Recommendation of Tools
list-only at dnz.se
Wed Dec 3 12:01:37 CST 2008
Mtr is even less usefull then that, in its default mode it does a
traceroute and then proceeds to ICMP Ping flood each IP in the list
generated by the traceroute, the result is usually completly useless
on WAN topologies due to asym-routing, ICMP node protections by
carriers and punting etc..
And using UDP will not really provide better results due to the same
thing, and IIRC Cisco from 12.0 has a standard setting of no more
then 1 ICMP Unreach per 500ms..
anders.lindback at dnz.se
On 3 dec 2008, at 12.00, Pekka Savola wrote:
> On Tue, 2 Dec 2008, Antonio Querubin wrote:
>> On Wed, 3 Dec 2008, Pekka Savola wrote:
>>> FWIW, Mtr measures latency/delay and loss based on ICMP messages
>>> back from the routers on path. As a result, in almost all
>>> cases, the real
>>> hop-by-hop latency of actual end-to-end data packets is better
>>> than it can
>> mtr has a recently added '-u' option to use UDP instead of ICMP
>> echo requests.
> But that doesn't change the gist of my message: it's still relying
> on ICMP ttl exceeded messages sent by the routers on the path to
> check the delays etc. As such it suffers from basically the same
> limitations as ICMP probing.
> Pekka Savola "You each name yourselves king, yet the
> Netcore Oy kingdom bleeds."
> Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings
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