77
4 80 ms 50 ms 20 ms 10.0.242.73
As you can see, the third and fourth hop are advertising 10's and ?
wouldn't think a provider would want traffic passing through a private
address space.
ugh. you have just raised the skeleton of one of the top 3 most popular
religious wars in this forum. There is no consensus on this. I personally
think it's bad form, but as these addresses are unlikely to appear in
anything other than a traceroute, it's probably not hurting anything.
What if I were to tell you that some of these "so called private"
servers/machines, have telnet open to the @Home world ? Now that is a
problem. Its one thing to route these IP's among your equipment, its
another to not restrict customer access to them.
It also hoses PMTU Discovery if your router does RFC1918 ingress filtering
and one of the 10.x.x.x router addresses sends back a 'must fragment'.
But hey, we all knew that. 