Find Out If My DNS Server Free From DNS Cache…

Q.How do I verify that my ISP or my own recursive resolvers are free from
[url=javascript:;]DNS[/url]
cache poisoning
[url=javascript:;]bug[/url]
that is promised full disclosure of the flaw by Dan on August 7 at the Black Hat conference? How do I test my dns server for DNS cache pollution or DNS Cache Poisoning bug?
A.DNS cache poisoning (also known as DNS cache pollution) is a maliciously created or unintended situation that provides data to a Domain Name Server that did not originate from authoritative DNS sources. It occur if DNS "spoofing attack" has been encountered. An attacker will send malicious data / non-secure data in response to a DNS query. For example dns query for www.cyberciti.biz can be redirected to www.example.com.
But how do I find out if my DNS server is open to such attack or not?
Visit Dan Kaminsky java script page to
check your DNS

You can also use following command dig command, enter:
$ dig +short @{name-server-ip} porttest.dns-oarc.net txt
$ dig +short @ns1.example.comporttest.dns-oarc.net txt
$ dig +short @208.67.222.222porttest.dns-oarc.net txt
Sample output:
z.y.x.w.v.u.t.s.r.q.p.o.n.m.l.k.j.i.h.g.f.e.d.c.b.a.pt.dns-oarc.net.
"208.67.222.222 isGOOD: 26 queries in 0.1 seconds from 26
[url=javascript:;]ports[/url]
with std dev 17746.18"
Another test,
$ dig +short @125.22.47.125 porttest.dns-oarc.net txt
Output:
z.y.x.w.v.u.t.s.r.q.p.o.n.m.l.k.j.i.h.g.f.e.d.c.b.a.pt.dns-oarc.net.
"125.22.47.139 isPOOR: 42 queries in 8.4 seconds from 1 ports with std dev 0.00"

本文来自ChinaUnix博客，如果查看原文请点：http://blog.chinaunix.net/u/4206/showart_1358904.html

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