Questions tagged [dns]

This tag should only be used when it's about configuration of DNS on an on topic network device. Any general DNS service related questions are off topic.

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Preferred anycast paths for DNS with Quagga BGP

Background and goal Am setting up high availability DNS servers based on Unbound. Both DNS servers has in reality twelve BGP sessions against different routers but to make this easier only one router ...
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1answer
1k views

2 different servers listening to same port and same public IP [closed]

I am running 2 VMs that they both are listening to ports 80/443. I have just one public IP and several subdomains that are pointing to my public IP. I would like to somehow be able to access both VMs ...
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2answers
6k views

fortigate 50e conditional forwarding

my first post here, any help is appreciated. I have a fortigate 50E with a bunch of PCs connected to it which form my internal network. One of the PCs is running a web app (Confluence to be precise). ...
2
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1answer
175 views

Juniper SSG Split DNS not working over tunnel

I am trying to get the DNS Proxy feature working in an SSG5 (Side B). The other side of the VPN is an SSG140 (Side A). The DNS server is on Side A. foo.com should send DNS queries to 192.168.1.2 (...
1
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1answer
296 views

Why only 13 adresses for the DNS root zone [closed]

I know about anycasting and I know about the UDP limitation. Now, I was reading this article and it says the following (emphasis mine): Each IPv4 address requires 32 bytes. Accordingly, the ...
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2answers
1k views

What is route 66 in the context of DNS?

There is route53 which in the context of AWS is their DNS service. However, I've heard the term "route66" on different occasions in the context of DNS, but it never made sense to me. I tried ...
0
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1answer
141 views

Nameserver availability within single ASN [closed]

I've heard someone say today that a highly available domain name should be configured using nameservers located in different ASNs. I've however taken a look at the namesservers for google.com and all ...
0
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1answer
113 views

Can't resolve hosts after adding manually setup DNS servers on windows machine [closed]

I have setup as shown in this picture. I configured a bind9 dns server on ubuntu (192.168.242.11) When I set this as the DNS server for the Test Machine, it can resolve hosts perfectly well. When I ...
0
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1answer
2k views

External DNS intermittent issue on anyconnect remote vpn

I have a anyconnect remote vpn profile where I am having the problem with intermittent issue with external dns. I can not open any external weblink and cant ping it with name but accessing them with ...
0
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1answer
42 views

Find IP's owner instead of carrier [closed]

I have a list of IP addresses and I want to find out their owner. In many cases dig returns the name of their carrier for example AT&T. Is there a way to overcome this and find the company at ...
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2answers
81 views

StackExchange.com IP from Google DNS doesn't work, BUT IP from Whois Database works [closed]

There is a strange issue in my office building. According to Google DNS 8.8.8.8, StackExchange.com and StackOverflow.com IP address is 198.252.206.16. Outside of the building's internet connection, ...
3
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1answer
381 views

Who generates all the DNS requests when I plug my public IP router to the network?

When I plug my router with a public IP address on it into the network, I get discovered after few hours to days and become 'flooded' with DNS requests from many sources. Who generates these requests? ...
4
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2answers
3k views

Host IPv6-only website and allow access to IPv4-only clients

Lets say site.example.com runs only with AAAA records, and I wish to access that site from IPv4-only network, and I don't want to do tunneling neither other protocols that masquerades IPv4 over IPv6 ...
1
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1answer
3k views

DNS Caching Server on Cisco Router - How to set Forwarder timeout and retries?

I have configured a Cisco 1921 router to act as a DNS Caching Server by using the following configuration snippet: ip dns view default ip dns server ip domain retry 1 ip domain timeout 1 ip domain ...
0
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1answer
372 views

Per VLAN DNS Host Override Using Same Name

Is there a way to setup PFSense so that each VLAN get's a different DNS Host Override for the same domain. As in, if I have 2 VLAN's and a client on each one goes to internalsite.com, it will ...
1
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1answer
46 views

Router decision making w.r.t web browsers

Two different websites have been opened from two different browsers(for instance chrome and firefox) on the same IP Device(PC) connected to the same router. When the response comes from far end, it's ...
0
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1answer
372 views

Remote VPN connectivity - international - DNS geolocation [closed]

