Domain Name System (DNS) is a service that provides the resolution of host names to IP addresses. Use the [tag:dns] tag when you are troubleshooting DNS issues, configuring a DNS resolver or server, or are trying to understand DNS's involvement in your situation.

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/usr/bin/host not picking up changes to /etc/hosts even after reboot

I have a Ubuntu Server 12.04 (amd64) machine on which, when I change /etc/hosts, the changes aren't picked up, even after a reboot. I am using /usr/bin/host to test, but none of the other programs ...
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Previously resolved hostnames

Is it possible to find previously resolved hostnames in linux? I have a host that I can currently not resolve, but I have resolved it earlier and would like to know which ip was resolved to.
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Dnsmasq white list for specific clients on network

I'd like to use dnsmasq to set up a white list for certain clients on my network. For instance, I'd like to have these rules for clients in the range 192.168.1.10 - 192.168.1.20: no-resolv ...
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Local DNS Server Refuses to Ask itself for DNS

I am running Debian 7 and have set up a DHCP and DNS server. Everything is working nicely, except for the server itself not following the DNS entries in BIND. The problem is that /etc/resolv.conf is ...
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Why do two Ubuntu systems in the same network behave differently in DNS resolution?

I have two systems, both running Ubuntu 12.04, which are within the same network (connected by hubs without routing logic). Both systems are configured quite similar, but not identical. In particular, ...
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Converting Webserver Logged IP Addresses to DNS

I'm trying to use a bash script to process a webserver log file and replace any IP's it finds with their corresponding DNS hostnames. An example entry of a single line from the log file is: ...
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getaddrinfo() from shell? [duplicate]

When you call ping name.domain, it goes through both /etc/hosts and the DNS resolver to obtain an IP. It could be an IP hard-coded in /etc/hosts, or it could be one from the DNS server. It does so by ...
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Debian cannot SSH to OS X by hostname (Windows OK)

I've seen some questions asking why xxx can't connect to MyMacName.local, which answer regarding Avahi as a requirement. I don't think I am in the same category as I can successfully connect to a ...
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Resolving pseudo domain name to private IP

Assume I have a VM running on OSX with private IP 10.0.0.1 which can be accessed from the host machine. I was wondering how can I map a pseudo domain, *.app.dev, to the private IP on my host machine ...
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How can I improve nscd's cache hit rate?

My Goal: Let nscd maintain a fairly large DNS cache in excess memory since I have it available. Description: I have a webserver that has a broadly dispersed but high-repeat user base. It has plenty ...
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DNSCrypt, Unbound and DNSSEC

I would like to have an encrypted DNS queries + a DNS Cache + Domain Name System Security Extensions (DNSSEC) . I used this bash script to install DNSCrypt and I choosed to use dnscrypt.eu servers : ...
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Split DNS (bind9), match-clients any doesn't work?

I've been fighting with this for the last few days. A few of my entries have external and internal IP's. My internal network is 10.0.0.0/8. When I nslookup pc1.clase.net internally it responds with ...
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Bind9 — How to find which programs are making which dns lookups?

Using bind9 on a laptop shows lots of nonsense domains when network connectivity is down: Oct 18 19:56:18 lap3 named[1536]: error (network unreachable) resolving './NS/IN': 128.63.2.53#53 Oct 18 ...
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How to allow recursion for only 1 zone?

Is it possible to allow recursion for a single zone in BIND 9.6?
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Two DNS servers, both incomplete

In my company we have 2 DNS servers: one for the internal hostnames and one for Internet. I tried to configure both in my Network Manager, who result in having the two DNS server IPs in my ...
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Configure Spamassassin to use URIBL and Google Public DNS

I use Google Public DNS servers on my mail server. However, URIBL and other spam blocking sites (which work over DNS) block major DNS sites such as Google Public DNS. I think if I run my own DNS ...
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Why is my computer trying to send ICMP type 3 to OpenDNS?

