North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Recommendation of Tools
On 4 dec 2008, at 14.05, Pekka Savola wrote: On Wed, 3 Dec 2008, Anders Lindbäck wrote: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.. According to the 0.75 sorcecode ICMP is still the default prot used, and the definition of MTR from bitwizards homepage disagress with you: "mtr combines the functionality of the 'traceroute' and 'ping' programs in a single network diagnostic tool. As mtr starts, it investigates the network connection between the host mtr runs on and a user-specified destination host. After it determines the address of each network hop between the machines, it sends a sequence ICMP ECHO requests to each one to determine the quality of the link to each machine. As it does this, it prints running statistics about each machine. For a preview take a look at the screenshots." Even if you use UDP/TCP or whatever, the return packet will be ICMP and that will be ratelimited by any carrier worth there salt... 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.. According to the 12.4T refrence it is still set to 1 packet / 500ms as default, however changes where made to how you can controll this in 12.4(2)T. -- Pekka Savola "You each name yourselves king, yet the Netcore Oy kingdom bleeds." Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings ------------------------------ Anders Lindbäck [email protected]
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