From: Brian (signal@xxxxxxxxxx)
Date: Mon Aug 06 2001 - 11:11:31 GMT-3
On Mon, 6 Aug 2001, Leonard @ iname.com wrote:
> Hello Guys,
>
> I found some traceroute that really bothers me and I don't know the
> answer. Would you kindly explain it to me ?
>
> traceroute from access.net.id to 202.156.227.140
> 14 172.20.6.11 (172.20.6.11) 466.566 ms 516.396 ms 464.313 ms
> 15 172.20.2.15 (172.20.2.15) 458.438 ms 464.12 ms 446.679 ms
> 16 172.20.15.2 (172.20.15.2) 465.278 ms 476.811 ms 570.675 ms
>
>
> If you check the entry 14-16 it is private address which is supposedly not
> routeable... and it goes at entry 17 to end-host of this ISP/cable... which
> is routeable address... Any idea ?
You can use RFC1918 space on point to point links, in which traffic just
transits thru, not sources or destinates directly too. Some argue this is
poor practice, but there are alot of people doing this nontheless. The
fact you got the packets back on the traceroute, means your probably not
blocking rfc1918 on your router (or your providers router) which you
probably want to block those networks. This wont effect reachability in
the above situation to the destination network, since the traffic is
coming from or going directly too the 172.20.x.x network. Using rfc1918
space can break things like Path MTU discovery.
Brian
>
> Thanks
> **Please read:http://www.groupstudy.com/list/posting.html
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