Setup DNS that only offers A records for root domains to work with heroku

My client’s DNS (uniteddomains) only allows A records for root domains. But this isn’t possible with heroku. We cannot change the DNS because of reasons.

We tried to add redirect on uniteddomains but this doesn’t work either. Is there any way to get this setup to work? Is there a service that offers some type of proxy in between? Has anybody worked with heroku and unitedomains before?

Proxy Error, DNS lookup failure for -SOS-

Hello, everyone,

please I need your professional help

I have built a new page (3 months old), and because my page speed was too low, I wanted to perform this. But I made a big mistake! I came across a platform called “” and followed their instructions and changed my server entries in my DNS provider. And that was the lockdown. My website is no longer accessible, neither on the domain name nor on wp-admin. I don’t know what to do anymore. I restored the settings on my server, but it didn’t work. And the site is also no longer live on google Console! I also have a backup restore, but it has been loading for over an hour.

This site gives no support and no solution. And the website remains unavailable now.

My Hosting.provider: Strato

I always get this error:

Proxy Error

The proxy server received an invalid response from an upstream server.

The proxy server could not handle the request

Reason: DNS lookup failure for

Thank you in advance for your help.


domain name system – DNS not resolving in all locations after a week

Did a little “digging” (no pun intended), and the root “.com” servers seem to be all aware of your current name server (using dig +trace, then manually quering all the server from through Looks like your DNS record only has a two hour TTL, which is a little long for a state of transition, but certainly not days.

Have you received any user complaints about the site transition? I manually checked one of the servers that reported your site as unavailable – and the DNS resolution worked fine for your domain. (dig -t a, which was the Holtsville NY, United States location that reports a failure. Perhaps dnschecker is not working?

DNS Spoof is Not working

I was learning DNS Spoofing in the MITM attack. It actually failed. It just didn’t work as it should have for highly secured websites like Facebook, Instagram, etc.
But, while I was randomly trying to use DNS Spoofing again and again, for one time, it did work, that too for
I was wondering how it happened. I searched for reasons why DNS Spoofing do not work, and I got all the answers related to DNS cache or something.
Then I realised, when my DNS Spoofing worked, I was actually offline. So may be, before Gmail could send any information, my DNS Spoofer successfully did it.
Also, the website is actually and not
So when I go to, it redirects me to as instructed, but since I was offline, no information was given from google.
So, for my DNS Spoofing to work, may be I need to block website as

Can you please suggest any way to block website through MITM? (No router configuration)

domain name system – How to deactivate systemd-networkd.service so that connman.service can activate DNS?

I installed Automotive Grade Linux (Halibut 8.0.0) on a Qualcomm card.
It is an embedded system with no package manager, no build tools and no functional DNS, but I can display Ethernet correctly.

sa8155:~# ifconfig eth0 up
sa8155:~# udhcpc
udhcpc: started, v1.29.3
udhcpc: sending discover
udhcpc: sending select for
udhcpc: lease of obtained, lease time 604800
/etc/udhcpc.d/50default: Adding DNS
/etc/udhcpc.d/50default: Adding DNS

Note that DHCP reports that the name servers are recovered correctly.

And I can ping the name servers:

sa8155:~# ping
PING ( 56 data bytes
64 bytes from seq=0 ttl=58 time=8.973 ms
64 bytes from seq=1 ttl=58 time=19.634 ms
64 bytes from seq=2 ttl=58 time=11.391 ms

However, I cannot use DNS to resolve names.

sa8155:~# nslookup
nslookup: write to '': Connection refused
;; connection timed out; no servers could be reached

I noticed that /etc/resolv.conf is empty
other than this comment:

sa8155:~# cat /etc/resolv.conf 
# Generated by Connection Manager

I tried to manually modify /etc/resolv.conf like this:

sa8155:~# cat /etc/resolv.conf 
# Generated by Connection Manager
search local.test

But that seems to completely disable the Ethernet interface.

I have tried to manually add a single pair of hosts and IP addresses to / etc / hosts,
but i couldn't edit this file even though i am root.

sa8155:~# ls -alF /etc/ | grep host
-rw-r--r--  1 root     root         26 Nov 13  2019 host.conf
-rw-r--r--  1 root     root     111912 Nov 13  2019 hostapd.conf
-rw-r--r--  1 root     root          7 Nov 13  2019 hostname
-rw-r--r--  1 root     root        237 Nov 13  2019 hosts
-rw-r--r--  1 root     root          0 Nov 13  2019 hosts.allow
-rw-r--r--  1 root     root          0 Nov 13  2019 hosts.deny
sa8155:~# chmod 766 /etc/hosts
chmod: changing permissions of `/etc/hosts': Read-only file system

So I tried to use ConnMan to add the DNS entries.

Here is the procedure

However, connmanctl services do not return the expected list.

sa8155:~# connmanctl services
Error: The name net.connman was not provided by any .service files

I originally posted this question here and one respondent suggested that systemd-networkd could be in competition with connman.

I have verified that both services work:

sa8155:~# systemctl --type=service | grep network
  systemd-networkd.service                               loaded active running Network Service                                     
sa8155:~# systemctl --type=service | grep conn

However, I understand that the systemd-networkd configuration files are located here:


And this directory is empty for me.

It has also been suggested that /etc/nsswitch.conf could be misconfigured.
Here's what mine looks like:

sa8155:/etc/systemd/network# cat /etc/nsswitch.conf 
# /etc/nsswitch.conf
# Example configuration of GNU Name Service Switch functionality.
# If you have the `glibc-doc' and `info' packages installed, try:
# `info libc "Name Service Switch"' for information about this file.

passwd:         compat
group:          compat
shadow:         compat

hosts:          localuser files myhostname  mdns4_minimal (NOTFOUND=return) dns
networks:       files

protocols:      db files
services:       db files
ethers:         db files
rpc:            db files

netgroup:       nis

DNS Issues at Godaddy – Only for somre regions?

