DevOps Beta

Questions tagged [networking]

Ask Question

The tag has no usage guidance.

40 questions
Info Newest Frequent Votes Active Unanswered
0
votes
1answer
9 views

How to perform low-level inspecting of a Docker network traffic?

I'm currently in a scenario that requires Docker container C to be able to intercept communication between docker containers A and B, without their knowledge. I am basically attempting to do a ...
0
votes
1answer
30 views

Is there a way to map ports two docker container

Let's consider two docker conatiner named app and mysql. I am looking for a way, where I can map app and mysql ports, so that if I try to connect to mysql from web, using localhost:3306 it can connect....
0
votes
0answers
23 views

Container unable to connect to external Oracle DB only on specific host!

I have built an image based on the corporate JDK image for our Java application, which needs to connect to Oracle DB. I deployed it using docker stack on TWO other servers in another availability ...
5
votes
2answers
56 views

Securing communication between cloud VMs without private networks. Any strategy besides building own VPN? Spiped?

I am working on an application that requires a number of different services (web application + database + worker queues, XMPP server for messaging, redis, central authentication via LDAP, etc). For my ...
0
votes
0answers
9 views

Virtual Switching Sanity Check - BGP

I have a home Kubernetes cluster that runs in 4 VMs on top of Proxmox. Proxmox is tagged to VLAN 20, the Kubernetes VMs are tagged to VLAN 40. The Kubernetes VMs are BGP neighbors of my router so ...
0
votes
1answer
51 views

External access to internet from Kubernetes Pods

I'm having troubles with network access from pods. I had installed new Kubernetes cluster with flannel-network plugin, Checking the health of server - good. I tried to check network via busybox: ...
0
votes
1answer
26 views

Dockerized MySql slower in Wifi than ethernet

When I try to connect to a MySQL server that runs in a docker container(in System A) through my application(Running in system B) via wifi, it takes at least 4X amount of time than it would when both ...
0
votes
0answers
20 views

Access resources on local network from within K8s pod

I have a Kubernetes pod running on a bare-metal cluster. How can I access a resource on the local network from within the pod? For example: From within pod my-pod-abc123 ping 192.168.0.4 Currently, ...
1
vote
1answer
27 views

How to attach two (or more) networks to a container so they are available when the container starts?

I noticed if you try to attach a container to two networks, the following syntax does not cause an error, but effectively attach the container only on the network specified by the last --network: ...
1
vote
1answer
19 views

What are the benefits of spreading the various services of a multi-tiers application over several user-define bridges?

I have a simple system made of a database backend, several instances of a web application and a load balancer. Each service is running in its own Docker container, all of them being hosted on the same ...
0
votes
1answer
48 views

container on same network with host

Our application is a combination of 4 different applications. The graphics part is running on a host and other 3 applications are running on 3 different VMs. Which uses bridge networking. eg. ...
4
votes
2answers
1k views

How to get kubernetes pod network CIDR

I have a running k8s cluster initialized with kubeadm. On initialization, I did not pass the option --pod-network-cidr How do I get the CIDR of the pod network I tried Looking at the /etc/...
0
votes
1answer
40 views

call container B inside container A using docker networks

I have two docker containers A and B that runs on the same user-defined network. Container A has a port published, container B hasnt. I do my requests on container's A published port, but container A ...
-1
votes
1answer
212 views

Accessing container by domain name

hey guys I have a docker container A with a domain name attached to it on a host B with a domain name attached to it as well.....how can I access the said container A via A's domain name rather than ...
1
vote
1answer
45 views

Docker: subnet clients can't ping other subnet

Two containers are created with this Dockerfile: FROM ubuntu:18.04 RUN apt update && apt upgrade -y && apt install -y vim iputils-ping net-tools tcpdump iproute* iptables traceroute ...
0
votes
0answers
63 views

How to filter the ingress traffic to a docker container by changing IPtables in docker host machine

There is an apache server is started in a docker container and it acquires following IP address 172.21.0.3 The gateway IP and prefixlen is as follows 172.21.0.1/16 and the virtual interface attached ...
2
votes
1answer
77 views

phpMyAdmin using dockerised database

I have installed mariadb inside docker container, and mariadb is running properly inside that container. I want to get access of mariadb through phpMyAdmin from outside docker container. What will I ...
1
vote
0answers
656 views

How do I fix a “heartbeat failure” in Docker Swarm?

My cluster is currently located in a single data center. I've been trying to change that by adding a single worker node from another data center, but so far it hasn't worked. I'm able to make this ...
0
votes
0answers
87 views

Can ping service by its DNS x.x.svc.cluster.local but failed pinging by IP

From inside the pod: dig postgres.default.svc.cluster.local ;; QUESTION SECTION: ;postgres.default.svc.cluster.local. IN A ;; ANSWER SECTION: postgres.default.svc.cluster.local. 5 IN A 10.10....
0
votes
0answers
91 views

How to intercept and redirect network communication inside docker containers?

