docker ps shows wrong port when disconnecting and reconnecting a container. #7796
Description
Description
I am observing strange behavior in the following situation:
- create a network
- run 2 containers n1 and n2 in that network
- disconnect n2
- disconnect n1
- reconnect n2
- when checking connectivity, connectivity to n2 is not restored but to n1 it is restored.
Reproduce
- Create a network with default options
$ docker network create test
6ee2fc93a499e22342ede7b2c693ee4e9af123fc24f4e13c8e19e2ba6dcb8ebf
- Start 2 containers connected to that network
$ docker run --rm -d -p 80 --name n1 --network test nginx
2ec11c9aeb10b23dab10d89df3b829d975204f126084b69eed88f6372baf9148
$ docker run --rm -d -p 80 --name n2 --network test nginx
f4099db850f6e35fa1b411812db92d2536ec56f8ba0975eeb1bf4c4d61bb7b09
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
f4099db850f6 nginx "/docker-entrypoint.…" 23 seconds ago Up 23 seconds 0.0.0.0:52193->80/tcp, [::]:52193->80/tcp n2
2ec11c9aeb10 nginx "/docker-entrypoint.…" 28 seconds ago Up 28 seconds 0.0.0.0:52191->80/tcp, [::]:52191->80/tcp n1
- Check connectivity
$ curl localhost:52193
<!DOCTYPE html>
<html> (...)
$ curl localhost:52191
<!DOCTYPE html>
<html>
-
Disconnect the 2nd container from the network
$ docker network disconnect test n2 -
Verify connectivity
$ curl localhost:52193
^C // dead as expected
$ curl localhost:52191
<!DOCTYPE html>
<html>
(...) // alive as expected
- Disconnect n1 and verify connectivity
$ docker network disconnect test n1
$ curl localhost:52193
curl: (56) Recv failure: Connection reset by peer // as expected
$ curl localhost:52191
curl: (56) Recv failure: Connection reset by peer // as expected
- (Re)connect n2
$ docker network connect test n2
$ docker network inspect test
[
{
"Name": "test",
"Id": "6ee2fc93a499e22342ede7b2c693ee4e9af123fc24f4e13c8e19e2ba6dcb8ebf",
"Created": "2025-10-27T13:47:32.852200342Z",
"Scope": "local",
"Driver": "bridge",
"EnableIPv4": true,
"EnableIPv6": false,
"IPAM": {
"Driver": "default",
"Options": {},
"Config": [
{
"Subnet": "172.16.1.0/24",
"Gateway": "172.16.1.1"
}
]
},
"Internal": false,
"Attachable": false,
"Ingress": false,
"ConfigFrom": {
"Network": ""
},
"ConfigOnly": false,
"Containers": {
"f4099db850f6e35fa1b411812db92d2536ec56f8ba0975eeb1bf4c4d61bb7b09": {
"Name": "n2",
"EndpointID": "a2c2b1e4d0dea3c5dd04d5d343c498508f59e0b2ec7954b1ea5bdc073ba02a8a",
"MacAddress": "86:ff:4c:de:63:4d",
"IPv4Address": "172.16.1.2/24",
"IPv6Address": ""
}
},
"Options": {
"com.docker.network.enable_ipv4": "true",
"com.docker.network.enable_ipv6": "false"
},
"Labels": {}
}
]
It says that network n2 is connected.
- Check connectivity via curl
$ curl localhost:52193
curl: (56) Recv failure: Connection reset by peer
// Wait, what?? Port 52193 is associated with n2 that was reconnected.
$ curl localhost:52191
<!DOCTYPE html>
<html> (...)
// Now, wait again.... n1 is now connected although we did not change its state?
Expected behavior
I was expecting a result for this command:
$ curl localhost:52193
and a connection error for this command:
$ curl localhost:52191
curl: (56) Recv failure: Connection reset by peer
docker version
% docker version
Client:
Version: 28.5.1
API version: 1.51
Go version: go1.24.8
Git commit: e180ab8
Built: Wed Oct 8 12:16:17 2025
OS/Arch: darwin/arm64
Context: desktop-linux
Server: Docker Desktop 4.49.0 (208700)
Engine:
Version: 28.5.1
API version: 1.51 (minimum version 1.24)
Go version: go1.24.8
Git commit: f8215cc
Built: Wed Oct 8 12:18:25 2025
OS/Arch: linux/arm64
Experimental: false
containerd:
Version: 1.7.27
GitCommit: 05044ec0a9a75232cad458027ca83437aae3f4da
runc:
Version: 1.2.5
GitCommit: v1.2.5-0-g59923ef
docker-init:
Version: 0.19.0
GitCommit: de40ad0docker info
% docker info
Client:
Version: 28.5.1
Context: desktop-linux
Debug Mode: false
Plugins:
ai: Docker AI Agent - Ask Gordon (Docker Inc.)