Hi – was hoping someone here could help me figure this out because Godaddy is not taking any responsibility for this issue – granted I’m not sure yet if the issue is actually on their side.

I’m helping a friend out who is running a charitable organization, collecting money for a local food pantry. She has been in the national news for this, so I’m wondering if maybe there was some sort of hacking attempt that may have caused this issue?

Anyway, she registered two domain names at Godaddy. They were set up using forwarding to redirect to another 3rd party website that collects the donations. This was working fine for a few weeks, but suddenly stopped working a few days ago, but it seems like only for some people. For instance the Godaddy support person who was in Arizona said it was working fine for them. It was also working fine from my cell phone, but not when using wifi.

To try to debug this, I turned off domain forwarding for one of the domains and had it go back to the GD parked page. I am still seeing the same issue now. I get to the parked domain page from my phone, but from my computer the site still times out.

I have never seen anything like this before and am not sure where to start debugging this. Does it sound like a GD issue or is it something bigger? It almost seems like it is being blocked by some ISPs or even higher level than that.

Does anyone have any tips about how to proceed?

The two domain names are: (forwarding turned off, should go to parked page) (still set to forward to the other site)



cmd – Cambiando servidor DNS mediante netsh en C

finalmente estoy en la fase final de mi proyecto.

Partimos de una comparativa en la que he extraído velocidad media de distintas IP’s contenidas en un fichero .txt, así como los servidores DNS relativos a un adaptador concreto y seleccionado mediante el siguiente comando, en el cual tomaba la variable “adaptador” del teclado mediante el número de adaptador para evitar problemas de caracteres raros con tilde y demás:

printf("nLos adaptadores de red disponibles son los siguientes:n");
while (fgets(line, sizeof line, f) != NULL) {
    printf("%s", line);

printf("Escriba el numero del adaptador del que quiere consultar servidores DNS (columna izquierda): ");
leecad(adaptador, 100);
strcpy(str, "netsh interface ipv4 show dnsservers ");
strcat(str, adaptador);

Me veo en la necesidad de modificar el servidor DNS por una IP almacenada si su tiempo de respuesta es menor. Entiendo que a través de un “if…” no es nada complicado, pero el comando netsh que debiera lanzar me dificulta un pelín las cosas:

netsh interface ipv4 set dns name=adaptador static ipganadora

Éste es el comando que tengo entendido que debo usar, tomando “adaptador” e “ipganadora” como variables. Pero tomando adaptador como un número en lugar de una cadena de caracteres, desconozco si tengo alternativa numérica para ese comando omitiendo caracteres especiales.

google – How to debug email issues with gsuite after DNS switch

We recently switched our DNS provider for our domain from Namebright to AWS Route53. Everything is working properly except for one strange issue.

We’re currently not able to receive emails from our Mandrill account (using Mandrill SMTP) to our domain email addresses managed by gsuite. To be clear, our Mandrill emails are working in general. Every email address is able to receive emails from our Mandrill account, including our personal gmail addresses. Also, our domain email addresses are able to send emails and receive emails from any other source, just not from our Mandrill account.

We’re at a loss as to how to debug this issue. We suspect the issue must be with gsuite because Mandrill says that the emails were delivered successfully. What could the issue be?

Extraer y comparar DNS en C

Tengo mi código funcional para obtener la mejor opción (el que ofrezca un entero menor como tiempo de respuesta) entre distintas IP’s listadas en un archivo “.txt”, una encima de la otra y separadas por saltos de línea. Ahora me hace falta obtener lo mismo, en un módulo distinto que accede a un fichero redireccionado igualmente “.txt” pero con distintos servidores DNS rodeados de cadenas de texto de tipo caracteres. Necesito ser capaz de extraer únicamente los enteros (siendo servidores DNS, todos siguen un formato establecido tipo XX.XX.XX.XXX, por si sirve de ayuda) para lograr hacer lo mismo que en mi código previo, que estaba optimizado para la lectura línea por línea en lugar de tener que seleccionar:

int best_response = 0;
char best_ip(sizeof(ipresp)) = "";
int best_valid = 0;
responses = fopen("ips_responden.txt", "r");
if (responses != NULL)
    while (fgets(ipresp, sizeof(ipresp), responses))
        int response1 = velocidad_media(ipresp);
        if (!best_valid || response1 < best_response) {
            best_response = response1;
            strcpy(best_ip, ipresp);
            best_valid = 1;
    printf("nn    Average time: %d ms.n", best_response);
    printf("    Best IP: %s", best_ip);

Mi fichero al que accedo para extraer esos servidores tendría una pinta parecida a:

Configuraci¢n para la interfaz "Ethernet"
    Servidores DNS configurados a trav‚s de DHCP:
    Registrar con el sufijo:           Solo el principal

En definitiva, necesito leer sus líneas hasta llegar al final del archivo, lanzando ping y comparando sus resultados sólo cuando el filtraje obtiene enteros siguiendo un formato preestablecido, ¿cómo lo logro?

domain name system – DNS DDOS Attack – would like to understand log

As part of a DOOS attack (largely inefectual) I am currently seeing log messages of the form:

<DATE> client <EXTERNAL-IP>#3074 (<NAME>): query: <SAME-NAME> IN RRSIG + (<ONE-OF-MY-IPs>)

My reading of the DNS log suggests that this is a query coming from < EXTERNAL-IP >, with the result to be sent to < ONE-OF-MY-IPs >. Is that correct?

We are running an older BIND, soon to be upgraded, but I was hoping to understand what this query is actually doing (many are sent).

Edit: Also, would be nice to know how they are able to structure it to send the result to another IP.