Dears,
if we say that when creating a custom network we have an embedded dns 127.0.0.11. As I know that 127.0.0.11 is a loopback interface but this ip is configured where ? is it the ip of dns server ? and if so how they are able to communicate since it is like a local network on the same machine ?
thank you
Hi @rsimos
127.0.0.11 is a special local IP address used for DNS inside a network on the same machine.
It’s part of the loopback range (127.0.0.0/8), meaning it’s only reachable from the same device.
It’s not a real external DNS server, but a local service that handles DNS for programs on the system.
Even though it’s local, it works because the system or application sets up a DNS service that listens on that address.
Hello,
can you please explain more regarding process and network namespace related to this service ? where it is sitting how is it reachable from localmachine (container to the host daemon). since the container has his own namespace it should not be able to see the host processes and network. please explain the flow.
thanks in advance!
Hi @rsimos
I found a blog that explains it clearly. You can read it here: Introduction to Container Networking in Docker | taikun.cloud
I hope this image helps you understand the concept better.
Hello,
thanks for the website but it is not something that I am looking for.
I have a custom network bridge created (mycustnetwork = 10.144.144.0/24). When i connect a container to this network, I got in /etc/resolv.conf the 127.0.0.11.
when running ps -ef inside the container I only see in my example nginx and the bash processes, so no dockerd dns process. but when i run netstat -ant => i have this output:
root@5608767157f8:/# netstat -ant
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 127.0.0.11:35245 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN
tcp6 0 0 :::80 :::* LISTEN
so i have 127.0.0.11 where i can find this process ? where is it sitting ? and also i have routing rules created, so how it is resolving the dns between my container and this ip ?
and why i only have it when create a new custom network and not on the default bridge ?
thank you in advance !
