Domain Name System (DNS) is a service that provides the resolution of host names to IP addresses.

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How do Apache2 VirtualHosts get resolved?

As I understand it, when you request a url from a website using your browser, it asks the DNS server that the OS is pointing at if it knows the ip address that relates to the dns-name of the server; ...
5
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1answer
375 views

Firefox unable to access domains defined in /etc/hosts if Network Manager is disconnected from a network

For developing web sites, I define test domains in /etc/hosts : 127.0.0.1 example.org I can then access example.org in the browsers. However I when the Network Manager is not connected to any ...
0
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1answer
1k views

Bind DNS rate-limit and values for responses-per-second and window

In my DNS server's named.conf I see rate-limit { responses-per-second 5; window 5; }; What does this actually mean? And can it cause DNS clients problems? Is this ...
2
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1answer
236 views

Method to perform DNS lookup step very quickly during wget

When I download any document from internet using wget. It shows maximum amount of time consumed in getaddrinfo(). I know getaddrinfo() used for DNS lookup. Tell me any method, so that this time is ...
4
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3answers
28k views

How to flush local DNS cache in CentOS

(I am aware that googling this question gives me tons of stuff, but literally none worked) I'm looking for a way to flush the local DNS cache on a Centos 6 system, it is not running any DNS server or ...
1
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1answer
474 views

No DNS on Debian wifi after unplugging the DNS cable

I have installed wheezy Release Candidate 1 to my old laptop (Benq Joybook A52) right now, and I have some problem with my wireless card (Atheros 5006). It can actually see the wireless networks, I ...
4
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1answer
361 views

Setup of DNS zone with secure zone updates

How do I run a dns server with a zone for a local domain and be able to add dynamic entries to the dns zone securely from selected hosts? I have tried to setup a domain 'rag.local' with bind9. I have ...
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2answers
156 views

How to detect particular system call called or not in a whole workflow?

EDIT No. 1 My task is mirroring , i.e., copying updated data from master server to all mirrors, by using rsync and rsh. But during rsync and rsh, I found some delay. My thinking is , the reason for ...
3
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1answer
304 views

Incoming/Outgoing seperation for VPN

My situation is that I want all my outgoing connections from my Debian server to pass through a commercial VPN service I've subscribed to, but I still want to run public-accessible services on this ...
0
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1answer
230 views

Server returning 'Not Found' for “www.host.com” but not “host.com”

My server is returning the correct paths for all of my domains as long as they are not prefixed with www. The following is one of my domains in it's simplest form: <VirtualHost *:80> ...
1
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1answer
469 views

Command/scripts to check the Reverse DNS Lookup time

I am working on a project in which one master communicates with numbers of slaves. For that it has to make connection with hosts in network. But sometimes it hangs. I think that the reason behind is ...
2
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1answer
350 views

DNS cache for wget

I want wget to use a global DNS cache, not just in memory for the current instance. The wget manual mentions --no-dns-cache Turn off caching of DNS lookups. Normally, Wget remembers the IP ...
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0answers
2k views

centos 6, hostname won't resolve, dns issue, loop detected

I've searched everywhere and tried all the suggestions that I've seen, but I just can't get this to work now (it was working before). This is the first time I've ever installed a test server that I ...
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2answers
230 views

How to make dns resolve faster

I changed name server of one domain. Then I flush dns root@host [~]# /etc/init.d/named restart Stopping named: [ OK ] Starting named: ...
4
votes
1answer
3k views

“Fake” DNS for a single host

I am running a bind9 dns server at my home network, serving for all my internal servers in my domain local / 192.168.x.x - one of those, extweb.local 192.168.1.33 is also visible from the internet as ...
1
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1answer
711 views

Why is sendmail appending my hostname to unknown destination domain?

I am testing the handling of mail bouncing. When I send a test email to a bad domain, for example: eric@blahblahfail.org, I get the following error in my log: SYSERR(root): ...
4
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1answer
146 views

Alternative to DNS for internal servers

I am setting up my first network at work. All the servers are running CentOS 6.3 and have statically assigned IP addresses. For example: server1 192.168.0.101 server2 192.168.0.102 I want to be ...
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2answers
2k views

How to test DNS speed?

