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-1

Check this solution http://mariopang.blogspot.com.au/2014/12/unable-to-save-create-reverse-dns.html I created in my blog and solve this issue


4

I recently updated a domain mapping for my domain but the TTL was several days That'll teach you to have a long TTL for no good reason! =) 3600 seconds is the most that's reasonable in the vast majority of situations. I personally prefer 5 minutes even for domains that get hundreds of requests per second or more. Actually, especially if the record is ...


7

Two people (me - the webmaster - and a regular user, for now) that accessed our site www.lastroarte.com are having ERR_NAME_NOT_RESOLVED error on Chrome and any other browsers are just not finding the page and they do not display error logs upfront, so I'm assuming its the same error. (I haven't searched for it as well) Don't rely on browser DNS cache ...


0

Yes, the nodes must be resolvable from the puppetmaster. This is one of the prerequisites before deploying Puppet (in a master/node setup), see https://docs.puppetlabs.com/guides/install_puppet/pre_install.html#check-your-network-configuration: Name resolution: Every node must have a unique hostname. Forward and reverse DNS must both be configured ...


1

To define a source IP for a rule, you use -s. In this example, you want to add -s 1.2.3.4 to your line. iptables -A OUTPUT -p udp -d 8.8.8.8 -s 1.2.3.4 --dport 53 -j ACCEPT iptables -A OUTPUT -p udp -d 8.8.8.8 --dport 53 -j DROP


1

This is indeed a common use case when one has more than one network cnnection, e.g. an internet connection (for the generic traffic) and a vpn connection (just for traffic to a company or remote site). This is a valid example for the question of the OP. I know no operating system (excluding OSX as I've learned above) which can handle this problem from ...


0

Fixed it. There were 2 core problems working in tandem which caused this.... Core problem 1: When looking at Ubuntu's /etc/hosts file, though I had no memory of ever editing it, the problem became apparent. The third line was routing to a non-existent server and I really wish I knew why. This third line was removed: 127.0.0.1 localhost 127.0.1.1 ...


5

I have added an MX record for mail.domain.com simply because it is the format I generally see in tutorials. So your email addresses are in the format user@mail.domain.com? If your email addresses are intended to be user@domain.com, then you need an MX record for domain.com My question is, does mail.domain.com need to also exist as an A or CNAME ...


5

Yes, you need an A record that corresponds to the MX record. The MX record designates which host email should be delivered to for the domain and for that you need a host (A) record. Without over complicating things, if mail.domain.com is where email for domain.com should be delivered to then the end result should be that a DNS query for the MX record ...


0

I don't have access to a Barracuda web filter, but the email appliance has a hidden "Expert Options" menu that you can access that may contain some additional settings. Login to the device, click the "Advanced" tab, and then add "&expert=1" to the end of the URL to access the hidden menu; my URL looked like this after the change: ...


5

The warning that you're seeing there isn't actually about GitHub or GitHub pages at all, but about CloudFlare's name servers. Personally, I'd argue that accurate PTR on a name server's IPv6 address really isn't a problem, per se - email is going to care about reverse resolution for the mail server, not the DNS server. We know the DNS server is valid for ...


4

You need a PTR record that resolves 128.199.39.109 to the hostname of your sending server. Might also want to look into SPF records for your domain too.


6

There is a trick you can use here. That said, Wesley is a smart dude and you should listen to him. I don't get paid to say that but I'm hoping to change that one day. Assuming that you're trying to change a record called www in a zone called example.com.... Create a temporary wildcard A record (*) in the zone. Commit the change. Test it, make sure the ...


6

We're moving across to Amazon EC2 and are using a load balancer, with the recommendation that we use a CNAME instead of an A record I sincerely hope that you're not CNAMEing your apex domain. If your DNS host is self respecting, it won't be allowed. If it's a shameful and slimy host, you'll be able to, but you'll lose a piece of your soul (but you're ...


2

Add a ServerName attribute in your VirtualHost config with the hostname you want to use.


0

I found out the problem. I'd activated cloudflare.com account for upservers.net and now by disabling cloudflare.com, and reverting back main website's DNS records, the information on intodns.com are correct again. Sorry for taking your time.


3

Yes, it's possible for you to do it, if your infrastructure can use DNS Response Policy Zones. http://en.wikipedia.org/wiki/Response_policy_zone Note that this will only work for machines you control. If you care about the wider world getting to the correct record, they won't be using your RPZ settings. In all cases, you should work with your DNS ...


2

The netmask set on the IP address which the server is using (64.x.x.x) was to 255.0.0.0, this is to wide, meaning that requests for any domains which also start with the IP address 64. were not being routed out of the server correctly. The resolution to this issue was to lower the netmask used on the IP address on the local machine to be 255.255.255.0, ...