In my firewall logs I see lots of entries like this. IN= OUT=eth0 SRC=192.168.1.105 DST=208.67.220.220 LEN=148 TOS=0x00 PREC=0xC0 TTL=64 ID=55705 PROTO=ICMP TYPE=3 CODE=3 [SRC=208.67.220.220 ...
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/var/named/chroot/var/named: device is busy

When I restart the named service, it gives me this error: ./etc/init.d/named restart Stopping named: [ OK ] Starting named: Error in named ...
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Using DNSMasq for Local Hostname Resolution

I'm working on setting up a home intranet for me and my roommates. My idea is that we'll be able to store things like past utility bills in a place that's more accessible than a drawer in the kitchen ...
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dig vs nslookup

Why do the commands dig and nslookup sometimes print different results? ~$ dig facebook.com ; <<>> DiG 9.9.2-P1 <<>> facebook.com ;; global options: +cmd ;; Got answer: ;; ...
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Host domain name pointer in linux

I setup a Linux server and run a command, host wan ip in terminal and it shows ... domain name pointer mail.domain.com. How do i replace current new mail.domain.com to mail.newdomain.com?
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How can I use an ACL in BIND to forward requests per zone selectively?

I have some zones declared internally as forwards to another DNS, but there is a hefty amount of IP space we do not want to be forwarded in this manner for these zones. These forwards are for very ...
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Apache Request Hangs For 2 Minutes Exactly

I am experiencing some odd behavior with apache. I have requests that are hanging for exactly two minutes. The request could be one file one time, and then a completely different file another time. ...
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resolve the server hostname of a dnsmasq server with multiple subnets

I have a self-made Linux router running dnsmasq. It has two different NICs through which clients are connected; one of them has the subnet 192.168.1. and one the subnet 192.168.2.. My ...
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Does wildcarding significantly hurt BIND Performance?

I have enabled RPZ on my BIND 9.9.4 DNS server and I wanted to be able to wildcard some records in my RPZ zone, but I am afraid of the performance hit this might cause. Does anyone out there have some ...
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Debian machine makes repeated requests to DNS for <gateway_ip>.in-addr.arpa

I recently forwarded all my router logs to my Debian machine. I noticed a repeated entry in the router logs. The entry is: Sep 14 17:07:29 192.168.0.1 [Host 192.168.0.1] UDP 192.168.0.2,38048 --> ...
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Question about MX records and mail delivery?

Let's say, we have multiple mail servers in DNS records. If someone is sending a mail, the outgoing mail server will check the MX and contact the first server with the lowest cost. If this server ...
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Communication with MX records [closed]

I have a short question about the topic of MX records. Let's say, we have multiple mail servers in DNS records. If someone is sending a mail, the outgoing mail server will check the MX and contact ...
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How to set DNS resolver in Fedora using network-manager?

I want to try out Google public DNS. For this I need to change the nameserver address. I know it's in the file /etc/resolv.conf, but whenever I start network-manager, it overwrites the values in that ...
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Can't connect to to internet. Debian Wheezy, pinging DNS address works

I have booted Debian Wheezy from SD card on a Beaglebone Black board. Version: debian-wheezy-7.0.0-armhf-3.8.13-bone20.img.xz, from http://www.armhf.com/index.php/download/ I have set up my ...
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Process calling getaddrinfo() at boot gets permanently stuck with bad /etc/resolv.conf?

I'm running pianod, a Pandora client/server, on a Raspberry Pi with Arch Linux ARM. I have pianod set up to run as a service at boot. It starts up before the network stack, so getaddrinfo() fails. ...
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How to safely reverse dns lookup on ip in a shell script

I'm trying to find out how to take in a hostname and pop out an ip address (reverse dns lookup). I came up with this but I'm not too sure it's safe across different linux distros: nslookup $ip|grep ...
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Configurable DNS cache for Linux

What I need is to configure a Linux machine, so that when user of that machine goes to www.somesite.com he/she is redirected to, say, 127.0.0.1. What is the best way to achieve it?
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Unix: How to Test Ip Address is resolved to name

Unix: How to Test ip Address is resolved to name. I need to check whether ip address can be resolved to name using DNS entry via shell script. Code: DNS_Lookup() { LOOKUP=$(nslookup $1) ...
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What does my router need to act as a name server for my home network?

