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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736 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 ...
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3answers
636 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 ...
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1answer
692 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
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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 ...
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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....
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1answer
86 views

Who will do DNS lookup?

I am reading about computer networks. I saw some simple HTTP socket programs(In c gcc). I saw a strange thins on those programs they are using URL directly without any DNS lookup. How this thing works?...
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1answer
68 views

DNS analytics solutions? [closed]

Something like http://netfee.ustc.edu.cn/dns/ Showing top DNS queries and top clients etc. I am not seeing any open source projects doing exactly the same thing, https://www.nanog.org/meetings/...
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2answers
103 views

bind9 selective failure to resolve with particular default route [closed]

I've been running my own name servers (bind9) for many years in Linux boxes, and I have several in my office served by Verizon FiOS. This morning I discovered that I could no longer resolve anything ...
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2answers
68 views

Domain hosting IP address [closed]

Can I have a domain hosted with two different IP addresses? I recently was trying to get my domain hosting company to allocate two different IP addresses to my domain and I was told this was not ...
2
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1answer
3k views

Why does a NS record need a domain name, not an IP address? [closed]

I'm a beginning learner of DNS. Some days ago I built a authoritative name server. Writing zone files, I had wondered why the right side of a NS record is specified not in an IP address but in a ...
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2answers
200 views

How to use DDNS with scada systems that does not support domain names [closed]

We have a SCADA system that needed to pool stations via fixed IP addresses. Our station does not assign fixed IP, so we would like to use DDNS to resolve this issue. However the SCADA system does not ...
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1answer
81 views

How does Dynamic DNS know when to update IP address in the Dynamic DNS provider? [closed]

When exactly does a Dynamic DNS client update IP on the Dynamic DNS provider? Is it possible that for some short period of time (after the IP from the ISP has changed) the DNS hostname would not be ...
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1answer
1k views

DNS: retry and TTL values [closed]

I read some explanations on the Internet on the topic and also BIND and DNS 4th Edition chapters 4.2 (Setting Up Zone Data) and 8.4 (Changing TTLs). Still I have some doubts. A brief refresh first of ...
2
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1answer
450 views

Serve a different server IP to clients based on locations

I am looking for a way to server clients a different IP based on location. I'm a Casper administrator (Mac management using software by JAMF Software) and manage over 75 distribution servers globally....
2
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1answer
789 views

DF bit always set for DNS query response

When I tried packet capture with wireshark, I observed that the Don't fragment bit is always set for 1. all TCP packets and 2. DNS query response. I understood why it is so in case 1, here Now, my ...
3
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2answers
274 views

Is Reverse DNS part of the DNS protocol? [closed]

Is reverse DNS part of the DNS protocol, i.e. part of the official DNS specification? Is reverse DNS managed by standard DNS servers and a type of request that DNS servers understand and respond to, ...
4
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2answers
821 views

DNS/domain not working on cisco pix 515e

I was able to pick up a pix515e for my home network, I've got it running Version 8.0(4)28 and Device manager version 6.1(3) which I think are the latest that it will support with its 64Ram/16Flash. ...
2
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1answer
149 views

Local DNS server + Firewall for reporting Setup

My problem is the firewall is only recording DNS requests from my local DNS server instead of the source computer. I would like to keep using my local DNS server with External DNS servers being the ...
3
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1answer
11k views

Why does my router not reply to ARP requests? [closed]

I am trying to test the ability for an embedded system to create DNS requests and process their replies, but I'm having problems getting those replies. Physically, my embedded system (192.168.1.50) ...
4
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2answers
10k views

Cisco ASA VPN with split-dns on a Windows VPN client

Split DNS ostensibly allows a remote device accessing a LAN using VPN to direct DNS queries for internal domain names to internal DNS servers while queries for public domain names are directed to ...
3
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2answers
6k views

ASA as DNS transparent proxy

I'm trying to configure an ASA as transparent DNS proxy. This means that the ASA has to redirect all the DNS queries that violets a certain policy to a DNS server. For example in this way it is ...
3
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1answer
811 views

Router equipment and interface info in reverse DNS

Question about pages 17 and 18, of 49, at http://www.nanog.org/meetings/nanog45/presentations/Sunday/RAS_traceroute_N45.pdf It is mentioned that prefixes and numbers in DNS (when doing traceroute) ...
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3answers
2k views

How are the hosts in the tracert 216.81.59.173 able to use random domain names? [closed]

How are the host names in this trace route able to use random top level domains? I didn't know there was an 'Empire' or 'victory' top level domain. C:\Users\Chloe> tracert 216.81.59.173 Tracing ...
3
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1answer
1k views

Forcing Cisco DNS relay to send requests from behind PAT [closed]

I have a Cisco 1811 configured with PAT: interface FastEthernet0 ip address dhcp ip nat outside interface Vlan1 ip address 192.168.0.1 255.255.255.0 ip nat inside ip nat inside source ...
8
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1answer
3k views

DNS Doctoring / Reply Modification on Cisco 1900 series ISR

We have a Cisco 1900 ISR and have recently setup a web-server at ourdomain.com. The site works perfectly, however from the LAN we cannot use ourdomain.com to access the site, instead everyone has to ...
10
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1answer
6k views

Cisco IOS Forward / reverse name lookups

I want to configure our Ciscos so they can do forward DNS resolution, but not reverse DNS resolution from the CLI. R01(config)#ip domain-name domain.local R01(config)#ip name-server 10.1.1.1 R01(...
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2answers
1k views

Is it possible to get a listing of all DNS records that have a given CNAME? [closed]

Is there a way to get a listing of DNS records worldwide that contain a CNAME to a given domain, similar to how some sites provide a listing of domains related to a given IP address?
6
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1answer
4k views

DNS options Ironport Web security appliance

I'm running a Ironport WSA in transparent mode. In advanced proxy config - DNS Options I find the following: Find web server by: Specify how the appliance should find the location of the requested ...

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