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.
115
questions
0
votes
0answers
13 views
Archer C2 router forwards one port and blocks another [closed]
tl;dr: I have the same port forwarding configuration for two separate services on a single device attached to my TP-Link Archer C2 router. Both services are accessible internally, but only first one ...
0
votes
0answers
10 views
Windows can't use bind DNS from other PC [closed]
I am trying to host a bind dns server inside of a docker container in a docker-machine.
The docker-machine behaves like it's an own PC, so it has its own IP, which I can ping from my PC.
I have setup ...
2
votes
2answers
64 views
What are some high-traffic websites that operate with a global anycast IP address?
I've been trying to find an example of an anycast IP address used by a hugely popular service or a website.
According to my queries at https://www.whatsmydns.net/ , none of the large sites that are ...
1
vote
1answer
131 views
DNS expire-entry-timer has negative affect on ASA using FQDN ACL
I have a Cisco ASA using FQDN egress ACLs for a host that changes IP addresses every 10 mins (Apple APNS IP address pool). As soon as the TTL expires for the addresses, my internal server requests a ...
0
votes
1answer
54 views
LAN to WAN IPv4 address mapped to LAN server through NAT Rules or other
I need to set a rule that allows me to connect BOTH from OUTSIDE the LAN (from the "internet" to the Internal server at IPv4 address 10.64.0.50 via port 22, by running ssh://1.2.3.4 -p 22; AND
From ...
1
vote
1answer
52 views
How does a DNS response reach a client behind a NAT?
How does a DNS response reach a client behind a NAT? I'm talking about DNS queries using UDP for transport with a server that is not in the same network as the client.
Does the NAT correlate the ...
1
vote
1answer
32 views
Why does www DNS record propagate faster than @? [closed]
I've recently had to move a DNS ownership from one DigitalOcean account to another. During this process I've noticed that the www A DNS record propagates a lot faster than the @ A DNS record. Why ...
0
votes
1answer
34 views
Dynamic DNS and VPN [closed]
I have a few PCs/services that I want to access remotely, which are inside a VPN and gets assigned local IP addresses using DHCP.
How can I setup dynamic DNS to access the PCs on their internal VPN ...
-1
votes
3answers
34 views
ACL for DNS clarification
I do not understand why the second ACL is needed if all I want is to ensure all networks use a certain DNS server (for example 192.0.2.1)
access-list 112 permit udp any host 192.0.2.1 eq domain
...
1
vote
0answers
266 views
DNS not resolving through VPN [closed]
Looking for some help with our Office's VPN that I can't seem to solve...
I am trying to remote desktop to the Work PC from Home PC via the DC ASA 5506-x VPN. I can only connect to the Work PC with ...
1
vote
0answers
160 views
Cisco IP SLA HTTP request with frontdoor VRF
I am trying to use a IP SLA for HTTP on my Cisco ISR 4321 router to check if a website is reachable. The challenge is that I need to do that in a frontdoor VRF. I have configured
ip name-server vrf ...
0
votes
1answer
122 views
How is a lost DNS query handled [closed]
If a DNS query gets lost along the way to its destination, is nothing done about it? In my networking class, my lecturer said that DNS runs on UDP. I verified this in Wireshark by doing nslookup for a ...
2
votes
3answers
628 views
connect a cisco router to the internet through a cable modem
The router gets an External IP address via DHCP from the Cable modem
Clients inside the network get an IP address from Router's DHCP server
I can ping that the external IP address from a client inside ...
1
vote
1answer
48 views
How do I find the IP of the DNS server that respond for a specific domain name?
So as the title says I want to get the IP of the DNS server that respond when I'm trying to reach a specific domain, using bash commands.
If I understood it right, when I'm trying to reach www....
1
vote
1answer
52 views
Quanta switch not resolving addresses
I've got this brand new Quanta T3048.
I've configured the VLANs we need but it came to my attention that the switch won't resolve any address even though I've set it (according to the configuration ...
0
votes
1answer
86 views
It's not showing the DNS why it is called reverse IP lookup?
I have searched a lot but I didn't get the reason that even after giving the IP address it never shows the DNS. If it doesn't give the DNS then why it is said to be reverse IP lookup?
1
vote
1answer
209 views
Access internal webserver with domainname points to external IP
We have a webserver on our LAN.
Externally, we can use the public domainname (let's say business.com) to access the website.
Internally, we need to use the local IP.
We also want to use the public ...
1
vote
0answers
128 views
Different DNS resolution for same domain name [closed]
I am getting different DNS resolution for www.google.com.
When I am using Google Public DNS i.e 8.8.8.8 then by using nslookup then it is giving IP address of
Non-authoritative answer:
Name: www....