I am setting up Anyconnect for multiple organizations with offices world wide. They are going to be sharing two Azure data centers which have vASAs, one is in Europe and the other is in the US. At ...
0
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1answer
620 views

IPCP DNS : Configure-Reject [closed]

I'm working with a VxWorks PPP server running on an embedded system. There seems to be a problem with IPCP DNS negotiation. Each time the PPP server offers a IPCP to a client, the client seems to be ...
2
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1answer
2k views

Ping domain name using sourced interface

Problem: I want to be able to ping a domain name, sourcing from a particular interface on a Cisco router. Scenario: I have Router-A, an it has a management address of 1.1.1.1. I can only connect to ...
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3answers
2k views

Can I route internal DNS requests to another server?`

I have a bunch of internal computers, accessing a specific DNS server (internal Server). I'd like to setup some redundancy, in the event that DNS Server goes down, and quickly set routes, at the ...
1
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1answer
7k views

How to configure a DNS & web server and allowing them to serve two different subnets [closed]

I'm new to networking and I'm a little confused so could do with some help. I am currently using Cisco packet tracer and I am trying to configure a fictitious network. Initially I was just trying to ...
1
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1answer
75 views

Access load-balanced website when DNS lookup is restricted on server [closed]

The scenario is - I need to send push notification to Apple push server hosted at gateway.sandbox.push.apple.com. This Apple server is load balanced and the destination IP address can be anything in ...
0
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1answer
623 views

Can anyone please explain me DNS and DHCP in easy languguage [closed]

Hey I just started to learn Networking and I have some problems understanding the DNS and DHCP. I tried many books but they defined it a total technical language and I can't understand them. So can ...
0
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1answer
97 views

Access hosted site from behind local network?

I have a Windows server 2012 R2 machine running RRAS and DHCP. It has two ethernet interfaces: one for incoming internet traffic, and one for the local network. This server also forwards various ...
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2answers
439 views

Connecting to remote device via hostname that gets its IP from DHCP [closed]

I currently manage ~600 devices in remote sites. We use a proprietary software to monitor these devices, and currently configure static IPs for every device. This requires us to have knowledge of ...
0
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1answer
2k views

pfSense Web UI not showing Dynamic DNS IP address

I'm running pfSense 2.2.6-RELEASE and have configured two DynDNS providers: no-ip.biz and nsupdate.info. (I added the latter since no-ip.biz started nagging that I need to log in every 30 days and ...
1
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1answer
45 views

How do you check glue records if your ISP blocks access to the root servers? [closed]

Glue servers, apparently appear in the parent of the domain. How can these be queried, when for the last few months ISPs have been blocking access to the nameserver ports due to DoS attacks with ...
0
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1answer
522 views

Load Balancing System For 2 Servers on Different Datacenters [closed]

I am using Ubuntu 15 and I need to implement simple/effective Load Balancer / Fail Over System as per the below requirements: a. It should balance the load between two different public IPs (two ...
1
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0answers
75 views

University exercise - How to bridge wireless network [closed]

We are currently working on a university exercise and are stumped when it comes to replicating this network, what we are trying to achieve is wireless clients to obtain DHCP address's from a W2k12r2 ...
1
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2answers
9k views

SonicWALL TZ 300 DNS Forwarding

Clients set up with static IPs and static DNS entries pointed to my SonicWALL at 192.168.0.1 fail to resolve DNS lookup request. Client DNS -> 192.168.0.1 (DNS look ups fail) Client DNS -> Dynamic (...
11
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2answers
6k views

Cisco ASA double NAT with DNS translation

I'm trying to set up double Auto NAT with DNS translation on Cisco ASA 9.0(3), and I'm having a few challenges with the DNS portion. I got double NAT working correctly, such that I have a server in ...
1
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1answer
122 views

Understanding DNS cache poisoning

I try to understand how queries from end-users to the DNS server, can posion the cache of the DNS server. Example : I try to understand how can attackers that may take control over a computer , can ...
2
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2answers
62 views

Why does host+curl take longer than host alone and curl alone? [closed]

I tried to test the speed of my website, so I used time curl "http://google.com" The result ended with real 0m15.589s user 0m0.012s sys 0m0.000s I tried to see what took so long, so I timed ...
4
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1answer
147 views

