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Some flavors of Cisco will drop inbound ICMP if they feel busy. When this happens, they do it silently and do not count errors, etc. I don't know if the NPE G2 is subject to this proclivity or not and I don't know how busy your router feels when you are doing this, but, the particularly regular pattern to the packet loss leads me to believe it is likely a CPU spike in the Cisco for some scheduled periodic task causing it to fail to process the inbound ICMP Echo Reply. (Remember, ICMP to the router is punted to the slow-path CPU) Owen On Oct 3, 2011, at 7:47 AM, Jeremy Lumby wrote: > This weekend I did some equipment upgrades, and while my BGP session re-established without a problem, I decided to ping the route servers to test connectivity. I found that both route servers exhibited about a 0.5% loss. I checked my interface counters, and I am not getting any errors, as well as I tried pinging a few other MICE members' routers and did not experience any loss. I am wondering if there is a speed/duplex mismatch between the route servers and the switch, or if there might be something running on the route servers that is intentionally dropping packets as some form of DoS protection. The following ping was performed from my Cisco 7206VXR that is directly connected to MICE via the gig port that is built into the G2 processor. > > 511Edge01#ping 69.147.218.1 repeat 1000 > > Type escape sequence to abort. > Sending 1000, 100-byte ICMP Echos to 69.147.218.1, timeout is 2 seconds: > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!! > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!! > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > !!!!!!!!!!!!!!!!!!!. > Success rate is 99 percent (995/1000), round-trip min/avg/max = 1/1/4 ms > > Jeremy Lumby > Minnesota VoIP > 9217 17th Ave S > Suite 216 > Bloomington, MN 55425 > Main: 612-355-7740 > Direct: 612-392-6814 > E-Fax: 952-873-7425 > [log in to unmask] > > ######################################################################## > > To unsubscribe from the MICE-DISCUSS list, click the following link: > http://lists.iphouse.net/cgi-bin/wa?SUBED1=MICE-DISCUSS&A=1 ######################################################################## To unsubscribe from the MICE-DISCUSS list, click the following link: http://lists.iphouse.net/cgi-bin/wa?SUBED1=MICE-DISCUSS&A=1