Why ping to a docker container returns "Request timed out"?

Question

I have a setup that worked for me a long time in my local computer (docker for windows 10). Recently I started using kubernetes, and now I have connection issues to my docker containers. I can docker exec bash into them, but ping to the cotainer ip doesn't work.

I am not 100% sure on how the routing works.

This is the routing that I currently have:

# route PRINT
===========================================================================
Interface List
  5...8c 89 a5 59 d0 9b ......Realtek PCIe GbE Family Controller
 14...00 ff 9a f5 da ac ......TAP-Windows Adapter V9
  1...........................Software Loopback Interface 1
 20...00 15 5d 1a 4c 88 ......Hyper-V Virtual Ethernet Adapter
 35...00 15 5d d6 58 e9 ......Hyper-V Virtual Ethernet Adapter #2
===========================================================================

IPv4 Route Table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0       10.0.0.138        10.0.0.15     35
         10.0.0.0    255.255.255.0         On-link         10.0.0.15    291
        10.0.0.15  255.255.255.255         On-link         10.0.0.15    291
       10.0.0.255  255.255.255.255         On-link         10.0.0.15    291
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    331
        127.0.0.1  255.255.255.255         On-link         127.0.0.1    331
  127.255.255.255  255.255.255.255         On-link         127.0.0.1    331
       172.16.0.0      255.240.0.0     192.168.65.0        10.0.0.15     36
   192.168.172.32  255.255.255.240         On-link    192.168.172.33   5256
   192.168.172.33  255.255.255.255         On-link    192.168.172.33   5256
   192.168.172.47  255.255.255.255         On-link    192.168.172.33   5256
  192.168.175.240  255.255.255.240         On-link   192.168.175.241   5256
  192.168.175.241  255.255.255.255         On-link   192.168.175.241   5256
  192.168.175.255  255.255.255.255         On-link   192.168.175.241   5256
        224.0.0.0        240.0.0.0         On-link         127.0.0.1    331
        224.0.0.0        240.0.0.0         On-link         10.0.0.15    291
        224.0.0.0        240.0.0.0         On-link    192.168.172.33   5256
        224.0.0.0        240.0.0.0         On-link   192.168.175.241   5256
  255.255.255.255  255.255.255.255         On-link         127.0.0.1    331
  255.255.255.255  255.255.255.255         On-link         10.0.0.15    291
  255.255.255.255  255.255.255.255         On-link    192.168.172.33   5256
  255.255.255.255  255.255.255.255         On-link   192.168.175.241   5256
===========================================================================
Persistent Routes:
  Network Address          Netmask  Gateway Address  Metric
       172.16.0.0      255.240.0.0     192.168.65.0       1
===========================================================================

The docker network:

# docker network inspect myappjose_default                                                                             
[                                                                                                                        
    {                                                                                                                    
        "Name": "myappjose_default",                                                                                   
        "Id": "28ea26ea55b012d25397029e02bb2ddd442f725b310a5bbd1ff321e563d257c2",                                        
        "Created": "2020-10-16T07:21:52.6360039Z",                                                                       
        "Scope": "local",                                                                                                
        "Driver": "bridge",                                                                                              
        "EnableIPv6": false,                                                                                             
        "IPAM": {                                                                                                        
            "Driver": "default",                                                                                         
            "Options": null,                                                                                             
            "Config": [                                                                                                  
                {                                                                                                        
                    "Subnet": "172.18.0.0/24"                                                                            
                }                                                                                                        
            ]                                                                                                            
        },                                                                                                               
        "Internal": false,                                                                                               
        "Attachable": true,                                                                                              
        "Ingress": false,                                                                                                
        "ConfigFrom": {                                                                                                  
            "Network": ""                                                                                                
        },                                                                                                               
        "ConfigOnly": false,                                                                                             
        "Containers": {                                                                                                  
            "0c78b6eb1b88447e5690caeb90343dbe345e9e32cc407a60e18aa6cacec37f53": {                                        
                "Name": "myappj1-model-container",                                                                     
                "EndpointID": "a85c982c4cb982be6ee654aa3680c50229b3a89032ba9d7b1191e530c29564cf",                        
                "MacAddress": "02:42:ac:12:00:02",                                                                       
                "IPv4Address": "172.18.0.2/24",                                                                          
                "IPv6Address": ""                                                                                        
            },                                                                                                           
            "e1b518b64b4cdc2e18412c4d53eb3342d313a476c925e4e94529a81d3fa30993": {                                        
                "Name": "myappj1-view-container",                                                                      
                "EndpointID": "c4e373e05daf55f726823bccce0aec8faf5deaef6b0223e15e692352f46653f7",                        
                "MacAddress": "02:42:ac:12:00:04",                                                                       
                "IPv4Address": "172.18.0.4/24",                                                                          
                "IPv6Address": ""                                                                                        
            },                                                                                                           
            "eaa89d990ebcb8f3f26a1e5aff5db6f0ecddbf2e07c13bc52dbb57332818ad47": {                                        
                "Name": "myappj1-controller-container",                                                                
                "EndpointID": "a0a35480e775bbab0e4a23819021751d4368b6d255ef519c89bc5ffd898441fb",                        
                "MacAddress": "02:42:ac:12:00:03",                                                                       
                "IPv4Address": "172.18.0.3/24",                                                                          
                "IPv6Address": ""                                                                                        
            }                                                                                                            
        },                                                                                                               
        "Options": {},                                                                                                   
        "Labels": {                                                                                                      
            "com.docker.compose.network": "default",                                                                     
            "com.docker.compose.project": "myappjose",                                                                 
            "com.docker.compose.version": "1.27.4"                                                                       
        }                                                                                                                
    }                                                                                                                    
]

Docker network in the settings:

And ping is not working:

$ ping 172.18.0.4

Pinging 172.18.0.4 with 32 bytes of data:
Request timed out.

and I can get into the container using docker exec (so it is working and reachable):

$ winpty docker exec -it myappj1-model-container bash
root@myappj1-model:/#

UPDATE

It seems that it is related to WSL2 that I installed this week. docker is using the wsl engine, but the wsl machine has no internet connection. Still I don't know how to get it to work

Any idea how to fix it? If you need more info let me know and I will update

Why is it important to send an ICMP packet to the container? The Docker-private IP addresses also aren't generally useful and are unreachable in many common contexts. Ignore all these very-low-level debugging tools: can you make an HTTP (or other TCP) connection to the published ports of your container? Can you provide a [mcve] including all relevant source code to demonstrate the problem? — David Maze, Oct 16 '20 at 11:09
The problem is that I used to have things that mysql workbench that connected to the control, and vscode that run tests through port 22. Both of them now not working because the containers are unreachable. — justadev, Oct 16 '20 at 13:55
If it is of any help, It seems that it is related to WSL2 that I installed this week — justadev, Oct 16 '20 at 15:31

score 0 · Answer 1 · answered Feb 26 '22 at 09:58

For benefiting the latecomers;

You need to map the container port to the host port and try to test the connection. If it's mapped, you will find a key named 'ExposedPorts' under which the ports are mentioned, when you inspect the container as shown above. As of now, you are trying to ping an unreachable IP 172.18.0.4 which is only known to the docker network.

Either you can run the container with port mappings and try to test connection. Or you can specify the port mappings inside a docker-compose.yml file and do

docker-compose up

and test the connection.

In windows to test the connection in Powershell, you can use the Test-NetConnection tool. There are many other tools also for the same see!

PS C:\Users\DMF Media> Test-NetConnection 127.0.0.1 -p 3306

Why ping to a docker container returns "Request timed out"?

UPDATE

1 Answers1