RE: Pinging routers for network status

["Matt Levine" <mlevine () efront com>]

No, we don't actually perform a dns request, as that wouldn't be measuring
the network latency, we simply start a timer, wait for the tcp connection to
negotiate, and stop the timer.  The connection is then closed.  Currently we
do this every 2 minutes, which shouldn't be perceived as an attack of any
kind by a large nameserver, or at least no more so then sending icmp echo's
to their routers :)


Matt

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Matt Levine, CTO <mlevine () efront com>
eFront Media, Inc. - http://www.efront.com
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-----Original Message-----
From: owner-nanog () merit edu [mailto:owner-nanog () merit edu]On Behalf Of
Miguel A.L. Paraz
Sent: Monday, December 18, 2000 1:38 AM
To: nanog () merit edu
Subject: Re: Pinging routers for network status



On Mon, Dec 18, 2000 at 01:12:17AM -0800, Matt Levine wrote:
> Well, although there's no entirely fool-proof way, We've found a better
way
> of monitoring "real" outages/issues is to monitor the time required to
setup
> a tcp connection to some "trusted" machines.   For example, in our VA
> datacenter we monitor the time required to setup a connection with tier1
> providers (UU,BBN,DIGEX for example) nameservers (on port 53)..  We've
found
> it slightly more reliable than ICMP reqs, especially since when routers
get
> busy, it shows as degradation vs. outage.

How does your "DNS ping" work, do you just open and close a TCP connection?
Or make actual requests?   Like, "dig soa provider.net @ns.provider.net".
But perhaps if everyone starts doing this to the same box, it could be seen
as DoS?


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