Copying bytes from Wireshark

Should it be possible for someone to export the binary payload (say from a UDP packet) captured from Wireshark and later send this stream as a "valid" UDP packet? Longer story: I've captured a DNS ...
1
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1answer
5k views

Configure DNS Table on Sonic Wall TZ205

I just installed a TZ-205 on our company network and I can not seem to find where I would add to a DNS table. On our Linksys LRT224 there is a option to add a domain name and an associated IP. Does ...
0
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1answer
150 views

Only DNS filter guest wireless network, but not main wireless network running through same port on switch

Ive got a setup where im using 5 x Ubquity UAP AC PROs as wireless access points. The rest of the wired network is connected straight from the smart switch (Netgear GS716T), via a patch panel, to a ...
0
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1answer
181 views

Cisco 2851 Router DNS configuration questions [closed]

I'm using a Cisco 2851 Router and configuring through the Cisco Command-Line Interface and I'm trying to block certain https websites. Since I have heard that this router only has support for blocking ...
0
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2answers
55 views

Packets: How are they affected with DNS configurations? [closed]

Sorry if this is a very basic question. I'm trying to learn as much as I can about how packets are sent across the different layers on Protocol Stack. One confusion I have is with DNS protocol. When ...
1
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1answer
62 views

Applying IP of a router in another router as a DNS server [closed]

There are 2 router let it be X and Y. For X I have registered on ddns and got a hostname for the router and applied that for remote management. In Y router I have applied the fixed public IP of router ...
3
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3answers
10k views

Why can't I do a reverse DNS lookup on this IP address? [closed]

I keep noticing that web pages I have open are exchanging messages with third party servers without my permission. This is somewhat annoying, and I would like to find out which pages they are so I ...
3
votes
3answers
513 views

What exactly is a domain in context of DNS? [closed]

I am trying to understand the DNS. Say I have a domain named mydomain.com. And let's say that we have the following FQDNs: sub0.mydomain.com sub00.sub0.mydomain.com sub01.sub0.mydomain.com sub000....
1
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1answer
369 views

Explanation of different parts in DNS message format

I am studying about DNS servers, but have not clear idea about some parts of DNS message which are pointed in following figure: One of the things I am not clear about is Questions. Can there be ...
5
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1answer
2k views

Where is dns root server located? [closed]

I have some question regarding DNS root server. Where is it located ? In USA ? In europe ? Which company spends money to maintain dns root server ? What about fail-safety ? If root dns fails where ...
3
votes
3answers
3k views

DNS Resolution:<Backwards IP Address>.in-addr.arpa [closed]

Can somebody please explain whats going on here? localuser@localhost:~$ host 127.0.0.1 1.0.0.127.in-addr.arpa domain name pointer localhost. What's up with the IP address being resolved ...
3
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2answers
1k views

Choosing between BGP (AS Number) and Dynamic DNS

I have a client that provides an online API service that requires 100% uptime but has been facing connectivity challenges from ISPs. They started out with one ISP (ISP-A), who of course when there ...
0
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1answer
735 views

Is NAT loopback the only reason I can't view my own website from within my LAN? [closed]

I am new to this so apologies if this is the wrong place for such a question. I'm testing out a simple "hello world" website hosted at home. As we have not been assigned a static IP address by our ...
4
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3answers
631 views

Cannot access certain web page. Ping succeded traceroute didn't

This is my first question on forums at all. I work as a network support engineer and I have a little issue at work and I would really appreciate advice from you. Cannot access the url www.reach2.org ...
1
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1answer
691 views

internal dns for dmz server? [closed]

I have a windows server that's on the domain which has been put in a DMZ. All traffic from the internal network is allowed into the DMZ, but everything initiated from the DMZ heading in is blocked. I'...
4
votes
1answer
809 views

Why do some AAAA records behave strangely on existing A records?

I noticed the following odd behavior with AAAA records when querying existing A records. By base domains I mean domain names without subdomains. So when an A record exist and an AAAA record does not ...
0
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1answer
76 views

Host Can't be Resolved Anymore

We are using an application running on a local server, which is linked to a domain-name via a DMZ in a router. Of course, the link between the ISP IP address and the domain name is established as well....