1
vote
1answer
357 views
Can I ping a specific site without DNS server information? [closed]
If I clear DNS cache and remove DNS server information, how can I ping to a specific site?
1
vote
2answers
2k views
How to force users on my LAN to use a specific DNS server using ARP poisoning?
I'm attempting to force all hosts on my LAN to use a specific DNS server to filter certain material, however I'm running into problems.
I've had problems in the past trying to configure my router's ...
1
vote
1answer
33 views
TZ205W DNS Issue
I have a firewall that is setup but need to have all users inside the network to use a preset dns server. While I know that I can set up this in the DHCP it does not stop a user from changing it in ...
0
votes
2answers
66 views
How can a public DNS server know the hostname of a machine on a private network [closed]
Example:
a home LAN
a simple SOHO router (both DHCP and DNS server at 192.168.1.1)
2 client machines (192.168.1.2 and 192.168.1.3)
Is it possible for the Google public DNS server located at 8.8.8.8 (...
0
votes
1answer
84 views
Iterative queries of a default DNS server
I have just started to study networks and I have a confusion about what happens when a default DNS server does iterative queries to other DNS servers to resolve a name in an IP address. I am very ...
3
votes
3answers
222 views
Can I see what happens when I run a DNS query?
My understanding is that when my computer wants to resolve a host name, it will ask the DHCP-assigned DNS servers first. If those don’t know, it goes and asks the ‘root servers’ who then defer to ...
0
votes
1answer
50 views
SRV Record for Service X [closed]
I've got a quite common question, which I can't find an answer for.
Is it possible to create a SRV Record for any possible service I'm running? For example: I want webinterface.example.com to ...
-1
votes
1answer
33 views
Is it possible to convert a public IP and port to a DNS? [closed]
Must be said, I'm a complete ignorant on these matters.
Is there a way or service so I can take and IP address and its port and make it a DNS? Is it possible or am I doomed?.
Thank you.
0
votes
1answer
56 views
WHOIS request with nodejs package failing [closed]
I'm trying to do a bulk whois lookup of around 7000 domains.
I use the node js package whois.
This worked while I tested with individual domains.
After I made a bulk request for batch of 50 domins, ...
3
votes
1answer
160 views
rate-limit dns queries on HP procurve 8212zl
I had ast week the situation that a user accidentally got our DNS server to its knees by sending over 270K DNS queries to our dnsmasq. I was looking for a reliable method to prevent this Happening in ...
1
vote
1answer
439 views
Tracert getting timeout on second packet consistenly
I'm on a vpn and tracing to virtualmachines that live in the VPN Server.
I've been experiencing slow queries, when they should be fast.
below is what the trace is returning.
I'm curious as to why the ...
1
vote
0answers
24 views
Should static IPs be set on the DNS/DHCP server, the host, or both? [closed]
Assuming a pretty regular business setup, when assigning static IPs for servers to use, should they be assigned on the DNS/DHCP server? Should they be configured individually on the hosts? Or should ...
3
votes
1answer
278 views
ASA as a local DNS resolver
I have an site to site VPN access configured by ASAs. My remote site needs to connect to the domain through the tunnel which will required DNS located on the main site. I would like to use DNS server ...
7
votes
3answers
5k views
Why is DNS an application layer protocol?
The main role of DNS is to translate Domain Names to their corresponding IP adresses, so why is necessary to be an application layer protocol?
I think that DNS is an application layer protocol ...
0
votes
1answer
846 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 ...
1
vote
2answers
5k 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
votes
1answer
158 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
vote
1answer
261 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 ...
0
votes
1answer
129 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
votes
1answer
105 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
votes
1answer
41 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 ...
3
votes
1answer
377 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? ...
0
votes
1answer
1k 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 ...
1
vote
1answer
2k 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
votes
1answer
357 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
vote
1answer
44 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 ...
4
votes
2answers
2k 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 ...
3
votes
3answers
2k views
How WANs work and why it is it bad to run DNS and DHCP on a router?
I have some networking questions about isolating networks and why it's bad to run DHCP and DNS on a router and should be run on a server.
Question 1:
What is the purpose of the WAN interface and how ...
0
votes
1answer
336 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
votes
2answers
768 views
Wireshark - capture all packets for HTTP request
I want to launch a HTTP request to a website I've never visited before. I would like to pick up all of the packets related to this request; so DNS packets, TCP packets, et cetera.
Is there a way to ...
0
votes
1answer
551 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 ...
0
votes
2answers
112 views
Is DNS geo-redundant if my traceroute to each NS shows the same location?
Some providers employ BGP anycast for their NS servers.
As a user, when doing a traceroute, many may show an identical location for both servers, for a given client.
When he.net used to anycast ...
