nanog mailing list archives
Re: large organization nameservers sending icmp packets to dns servers.
From: Leigh Porter <leigh.porter () ukbroadband com>
Date: Mon, 06 Aug 2007 17:13:51 +0100
But why would they care where the nameserver is? Point 2 would seem to be a little stupid a thing to assume. Also, what happens if, at that moment, the ICMP packet is stuck in a queue for a few ms making the shortest route longer. -- Leigh Valdis.Kletnieks () vt edu wrote:
On Mon, 06 Aug 2007 11:53:15 EDT, Drew Weaver said:Is it a fairly normal practice for large companies such as Yahoo! And Mozilla to send icmp/ping packets to DNS servers? If so, why?Sounds like one of the global-scale load balancers - when you do a (presumably) recursive DNS lookup of one of their hosts, they'll ping the nameserver from several locations and see which one gets an answer the fastest. Yes, it's a semi-borkken strategy, because it assumes that: 1) ICMP is handled at the same rate as TCP/UDP packets in all the routers involved (so there's no danger of declaring a path "slow" when it really isn't, just becase a router slow-pathed ICMP). 2) That the actual requester of service is reasonably near net-wise to the server handling the end-user's recursive DNS lookup.
Current thread:
- RE: large organization nameservers sending icmp packets to dns servers., (continued)
- RE: large organization nameservers sending icmp packets to dns servers. David Schwartz (Aug 07)
- Re: large organization nameservers sending icmp packets to dns servers. Valdis . Kletnieks (Aug 07)
- Re: large organization nameservers sending icmp packets to dns servers. Tony Finch (Aug 08)
- RE: large organization nameservers sending icmp packets to dns servers. william(at)elan.net (Aug 08)
- Re: large organization nameservers sending icmp packets to dns servers. Patrick W. Gilmore (Aug 08)
- Re: large organization nameservers sending icmp packets to dns servers. Stephane Bortzmeyer (Aug 09)
- Re: large organization nameservers sending icmp packets to dns servers. Chris L. Morrow (Aug 10)
- Re: large organization nameservers sending icmp packets to dns servers. Duane Wessels (Aug 06)
- Re: large organization nameservers sending icmp packets to dns servers. Steve Atkins (Aug 06)
- Re: large organization nameservers sending icmp packets to dns servers. Valdis . Kletnieks (Aug 06)
- Re: large organization nameservers sending icmp packets to dns servers. Leigh Porter (Aug 06)
- Re: large organization nameservers sending icmp packets to dns servers. Owen DeLong (Aug 06)
- Message not available
- Re: large organization nameservers sending icmp packets to dns servers. Valdis . Kletnieks (Aug 06)
- Re: large organization nameservers sending icmp packets to dns servers. Patrick W. Gilmore (Aug 06)
- Re: large organization nameservers sending icmp packets to dns servers. Mark Andrews (Aug 09)