I am happily using an old PC as a router. Two network cards, Debian wheezy, NAT, ... everything just fine. My home network uses static IPs, which I am also happy with. However, every box on my home ...
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DNS zone fallback file

I have the following DNS zone(bind): zone "." IN { type master; file "named.root"; }; If this zone directive cannot resolve the address, how can I "fallback" to another file for the same ...
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Force local DNS resolution for external hosts

My Environment: *OS:* Angstrom Linux DNS: Bind Current Scenario: User connects to my private offline network. User tries to access google.com, and my box is on a private network therefore they ...
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When to use BIND vs internal DNS for Samba 4 backend

The docs say, "Bind as DNS backend is recommended, if you plan setup a complexer DNS setup, than the Samba 4 internal DNS currently made possible." What exactly is the threshold for "a complexer DNS ...
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How to host a website on personal computer

I want to start hosting my website at my own computer as well websites of my friends too (say mini hosting platform). I learned Debian, Bind9 and Apache for this purpose. On my system everything is ...
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How to attach my domain with bind in real www

How to attach my domain with bind in real wwwI install bind9, with apache. By God's very grace every thing went smooth. my dig, host, nslookup and ping provide this info: my system ip address: ...
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Binding domain name to Apache Virtual host on VPS

recently company I work for has rented VPS. Now i need to have multiple websites hosted on this VPS, that is not a problem, I'v set up virtual hosts, databses, etc. Now i wanted to test it, see if I ...
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How to properly configure DNS . . . from a conceptual perspective

I'm not looking for actual tools or techical how to type answers here. I'm in a complex networking environment, and I'm trying to understand the constraints on my choice of a hostname / domain / DNS ...
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List all DNS Servers, including those pushed by VPN

I want to know which DNS servers are in effect when I run commands like nslookup, dig, host, ping, etc. The general answer is to cat /etc/resolv.conf, or to look at NetworkManager, but that's only ...
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How to configure Unbound to use DNSSEC?

I'm having a local caching DNS server: Unbound: [root@localhost /etc/unbound] cat unbound.conf server: interface: 127.0.0.1 access-control: 127.0.0.1 allow verbosity: 1 ...
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Define custom DNS server when looking up host

I'm having trouble with my current web host's DNS server which doesn't correctly resolve IP addresses for Baidu. shell_exec('host -W 2 180.76.5.168'); shell_exec('nslookup 180.76.5.168'); Is there ...
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CentOS VPS - Pointing my Domain name to the VPS static IP

I am a Linux Newbie. I have a VPS with CentOS installed at my ISP and I am managing it remotely. Up to this point, I have had shared webhosting on a Linux machine at my ISP where I had CPANEL ...
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Solaris 11 nslookup reverses ip

From (Solaris 11.1 with current patches, m4000 128GB) syslog: Jun 17 10:06:14 sun-m4k-03 sendmail[4993]: [ID 702911 mail.warning] gethostbyaddr(10.128.4.50) failed: 1 The ip is valid from the ...
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Always look up non-FQDN domains as .example.com?

When I connect to the company OpenVPN they don't push their DNS to my computer, which means I have to type the FQDN for the hosts I e.g. SSH and HTTP to. Question Is it possible to configure my ...
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Ubuntu 12.04 resolver setup

When investigating how the DNS setup of my os (Ubuntu 12.04) works, I came to some questions I could not really find on the web. So what I observed was, that ubuntu uses Dnsmasq as a DNS resolver. ...
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How can I be sure that access to my home server from my home network is not done via Internet?

As advised in this question: Network file-sharing between Linux and Android, I have decided to use ownCloud to store files on my home cloud server. However, my needs have changed a bit. I want to be ...