1

Commenting out the ip6 from /etc/resolv.conf solved the issue. # nameserver config nameserver 213.133.100.100 nameserver 213.133.98.98 nameserver 213.133.99.99 #nameserver 2a01:4f8:0:a111::add:9898 #nameserver 2a01:4f8:0:a102::add:9999 #nameserver 2a01:4f8:0:a0a1::add:1010


0

The WhoISrequest Domain History Checker seems much more comprehensive than the DNS History site. I looked up information on a couple of domain names that I've had registered for over a decade using both tools. DNS History showed information for the first one I checked indicating that its information, which is out of date, was last updated on 2010-08-11. For ...


0

For the benefit of anyone else having this problem and ending up here from Google, for me the problem was caused by my use of BIND views. I had configured multiple views, assuming BIND would combine all matching views into one, but actually it picks the first matching view and uses only that one, ignoring all others. Consequently the client was only seeing ...


5

Yes, you understand it correctly. Sending E-Mail servers use MX records in order of preference defined within the MX records. The record with smallest precedence is used first, then the second smallest etc. If two servers have equal precedence, the sending server picks a random server from the equal precedence server. You can make forwarding accounts on ...


5

There is multiple things here. First you should check if your DNS provider has put it on their DNS servers yet. Some providers can take a bit of time to do that. E.g.: $ dig -t A newrecord.example.com @ns.yourprovider.com If that responds correctly, that's good already. When a client requests the new record for the first time, it will now get the ...


2

You could set your local hosts file to point at the domain to test that everything is configured correctly. Are you sure your IP address is public facing? If you are using Windows, your hosts file can be found in: C:\Windows\System32\drivers\etc You will need to add the following line: {{IP address}} {{domain}}


0

It depends on your SOA record and a record TTL. There are some time values for caching your DNS data. You can flush your DNS cache; it may help, but not always. At my DNS servers I use 15 minutes for caching.


4

It all depends on your DNS server's time to live (TTL). This metric defines how long the ISPs cache the DNS entry for. If it's set for 24 hours for example, no ISP will try that DNS server for 24 hours, because it has a cache of it already. Most TTLs are less than 24 hours however; see if you can find that metric in your configuration. It could also be a ...


0

Depending on if you mean that people can't reply to the emails, you might want to look into rewriting messages. Specifically, you can add a reply-to address to all outgoing e-mails. Depending on the specific use of your email server, this can be either configured to blanket rewrite all outgoing emails to have the reply-to value set to your company ...


0

It sounds like your Microsoft DNS server is operating in both an authoritative and a recursive role. In an authoritative role a nameserver would only provide a referral to ds.example.com., but if the client is allowed to recurse the server will chase the NS record referral and provide the requested answer. If this is an internet facing MS DNS nameserver, I ...


0

The short answer: about 25 A records fit in a UDP packet. Beyond that, DNS will switch to TCP and it will not be as fast. You'll also have problems with clients that aren't using DNS resolvers capable of picking the "nearest" IP. Also, with wifi and mobile, the "nearest" is often not going to be the right server. Longer answer: Don't do that. A better ...


1

If a forwarder is configured, dnsmasq will forward all DNS queries that it has no explicit data for. This includes records for configured static DHCP clients that have no active lease, AAAA records unless IPv6 addresses are defined explicitly, and more. There are several ways to avoid this: Don't configure a forwarder Simply omit the fowarder entries in ...


1

The @edvinas.me answer is correct. You must create a cloudfront distribution for your bucket. When you create the cloudfront distribution set the alternate Domain Names option to *.example.com. Then use the cloudfront url like d3lt3rsz2leycm.cloudfront.net. Now you can to add a wildcard subdomain like this: *.example.com. CNAME ...


0

If you disable ddns update-optimization, it should remove the records when the lease ages out. [1] 1: https://kb.isc.org/article/AA-01091/0/ISC-DHCP-support-for-Standard-DDNS.html


1

First, use nslookup to query your name servers (listed in the Route53 management console when you select your zone) directly. You do it like this: nslookup my.query.com ns-????.awsdns-??.??? If this query doesn't give you the right results, the issue is between the AWS console and Amazon's servers, so you should contact them. If this looks OK (like I ...


0

Interesting point of historical trivia on this subject. In the 90s, AOL expanded their DNS records such that an MX query would return >512 bytes. This violated RFC, broke a lot of SMTP servers (qmail being a popular one at the time), and caused sysadmins a lot of headaches. The fix required either patching, or adding static routes. I don't know what the ...


