On Sun, 06 May 2007 20:27:20 -0400 Joe Maimon <jmaimon@ttec.com> wrote:
Lincoln Dale wrote:
traceroute/tcptraceroute show packet loss and MUCH higher rtt than the corresponding direct pings on the reported hop entries.
the vast majority of routers on the internet respond very differently to
Is this some sort of massaging or plain just "faking it"? Or is such things merely net-urban myth? traffic 'directed at them' as opposed to traffic 'routed through them'.
Thanks for your reply.
I did include icmp echo directly to each hop as a comparison.
Right, but from what you posted you didn't send 1500-byte packets. My reaction was the same as Lincoln's -- it smells like a Path MTU problem. To repeat -- ping and traceroute RTT from intermediate nodes is at best advisory, especially on timing. I should add -- DSL lines often use PPPoE, which in turn cuts the effective MTU available for user packets. If the PMTUD ICMP packets don't get through -- and they often don't, because of misconfigured firewalls -- you're likely to see problems like this. --Steve Bellovin, http://www.cs.columbia.edu/~smb