"Fernando Ronci" <fernandoro***@hotmail.com> wrote in message
news:Occ%2337I2JHA.1380@TK2MSFTNGP05.phx.gbl...
> Hi,
>
> Generally speaking, what does it mean when the last lines of a tracert
> output are the same? I'm troubleshooting a network issue and found that
> when I do a 'tracert' to a destination address (being 'destination' any
> host inside the network I'm troubleshooting) the last five lines are
> repeated. For example, suppose aaa.bbb.ccc.ddd is the IP address of the
> destination host, then if I perform a tracert from a host just one hop
> away I get:
> tracert -d aaa.bbb.ccc.ddd gives:
>
> TEST #1:
> ======
> Tracing route to aaa.bbb.ccc.ddd over a maximum of 30 hops
>
>  1    23 ms    23 ms    23 ms  200.3.60.11
>  2    28 ms    23 ms    23 ms  aaa.bbb.ccc.ddd
>  3    29 ms    35 ms    35 ms  aaa.bbb.ccc.ddd
>  4     *        *        *     Request timed out.
>  5    29 ms    35 ms    35 ms  aaa.bbb.ccc.ddd
>  6    30 ms    35 ms    35 ms  aaa.bbb.ccc.ddd
>
> Trace complete.
>
> Or from the other side of the world:
> TEST #2:
> ======
> [preceding hops trimmed for brevity]
> 10 81 ms 81 ms 81 ms 154.54.25.238
> 11 102 ms 99 ms 99 ms 154.54.24.154
> 12 113 ms 107 ms 117 ms 154.54.3.26
> 13 112 ms 112 ms 118 ms 154.54.2.154
> 14 109 ms 109 ms 110 ms 154.54.10.102
> 15 * * * Timeout
> 16 * * * Timeout
> 17 255 ms 257 ms 258 ms aaa.bbb.ccc.ddd
> 18 255 ms 256 ms 256 ms aaa.bbb.ccc.ddd
> 19 255 ms 255 ms 255 ms aaa.bbb.ccc.ddd
> 20 257 ms 256 ms 256 ms aaa.bbb.ccc.ddd
> 21 257 ms 256 ms 256 ms aaa.bbb.ccc.ddd
>
>
> As can be seen from both tests, the problem is not dependent on the
> host/network initiating the 'tracert'.
>
> A couple more things:
> 1) When the tracert is performed against my gateway (owned and configured
> by the ISP) the same problem happens. This rules out a misconfiguration on
> my part.
> 2) aaa.bbb.ccc.ddd belongs to a small subnet whose mask is:
> 255.255.255.248 ( maybe the masks are messed up somewhere outside of my
> scope? )
>
> My questions: Why does this happen? What can be so badly configured (and
> where) such that the destination has to be probed five times before
> 'tracert' acknowledges that the host has been reached? How do I identify
> the misbehaving device?
>
> Thanks.
> Fernando
>
>

"Jack-MVP" <j***@discussgroups.com> wrote in message
news:eshWfVJ2JHA.5276@TK2MSFTNGP04.phx.gbl...
> Hi
> You Tracert through the Internet into a LAN with Router, Firewalls, and
> close ports?
> Jack (MS, MVP-Networking)

"Fernando Ronci" <fernandoro***@hotmail.com> wrote in message
news:uErkFlJ2JHA.1644@TK2MSFTNGP02.phx.gbl...
> Thanks Jack,
>
> Router --> Yes
> Firewall and closed ports --> No (AFAIK)
>
> As you can see this is a very very simple setup. (security hardening will
> come at a later stage)
> Fernando
>
> "Jack-MVP" <j***@discussgroups.com> wrote in message
> news:eshWfVJ2JHA.5276@TK2MSFTNGP04.phx.gbl...
>> Hi
>> You Tracert through the Internet into a LAN with Router, Firewalls, and
>> close ports?
>> Jack (MS, MVP-Networking)
>
>

"Jack [MVP-Networking]" <j***@discussiongroup.com> wrote in message
news:uPkJ0YP2JHA.3544@TK2MSFTNGP04.phx.gbl...
> Hi
> A Router acts like a NAT firewall and close all the ports to traffic that
> was not generated from inside the Network.
> I.e. running a tracert from the outside without special port forwarding
> configuration would not work.
> Jack (MS, MVP-Networking).
>

"Fernando Ronci" <fernandoro***@hotmail.com> wrote in message
news:ea9SUMV2JHA.3676@TK2MSFTNGP06.phx.gbl...
> Thanks for following up Jack,
>
> On a clean pipe with no firewalls, no NAT, no filters, all ports open,
> where you have full visibility to/from the public Internet, there
> shouldn't be any issues with tracert (ICMP).
> In this context, I cannot understand why the last hop appears five times
> in every tracert output targeted at hosts within my subnet. My guess is
> that the routes are messed up on my perimeter network, but I don't know
> how to prove it so that I call my ISP with a solid argument. Any insights?
>
> Thanks.
> Fernando
>
>
> "Jack [MVP-Networking]" <j***@discussiongroup.com> wrote in message
> news:uPkJ0YP2JHA.3544@TK2MSFTNGP04.phx.gbl...
>> Hi
>> A Router acts like a NAT firewall and close all the ports to traffic that
>> was not generated from inside the Network.
>> I.e. running a tracert from the outside without special port forwarding
>> configuration would not work.
>> Jack (MS, MVP-Networking).
>>
>
>