-----Original Message----- From: Richard A Steenbergen [mailto:ras@e-gerbil.net] Sent: Thursday, May 23, 2002 4:36 PM To: Mark Kent Cc: nanog@merit.edu Subject: Re: operational: icmp echo out of control?
Path latency doesn't change much, you can determine this with very few probes. Reachability does not need to be continuously probed, you can take cues from other data to decide if you need to re-probe.
I wonder if this can be used to profile a network for the sales droids? If one of your routers is being pinged continuously, this might be an indication they are using some sort of "Route Optimization/Failover" box. Especially if you ask them why they are pinging you on the order of 1-5pps and they can't really give an answer and don't turn it down. Sic-em! Sell them that managed BGP! For instance, the FatPipe box does this sort of thing "so you don't have to use BGP" to (sort of) multihome. Link failure is detected by loss of ping response. Failover (link and DNS) is under five seconds, so to prevent premature failover, ping often, and only failover if you take, say, three lost packets. The question for network operators is (just so this is kind of OT), is this kind of monitoring by the customer more of an annoyance, or a real item of operational concern? How would you react if you had a customer pinging the router on your side of his link (or farther upstream) that refused to limit the pings? James H. Smith II NNCDS NNCSE Professional Services - Network Engineer The Presidio Corporation