nanog mailing list archives
Re: Cloudflare reverse DNS SERVFAIL, normal?
From: Owen DeLong <owen () delong com>
Date: Tue, 30 Aug 2016 16:43:59 -0700
On Aug 30, 2016, at 15:50 , Valdis.Kletnieks () vt edu wrote: On Tue, 30 Aug 2016 14:39:10 -0700, Owen DeLong said:I run a pair of nameservers. Let’s call them ns1.company.com and ns2.company.comSomeone registers example.com and points NS records in the COM zone at my nameservers.I would have expected that the resulting NXDOMAIN replies from ns1 and ns2 would usually make this a self-correcting problem.
You don’t get NXDOMAIN when a nameserver gets a request for a zone it doesn’t serve. You either get SERVFAIL or you get NS records back as a referral.
Are there actually people who do this misconfiguration on a zone big enough for the traffic to matter, and leave it that way for very long before they clue in that things aren't working right? I'd think that if somebody points billy-bobs-bait-tackle-and-internet.com at you, it might take you quite some time to notice - and if somebody whoopsies and points ebay.com's NS records at you, the resulting disfunction would be noticed fairly soon….
Depends on your definition of “matter”. Also, misconfiguring one important zone doesn’t necessarily generate significantly more traffic than generating a whole lot of unimportant ones. Especially if you misconfigure zones in ip6.arpa or in-addr.arpa as was the case at the beginning of this topic.
(Miscreants who do this intentionally are, of course, a totally different kettle of fish, and need to be dealt with as micreants....)
Yep, though one has to wonder why they would bother. Owen
Current thread:
- Re: Cloudflare reverse DNS SERVFAIL, normal?, (continued)
- Re: Cloudflare reverse DNS SERVFAIL, normal? David (Aug 29)
- Re: Cloudflare reverse DNS SERVFAIL, normal? Mark Andrews (Aug 29)
- Re: Cloudflare reverse DNS SERVFAIL, normal? Chris Adams (Aug 29)
- Re: Cloudflare reverse DNS SERVFAIL, normal? David (Aug 29)
- Re: Cloudflare reverse DNS SERVFAIL, normal? Mark Andrews (Aug 29)
- Re: Cloudflare reverse DNS SERVFAIL, normal? Owen DeLong (Aug 30)
- Re: Cloudflare reverse DNS SERVFAIL, normal? Mark Andrews (Aug 30)
- Re: Cloudflare reverse DNS SERVFAIL, normal? Owen DeLong (Aug 30)
- Re: Cloudflare reverse DNS SERVFAIL, normal? Mark Andrews (Aug 30)
- Re: Cloudflare reverse DNS SERVFAIL, normal? Chris Adams (Aug 29)
- Re: Cloudflare reverse DNS SERVFAIL, normal? Valdis . Kletnieks (Aug 30)
- Re: Cloudflare reverse DNS SERVFAIL, normal? Owen DeLong (Aug 30)
- Re: Cloudflare reverse DNS SERVFAIL, normal? Niels Bakker (Aug 31)
- Re: Cloudflare reverse DNS SERVFAIL, normal? Nigel Jones (Aug 31)