I am using google open DNS now. I want to test it's speed. How can I? I can ping and see that it gets faster. I need some faster way.
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2answers
428 views

Name Lookup takes a long time

I was using a script that uses curl. Quite often curl fail. The error is name lookup timed out I tried to ping google.com and and other sites. Indeed dns (or whatever do the translation from domain ...
2
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2answers
199 views

Rebuilding sendmail on FreeBSD application server after adding new activedirectory domain controller to network

In the process of adding a new ActiveDirectory domain controller to our network, we decided to rename the domain from "domain.local" to "domain.priv." I scoured all parts of our application server for ...
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1answer
431 views

Adding multiple sites at once to forward-zone of Unbound?

The usual format for Unbound forward-zone is forward-zone: name: "imap.gmail.com" forward-addr: 8.8.8.8 #googleDNS forward-addr: 8.8.4.4 #googleDNS for example. Is it possible to add multiple ...
0
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1answer
280 views

Opendns setup failed. How to fix it?

I have problems trying to configure OpenDNS. I have contacted OpenDNS support but they did not answer. I cannot access websites like Twitter and Facebook. I tried welcome.opendns.com (did not ...
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2answers
1k views

Configuring ssh fingerprints on dns to replace known_hosts fails

The SSHFP records were generated on the ssh server as follows and then added to the zone in bind: $ ssh-keygen -r www.test.us. www.test.us. IN SSHFP 1 1 ad04dfaf343a93beeb939eed1612168f7eadbed7 ...
5
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2answers
10k views

understanding DNS in ubuntu 12.04

I have Ubuntu 12.04 installed, and also use unbound and usually use openDNS as my DNS server. When I run dig google.com say I get SERVER: 127.0.0.1#53(127.0.0.1). What exactly is this thing listening ...
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2answers
787 views

In a recursive dns query what happens ttl = 0?

in name resolution (current version of bind), what happens when a recursive answer reaches ttl 0 on the return trip?
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4answers
2k views

Make nslookup use specific interface

On my computer I have two network cards. Both are using different Internet Providers service. Both Internet service provider have different DNS server and their IP address are known to me. I want to ...
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1answer
2k views

How to query RIPE database on the command line?

Using the stock whois (on Fedora) I can easily get information for an IP adress: $ whois SOME_IP % This is the RIPE Database query service. % The objects are in RPSL format. % % The RIPE Database is ...
2
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1answer
1k views

Static IP address shifting to 192.168.1.251

I have a system with a static IP address of 192.168.1.150. I configured /etc/network/interfaces manually (i.e. without using NetworkManager.) It is a web server hosting three sites. I am having ...
11
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1answer
3k views

How can I override the /etc/hosts file at user level? [duplicate]

Possible Duplicate: Can I create a user-specific hosts file to complement /etc/hosts? In short: I would like to know if it is possible to get a ~/hosts file that could override the ...
18
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4answers
16k views

What is the point of sshd “UseDNS” option?

I know what it does, but i don't know why. What attack(s) does it prevent ? Is it relevant for all kind of authentication methods ? (hostbased, password, publickey, keyboard-interactive ...)
2
votes
1answer
983 views

How do I make a registered domain name resolve to a local/private IP address

I have a Debian Linux server running on my local network. I also have port forwarding set up on my router so that computers outside my network can use my domain name and get to my website/FTP/SSH ...
2
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1answer
430 views

Strange issue with curl/lynx and non resolving domains

I have a weird issue on my server in that if I use curl or lynx to try and access a URL that doesn't exist (say a non registered domain, or a domain that's not in DNS), I don't get an error, it ...
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2answers
488 views

dig @nameserver doesn't work

I have Ubuntu 12.04 with BIND9, working just as a caching server (forwarding to 8.8.8.8). When I use, for example, dig +norecurse @l.root-servers.net www.uniroma1.it, I obtain the following output ...
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2answers
849 views