Version: v1.9.11
Path: /Users/rr26ua/.docker/cli-plugins/docker-ai
buildx: Docker Buildx (Docker Inc.)
Version: v0.29.1-desktop.1
Path: /Users/rr26ua/.docker/cli-plugins/docker-buildx
compose: Docker Compose (Docker Inc.)
Version: v2.40.2-desktop.1
Path: /Users/rr26ua/.docker/cli-plugins/docker-compose
debug: Get a shell into any image or container (Docker Inc.)
Version: 0.0.45
Path: /Users/rr26ua/.docker/cli-plugins/docker-debug
desktop: Docker Desktop commands (Docker Inc.)
Version: v0.2.0
Path: /Users/rr26ua/.docker/cli-plugins/docker-desktop
extension: Manages Docker extensions (Docker Inc.)
Version: v0.2.31
Path: /Users/rr26ua/.docker/cli-plugins/docker-extension
init: Creates Docker-related starter files for your project (Docker Inc.)
Version: v1.4.0
Path: /Users/rr26ua/.docker/cli-plugins/docker-init
mcp: Docker MCP Plugin (Docker Inc.)
Version: v0.24.0
Path: /Users/rr26ua/.docker/cli-plugins/docker-mcp
model: Docker Model Runner (Docker Inc.)
Version: v0.1.45
Path: /Users/rr26ua/.docker/cli-plugins/docker-model
offload: Docker Offload (Docker Inc.)
Version: v0.5.1
Path: /Users/rr26ua/.docker/cli-plugins/docker-offload
sandbox: Docker Sandbox (Docker Inc.)
Version: v0.3.1
Path: /Users/rr26ua/.docker/cli-plugins/docker-sandbox
sbom: View the packaged-based Software Bill Of Materials (SBOM) for an image (Anchore Inc.)
Version: 0.6.0
Path: /Users/rr26ua/.docker/cli-plugins/docker-sbom
scout: Docker Scout (Docker Inc.)
Version: v1.18.3
Path: /Users/rr26ua/.docker/cli-plugins/docker-scout
Server:
Containers: 0
Running: 0
Paused: 0
Stopped: 0
Images: 42
Server Version: 28.5.1
Storage Driver: overlayfs
driver-type: io.containerd.snapshotter.v1
Logging Driver: json-file
Cgroup Driver: cgroupfs
Cgroup Version: 2
Plugins:
Volume: local
Network: bridge host ipvlan macvlan null overlay
Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog
CDI spec directories:
/etc/cdi
/var/run/cdi
Discovered Devices:
cdi: docker.com/gpu=webgpu
Swarm: inactive
Runtimes: io.containerd.runc.v2 runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 05044ec0a9a75232cad458027ca83437aae3f4da
runc version: v1.2.5-0-g59923ef
init version: de40ad0
Security Options:
seccomp
Profile: builtin
cgroupns
Kernel Version: 6.10.14-linuxkit
Operating System: Docker Desktop
OSType: linux
Architecture: aarch64
CPUs: 12
Total Memory: 17.54GiB
Name: docker-desktop
ID: 16f9601d-bfa4-451a-b70a-dee4df4530e5
Docker Root Dir: /var/lib/docker
Debug Mode: false
HTTP Proxy: http.docker.internal:3128
HTTPS Proxy: http.docker.internal:3128
No Proxy: hubproxy.docker.internal
Labels:
com.docker.desktop.address=unix:///Users/rr26ua/Library/Containers/com.docker.docker/Data/docker-cli.sock
Experimental: false
Insecure Registries:
hubproxy.docker.internal:5555
::1/128
127.0.0.0/8
Live Restore Enabled: false
Default Address Pools:
Base: 172.16.0.0/12, Size: 24Diagnostics ID
2FE4CEFD-2D82-4B13-AE58-4D612D05FC79/20251027135322
Additional Info
No response