0

you have to do it other way. www.example.com IN CNAME example.com This will create a subdomain com/example with an CNAME www that point to example.com Can you try this?


2

You have to create a separate A record in your mydomain.com's DNS zone file to point your subdomain to your VPS's IP. subdomain A 5.6.7.8 If you want, you can add the complete hostname subdomain.domain.com as long as it is followed by a . (dot). subdomain.domain.com. A 5.6.7.8


3

It appears you're using GoDaddy to redirect https://sendsonar.com/ to the Heroku-hosted www subdomain. GoDaddy's DNS manager's redirects don't support HTTPS (as GoDaddy's redirect services servers don't have your SSL certificate installed).


1

This won't work, because zone transfers are handled on a zone-to-zone basis. You can't transfer a full zone to a partial zone. That said, it's possible to define a more specific zone on your master server called ec2.example.net.. Doing this will hide ec2 and all records beneath it in your example.net. zone, so you will need to ensure that all of those ...


1

Following some cursory checks (see: What Is My DNS, Pingdom, MX Toolbox), I can see that the domain is resolving correctly on various servers around the world. However: The MX Toolbox checks have shown that your TTL (Time To Live) is set to 604800 seconds. This means that any DNS recursor can cache your details for up to 7 days, so if you change your IP ...


0

As others have pointed out, it's a terrible idea for real-world use. In the real world there are nonconforming clients and resolvers that have trouble with responses that can't fit within a single UDP datagram, and there are firewalls which will enforce specific but not-protocol-compliant ideas about DNS message size limits. And even if you could count on ...


2

Others have mentioned it as a detail, but from a practical standpoint, the hard limit is the UDP packet size limit of 512 bytes. While it's possible to switch to TCP when truncation is detected, in practice many/most clients will not do it (and arguably they shouldn't; it would give bad user experience for most applications, and I would only expect ...


0

Unix.SE has two good answers for this: If you only want to disable IPv4 for APT, and you run Debian wheezy or *buntu saucy, or newer, that is, APT 0.9.7.9~exp1 or newer, you can use the Acquire::ForceIPv4 option, either on the command line (-o Acquire::ForceIPv4=true) or in apt.conf (Acquire::ForceIPv4 "true";). If you want to prefer IPv4 over IPv6 ...


2

A CNAME record defines that one name is an alias of another name (the canonical name). The implication of having an entire name be an alias is that it cannot also have records of its own, meaning you cannot have those MX records. This is also why you cannot have a CNAME record at the zone apex (where you will always need at least SOA and NS records). You ...


0

dig +trace is generally the most straightforward way to inspect the chain of delegations. However, glue records are in the additional section and by default trace output does not include the additional section. You will need to specify explicitly that you want this included in the output. dig +trace +additional example.com If the idea is to check the ...


5

What you are describing isn't an especially new idea. As other answers have already covered, you are limited in how many A records you can have in one reply, but that says nothing about how many A records there might be in total. You could, for example, implement a DNS server which answers any query for an A record with a random IP. Queried enough times, ...


2

Here is a little shell script which implements Alnitak's answer: #!/bin/sh S=${IFS} IFS=. for P in $1; do TLD=${P} done IFS=${S} echo "TLD: ${TLD}" DNSLIST=$(dig +short ${TLD}. NS) for DNS in ${DNSLIST}; do echo "Checking ${DNS}" dig +norec +nocomments +noquestion +nostats +nocmd @${DNS} $1 NS done Pass the name of the domain as parameter: ...


1

jeffsnider's answer is correct. However, be aware you can also do the 'hidden master' trick. Here your primaries slave (i.e. AXFR) from a 'hidden master'. That hidden master need only support AXFR. An easy way to achieve this is to run the nameserver of your choice and generate text files for it in perl or whatever. You need not worry about performance or ...


0

I have this working with thousands of hostnames (subdomains). You probably want a wildcard DNS record (*.mydomain.com). You can use a CNAME record that aliases this to the A record for the main domain (even if the main domain matches the wildcard, like www.mydomain.com). The wildcard record will be used for ANY subdomains not explicitly found in other ...


16

To answer the question as it was stated ("how many IPs can a single DNS A record hold?") the answer is very simple: a single A record holds exactly one address. There can however be multiple A records for the same name.


61

Disclaimer: No offense, but this is a really bad idea. I do not recommend that anyone do this in real life. But if you give a bored IT guy a lab, funny things will happen! For this experiment, I used a Microsoft DNS server running on Server 2012 R2. Because of the complications of hosting a DNS zone in Active Directory, I created a new primary zone named ...



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