Change default DNS on openvpn connect

I am using Network Manager on Ubuntu 12.10 to connect to an openvpn server. The connection works without problems. However, when I connect, I would like to change my default DNS server to a server ...
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2answers
606 views

Best way to find out what Linux Version is used on a Webserver

Is this feasible? Can I find out which distro is used to host specific webpages? Whois doesn't have info for this.
2
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1answer
329 views

CNAME: Mail address gets rewritten

I have a problem with receiving mails. I do not know if my server or the server of the sender is wrong configured. I have a domain daniel-marschall.de which has following DNS RR: ...
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2answers
674 views

How can my server detect IP changes in order to notify my dynamic-DNS provider?

Just set up ubuntu server, which has a dynamic ip. I am looking for a way to keep my dns server updated. Im using entrydns to do this and they provide the following command to update the server. curl ...
2
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2answers
1k views

DNS Master vs Slave and Primary vs Secondary

I'm a little confused about the difference between a "secondary name server" and a "slave name server" and a "primary name server" and a "master name server"   I understand that a slave name server ...
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2answers
2k views

How to assign multiple fixed ip address for one domain?

I'm running dnsmasq, address=/chat.freenode.net/130.239.18.172 address=/chat.freenode.net/140.211.167.105 But seems dnsmasq only recognize the last record, what should I do?
1
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1answer
349 views

How can I resolve local IPs to hostnames? [duplicate]

Possible Duplicate: How to make a machine accessible from the LAN using its hostname I have is a simple home network with a few machines connecting through DHCP. If everyone and their ...
1
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2answers
96 views

Is there some kind kind of hosts.additional file for Linux

If you have a list of servers all linking to each other by static addresses, is there some kind of hosts.additional you can use as some kind of file based DNS? ie The hosts file contains static ...
6
votes
1answer
314 views

Why the difference between network addresses reported by hostname and ping?

I have tried hostname and ping in a cluster machine, with different outputs. I am wondering what is the difference between the two? For example, on the same machine, hostname outputs node4.XXX and ...
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1answer
350 views

Changing host file in Ubuntu

I tried to change /etc/hosts to change a local DNS entry, so I can map any website name to any IP, but it isn't working. How can I debug it?
5
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2answers
2k views

What is resolv.conf and why VPN client's hack it?

As stated in a previous question I want to connect to 2 VPN servers at the same time and for each connection specify the IPs of computers I want to reach with it. One of this VPN connection is done ...
1
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1answer
579 views

Howto use Google DNS with ppp

I have a mobile broadband device that I use to connect to the internet. I wish to use the google dns service, their nameservers being 8.8.8.8 and 8.8.8.4. I add them to /etc/resolv.conf but when I ...
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1answer
281 views

possible spots to configure BIND-DNS forwarders

i'm investigating our BIND's configuration and can not figure out how it is aware of it's next name server to ask for some domain he's not authorative server for... e.g. home domain is ...
2
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2answers
599 views

BIND server doesn't recognize my zone properly

I'm pretty new to BIND so I was hoping maybe someone can help me understand why I can't resolve. What is wrong? named.conf options { listen-on port 53 { localhost; 10.30.0.10; }; ...
3
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1answer
370 views

Simplest way to set up multiple subdomains to separate VMs running on single host

Problem: I´m planning to set up several virtualized centos, rhel or ubuntu guest machines on a single centos host server (most likely using KVM). Each guest VM is running an instance of a webapp + ...
3
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1answer
167 views

How to skip DNS checkup while I'm disconnected from Internet

I use RedHat machine. /etc/resolve.conf was set to nameserver 8.8.8.8 and it works well. I'm wondering how to connect my machine if it's disconnected from internet? It seems that if DNS of 8.8.8.8 is ...
4
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1answer
861 views

Creating a new TLD for private network

I want to setup a new TLD (foo.) for my the private network so that I can host some child domains which will be accessible from within the network. For this purpose I have setup a DNS server ...