Hot answers tagged dns
7
So does anyone know a dns longer than 40 characters?
No, but I typed world's longest domain name into Google and found this:
www.thelongestdomainnameintheworldandthensomeandthensomemoreandmore.com
Now I do.
40 characters, because apparently that's how many bytes Dnsapi reserves in memory.
Noting that 40 characters is not necessarily 40 bytes ...
6
DNS Doesn't propogate the way you probably think it does. The only "propgation" is within the servers authoritative for a domain (ie, the com. TLD).
Only registrars can update TLD NS and Glue records. It's tracked which registrar currently registers a domain name.
There's extremely little verification of record integrity, which is why cache poisoning is ...
5
Some ideas:
Are you SURE this is your localhost? Or... could it be that your DNS server is also running IIS and serving that default page for domains that do not resolve? Have you tried disabling your local IIS server?
Also blaming the DNS server, could it be that the DNS server returns 127.0.0.1 for non-existent domains?
Have you checked the local routes ...
4
I figured it out! It was the HealthAlertsSvc (Windows Server Health Service). It looks like the health service on my Windows Home Server 2011 machine crashed, and that revealed a bug in the client side HealthAlertsSvc where it wouldn't release the UDP ports correctly.
To double check that this was the case. I disabled the service on the server side and on ...
4
Port 53 is indeed the port that a DNS server listens on for requests.
However, by default it's UDP port 53, and TCP port 53 is not often used.
Your dig and nslookup commands use UDP by default, but in your dig command you specified to use TCP with +tcp, and since the router is only listening on UDP, the request fails.
To resolve the issue, query with UDP ...
3
Yes, there is a service like that: http://freedns.afraid.org/
You can login there and have free subdomains you can use for testing.
For example, right now i have "web.leet.la" pointing to "192.168.1.1".
And just for you there is "ts.leet.la" pointing to "192.168.1.128".
Feel free to do a DNS-lookup on it and use it as you need.
And if this is not what ...
2
When you configure your Cisco router to use DHCP, its IP most likely won't be 192.168.1.1 anymore.
So either set a static IP and access the Cisco admin page via this IP.
Or, if you need to use DHCP on the Cisco router, determine its current IP via the Realtek admin page (most devices acting as a DHCP server provide a list of the connected clients).
EDIT: I ...
2
Changes on /etc/hosts file only affect the local machine.
Here is the problem: Assume that your wireless hotspot (or your router) is running DHCP and also act as local DNS. When you open browser and navigate to any webpage, your browser will first look at your etc/hosts to see if there is any match entry. If not, it will ask the local DNS running on your ...
1
Your problem may be solved by adding WorkAroundBrokenAAAA to sendmail's ResolverOptions.
1) Check your current resolver options
grep ResolverOptions /etc/mail/sendmail.cf
2) Add the line below to your sendmail.mc and generate new sendmail.cf
define(`confBIND_OPTS',`WorkAroundBrokenAAAA')
3) Repeat the test
echo '3,0 cf16r@wp.pl' | ...
1
The problem could be in one of several places. The three most likely are:
Apache is only listening on localhost (instead of, say, 192.168.1.x or 0.0.0.0)
The port-forwarding isn't working/setup properly (e.g. port 8085 is forwarded to 192.168.1.12 yet your PC has changed to 192.168.1.14 since it last rebooted)
Your modem/router is not doing NAT-loopback ...
1
DNS runs on Port 53.
Port 53 is the IANA assigned port for DNS.
dig does a DNS lookup. nslookup does a DNS lookup. Thus they both use Port 53.
As to your real question, which is:
then why it is refused?
Well, that could be for any number of reasons. Maybe your Ubuntu computer is on a different network. Maybe its network cable is unplugged. Maybe you ...
1
Your DHCP server probably assigned 192.168.1.1 IP to someone else and you have duplicate IP in you network. This cause very weird behavior. If you configure static IP in your network, you should exclude them from DHCP address pool. Or you can configure your DHCP server to assign 192.168.1.1 IP to your Cisco router based on MAC of Cisco router.
1
When you do dig @8.8.8.8 wp.pl a request is sent to Google's nameserver. Google's nameserver is not authoritative for the domain wp.pl.(whatever you may have set in your search domains); (The last bit could be a source of trouble; do dig @8.8.8.8 wp.pl. in the future to stop additional searches.), and if it doesn't have a cached record to give you, it will ...
1
This question is ambiguous.
If are asking whether you can cause your machine to ping itself by changing the "/etc/hosts" file on the remote machine the answer is "No you can't".
When you execute the ping command on your machine, the first thing it does is to resolve the hostname you are pinging to an IP address. This is typically done by looking in the ...
1
Option 1:
Add a DNS entry to your existing router, this will point the domain to the correct IP address without routing all traffic through the router.
Option 2:
Run an internal DNS server which will point your domain to the correct server when you're inside your network.
Install the DNS function of your Win 2012 server and define a new forward lookup ...
1
You could add a subnetwork to your internal network like so:
You could achieve the same thing with one router/server with multiple network cards to create a DMZ or at least two different subnets.
WARNING: this should only be done when you cannot introduce subdomains into the system
1
BIND doesn't have the feature you're looking for but Unbound does. Search for "prefetch" in the documentation:
prefetch: <yes or no>
If yes, message cache elements are prefetched before they expire
to keep the cache up to date. Default is no. Turning it on
gives about 10 percent more traffic and load on the machine, but
...
1
On the IP level, What you are looking for is called Split Tunneling, and it is configured from the client (at least in non-managed scenarios). it allows requests to local lan addresses to use your local (logical) network, and requests to remote lan addresses pass through the VPN tunnel. if split tunneling is not enabled, the host connected to the VPN will ...
1
in this scenario, your router is acting as a DNS server for local requests and acts as a forwarder for unknown addresses, making the query on the 8.8.8.8 server, processing the response, and then sending back a packet indicating the result. if you use dig without a server reference, it uses the root zone to resolve, and you router will forward the lookup on ...
1
(Not really an answer but a few things you can try)
When accessing from outside your local network, do you put in your router public IP address? (And then assuming you set your router correctly, any request to the router public IP will be redirected to your NAS)
Also do check your firewall (on Router, and on NAS).
Router may have its own firewall, so ...
1
You cannot use wildcards in /etc/hosts. You will need to add every subhost separately.
Tell us more about the problem. Do you want to block traffic originating from your machine only, from the whole network? Only WWW traffic?
If you want to block all traffic to deviantart:
host deviantart.com gives 199.15.160.100
iptables -A OUTPUT -d 199.15.160.100 ...
1
Considering you're running Apache on Windows, it sounds to me like you're using NBT (NetBIOS over TCP) to resolve the hostname. Your suspicion is probably correct; this is in the same vein as Windows Workgroups, and is notoriously unreliable for a variety of reasons. Take a look here and here if you really want to dive in to it...
You're definitely better ...
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