I am fairly new to Docker-compose and have been tinkering around a bit. in the process, i came across a requirement where i need to close down external internet traffic, and redirect requests to ...
-1
votes
1answer
48 views

2 IP addresses for one machine, which would allow to expose 2 services on the same port, but on different ip

I am using SoYouStart dedicated server (from OVH family). I bought another ip. I added auto eth0:0 iface eth0:0 inet static address xxx.xxx.20.182 netmask 255.255.255.255 ...
2
votes
1answer
167 views

Docker won't create a bridge network without being given an explicit subnet

The problem The problem is that this happens: $ docker network create alpine4 Error response from daemon: could not find an available, non-overlapping IPv4 address pool among the defaults to assign ...
0
votes
1answer
44 views

pod to pod can not be reached through service clusterIP running in the same minion

few days ago, i am facing a strange issue which is "a pod can not reach another pod running in the same minion/host through servide ClusterIP whereas they can reach each other skipping going through ...
-1
votes
1answer
56 views

Docker hostnames are not resolved in a custom network

I have the following configuration in my docker-composer.yml file. version: '3.3' services: service-1: container_name: 'service-1' build: './service-1' depends_on: - 'mongo' ...
0
votes
0answers
336 views

Enabling Docker containers to connect to Internet from laptop while running only on WiFi

These are the network interfaces I have on my Debian Linux Stretch laptop ~$ ip a 1: lo: mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:...
4
votes
1answer
4k views

Internal network between container Docker Compose with outgoing connection

I am a newbie to Docker. I am trying to run my application containing from multiple containers Here is my docker-compose.yml file version: '3.3' services: php-service: container_name: 'php-...
1
vote
0answers
132 views

Using IPTable to restrict traffic to a Docker container

I've spun up a web server that listens on port 8080 like this: # docker run --rm -p 8080:8080 python:3.6 sh -c "cd tmp && python -m http.server 8080" I want to dynamically adjust iptables ...
0
votes
0answers
24 views

Connect LAN Network to VPN with PiVPN

i am new to computer networking so i thought i could get some practice on my home network. i have 2 raspberry pi's in my lan network, and i am using the free tier EC2 instance from AWS. RPi-1 is ...
1
vote
2answers
459 views

Join a Linux Docker swarm with a local Windows Docker for test purposes

I'm currenlty trying to connect/join a Linux Docker Swarm cluster with my Windows machine in order to test a stack without sending the stack over and over to my test cluster under Linux. My problem is ...
6
votes
2answers
2k views

Why should you do port mapping for docker containers?

I have been using docker for a few months and I am just a developer not a DevOps or a networking person. However, I came across a docker-compose which maps an external port to an internal port. ...
1
vote
2answers
3k views

VPN container providing access to host's LAN?

I'm kinda new to this Docker thing and I'm interested in getting a biffed up VPS for some containers (websites/data, mysql, nginx, rocket.chat, etc) but I wouldn't like to access them in the wild (...
1
vote
0answers
515 views

Understanding Docker swarm networking and ports accessibility on the host

Given the simplest example, the test swarm consists just of one node so all containers run in one place. The stack is setup to run in a custom Docker network; the containers are not directly mapped ...
5
votes
1answer
301 views

Networking between Docker containers

I have a docker container 'A' on a host 10.11.12.13 listening on port 0.0.0.0:8443->8443/tcp I have another container 'B' on same host how wants to talk to 'A' on 8443 via host. Thus when I run ...
3
votes
3answers
187 views

SSH tunneling on steroids

I have a remote redis machine with no ssh and no open ports except to the same lan + a remote machine (on the same lan) with ssh + my pc outside the lan. What I'm trying to do (mostly to see if it's ...
1
vote
1answer
97 views

How to identify the physical IP of where Kubernetes API server runs

Question In a Kubernetes cluster, there is a Docker network IP which looks to be the API server. However, not sure how to identify the physical IP and location of the box in which it is working. If ...
0
votes
1answer
22 views

Dynamic service redirections in Docker

Imagine you have decided to abstract from exact service location. Normally, you have a cody world with the service name=DNS. Say, you have prototyped something with S3 compatible API like exoscale/...
2
votes
0answers
25 views

Weird behavior of the Docker Client on Windows 10 [closed]

There is an - as perceived - unsystematic behaviour of Docker client to setup an IPv6 connection to registry, even if this is disabled in daemon.json. Client error: dial tcp: lookup ******** on [::1]...
1
vote
1answer
686 views

Docker daemon error on joining swarm node - could not find local IP address - unknown port

Consider the following setup: Three hosts in the same network: Host A - SLES Host B - Ubuntu Host C - Ubuntu Then, the following has worked: Init swarm on A Join swarm at B, make B a manager The ...
1
vote
1answer
296 views

Debug Docker DNS

In a stack with higher number of services it seems that Docker DNS does not work anymore which leads to effects that container's names are not known even to themselves. While I have filed this bug, I ...
5
votes
1answer
255 views

How to prevent Azure Traffic Manager from routing over high latency connections in a fail-over scenario?

We have a service hosted in four regions, two in North America and two in Europe. We are using Azure Traffic Manager to provide: Performance-based routing - that is routing consumers to the service ...