From: Richard Foltz (ccie8339@rfoltz.com)
Date: Mon Aug 04 2003 - 12:08:00 GMT-3
traceroute doesnt use UDP. it uses ICMP. It send ICMP echos, with ever
increasing TTLs. i.e. the first one has a TTL of 1, next 2, next 3. Each
router int he path decrements the TTL, it it hits 0, the router sends back a
TTL expired. Thats how your computer knows the hops in between source and
destination. You need to make sure echo-request is allowed outbound, and
echo-reply, and ttl-expired are allowed inbound.
Richard Foltz, CCIE#8339 (R&S)
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of Tom
Young
Sent: Monday, August 04, 2003 9:49 AM
To: Ahmed Hassan
Cc: ccielab@groupstudy.com
Subject: RE: could ping but couldn't traceroute
Ahmed, Thanks alot for your reply,
Would you please tell me which udp port are used by
traceroute ?
Or the princinple of traceroute .
Thank you very much
--- Ahmed Hassan <ahmed_hassan@rayatelecom.net> $B$+$i$N(B
$B%a%C%;!<%8!'(B
> Hi tom,
> Trace route need Some UDP ports to be enabled
> best regards
>
> -----Original Message-----
> From: Tom Young [mailto:gitsyoung@yahoo.co.jp]
> Sent: Monday, August 04, 2003 11:28 AM
> To: ccielab@groupstudy.com
> Subject: could ping but couldn't traceroute
>
>
> Hi, group
>
> A very strange question, for a global address,
> I
> could ping it, but couldn't traceroute it. WHY ?
> I really confused.
>
> Thanks alot
>
> User Access Verification
>
> Password:
> office01>en
> Password:
> office01#trace
> office01#traceroute 210.178.28.2
>
> Type escape sequence to abort.
> Tracing the route to 210.158.218.2
>
> 1 202.248.86.129 0 msec 0 msec 4 msec
> 2 133.160.0.1 12 msec 8 msec 12 msec
> 3 133.160.239.34 8 msec 12 msec 8 msec
> 4 133.160.191.133 20 msec 20 msec 20 msec
> 5 133.160.224.51 24 msec 16 msec 12 msec
> 6 133.160.30.32 16 msec 20 msec 20 msec
> 7 133.160.240.254 16 msec 16 msec 16 msec
> 8 133.160.12.74 21 msec 16 msec 12 msec
> 9 210.171.224.49 12 msec 12 msec 12 msec
> 10 158.205.192.197 16 msec 12 msec 12 msec
> 11 158.205.192.150 16 msec 20 msec 16 msec
> 12 158.205.224.46 16 msec 16 msec 16 msec
> 13 158.205.235.69 16 msec 16 msec 16 msec
> 14 158.205.200.74 36 msec 36 msec 28 msec
> 15 * * *
> 16 * * *
> 17 * * *
> 18 * * *
> 19 * * *
> 20 * * *
> 21 * * *
> 22 * * *
> 23 * * *
> 24 * * *
> 25 * * *
> 26 * * *
> 27 * * *
> 28 * * *
> 29 * * *
> 30 * * *
> office01#ping 210.178.28.2
>
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 210.158.218.2,
> timeout
> is 2 seconds:
> !!!!!
> Success rate is 100 percent (5/5), round-trip
> min/avg/max
> = 12/14/16 ms
> office01#
>
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This archive was generated by hypermail 2.1.4 : Tue Sep 02 2003 - 18:53:52 GMT-3