nanog mailing list archives
Re: Recommendation of Tools
From: Anders Lindbäck <list-only () dnz se>
Date: Wed, 3 Dec 2008 19:01:37 +0100
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 Lindbäck anders.lindback () 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 heard 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 canreport.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
Current thread:
- Recommendation of Tools Lee, Steven (NSG Malaysia) (Dec 02)
- Re: Recommendation of Tools Andrew Mulholland (Dec 02)
- Re: Recommendation of Tools Pekka Savola (Dec 02)
- Re: Recommendation of Tools Tehno Mage (Dec 02)
- Re: Recommendation of Tools Antonio Querubin (Dec 03)
- Re: Recommendation of Tools Pekka Savola (Dec 03)
- Re: Recommendation of Tools Anders Lindbäck (Dec 03)
- RE: Recommendation of Tools Braun, Mike (Dec 03)
- Re: Recommendation of Tools Anders Lindbäck (Dec 03)
- Re: Recommendation of Tools Andre Gironda (Dec 03)
- Re: Recommendation of Tools Pekka Savola (Dec 04)
- Re: Recommendation of Tools Anders Lindbäck (Dec 04)
- Message not available
- Re: Recommendation of Tools Anders Lindbäck (Dec 04)
- Re: Recommendation of Tools Pekka Savola (Dec 02)
- Re: Recommendation of Tools Craig Holland (Dec 05)
- Re: Recommendation of Tools Andrew Mulholland (Dec 02)
- Re: Recommendation of Tools Hank Nussbacher (Dec 02)
- RE: Recommendation of Tools Christine Lane (Dec 03)