No network connectivity between bridge networks using published port, with userland-proxy disabled

### Description

It is not possible to access an exposed and published port of a container within another container if both containers are not in the same docker network.

Previous issue #38784 was closed but problem still exists.

### Reproduce

This example uses `192.168.122.178` for the servers external IP address. Change this address as necessary.

1. Example [docker-compose.yaml](https://github.com/user-attachments/files/22094888/docker-compose.yaml)
2. `docker compose up -d exposed`
3. `curl -s -v http://192.168.122.178`
4. `docker compose up client`

### Expected behavior

In step 4, the nginx welcome page should be outputted, like in step 3.

### docker version

```bash
Client: Docker Engine - Community
 Version:           28.3.3
 API version:       1.51
 Go version:        go1.24.5
 Git commit:        980b856
 Built:             Fri Jul 25 11:34:09 2025
 OS/Arch:           linux/amd64
 Context:           default

Server: Docker Engine - Community
 Engine:
  Version:          28.3.3
  API version:      1.51 (minimum version 1.24)
  Go version:       go1.24.5
  Git commit:       bea959c
  Built:            Fri Jul 25 11:34:09 2025
  OS/Arch:          linux/amd64
  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:        de40ad0
```

### docker info

```bash
Client: Docker Engine - Community
 Version:    28.3.3
 Context:    default
 Debug Mode: false
 Plugins:
  compose: Docker Compose (Docker Inc.)
    Version:  v2.39.1
    Path:     /usr/libexec/docker/cli-plugins/docker-compose

Server:
 Containers: 2
  Running: 1
  Paused: 0
  Stopped: 1
 Images: 5
 Server Version: 28.3.3
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: systemd
 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
 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:
  apparmor
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 6.8.0-79-generic
 Operating System: Ubuntu 24.04.3 LTS
 OSType: linux
 Architecture: x86_64
 CPUs: 2
 Total Memory: 3.824GiB
 Name: test
 ID: 4bf440ea-a59a-4dc7-966d-b4bab706671f
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Experimental: false
 Insecure Registries:
  ::1/128
  127.0.0.0/8
 Live Restore Enabled: false
```

### Additional Info

**/etc/docker/daemon.json**

```json
{
    "userland-proxy": false
}
```

**check-config.sh**

```
warning: /proc/config.gz does not exist, searching other paths for kernel config ...
info: reading kernel config from /boot/config-6.8.0-79-generic ...

Generally Necessary:
- cgroup hierarchy: cgroupv2
  Controllers:
  - cpu: available
  - cpuset: available
  - io: available
  - memory: available
  - pids: available
- apparmor: enabled and tools installed
- CONFIG_NAMESPACES: enabled
- CONFIG_NET_NS: enabled
- CONFIG_PID_NS: enabled
- CONFIG_IPC_NS: enabled
- CONFIG_UTS_NS: enabled
- CONFIG_CGROUPS: enabled
- CONFIG_CGROUP_CPUACCT: enabled
- CONFIG_CGROUP_DEVICE: enabled
- CONFIG_CGROUP_FREEZER: enabled
- CONFIG_CGROUP_SCHED: enabled
- CONFIG_CPUSETS: enabled
- CONFIG_MEMCG: enabled
- CONFIG_KEYS: enabled
- CONFIG_VETH: enabled (as module)
- CONFIG_BRIDGE: enabled (as module)
- CONFIG_BRIDGE_NETFILTER: enabled (as module)
- CONFIG_IP_NF_FILTER: enabled (as module)
- CONFIG_IP_NF_MANGLE: enabled (as module)
- CONFIG_IP_NF_TARGET_MASQUERADE: enabled (as module)
- CONFIG_IP6_NF_FILTER: enabled (as module)
- CONFIG_IP6_NF_MANGLE: enabled (as module)
- CONFIG_IP6_NF_TARGET_MASQUERADE: enabled (as module)
- CONFIG_NETFILTER_XT_MATCH_ADDRTYPE: enabled (as module)
- CONFIG_NETFILTER_XT_MATCH_CONNTRACK: enabled (as module)
- CONFIG_NETFILTER_XT_MATCH_IPVS: enabled (as module)
- CONFIG_NETFILTER_XT_MARK: enabled (as module)
- CONFIG_IP_NF_RAW: enabled (as module)
- CONFIG_IP_NF_NAT: enabled (as module)
- CONFIG_NF_NAT: enabled (as module)
- CONFIG_IP6_NF_RAW: enabled (as module)
- CONFIG_IP6_NF_NAT: enabled (as module)
- CONFIG_NF_NAT: enabled (as module)
- CONFIG_POSIX_MQUEUE: enabled
- CONFIG_CGROUP_BPF: enabled

Optional Features:
- CONFIG_USER_NS: enabled
- CONFIG_SECCOMP: enabled
- CONFIG_SECCOMP_FILTER: enabled
- CONFIG_CGROUP_PIDS: enabled
    (cgroup swap accounting is currently enabled)
- CONFIG_BLK_CGROUP: enabled
- CONFIG_BLK_DEV_THROTTLING: enabled
- CONFIG_CGROUP_PERF: enabled
- CONFIG_CGROUP_HUGETLB: enabled
- CONFIG_NET_CLS_CGROUP: enabled (as module)
- CONFIG_CGROUP_NET_PRIO: enabled
- CONFIG_CFS_BANDWIDTH: enabled
- CONFIG_FAIR_GROUP_SCHED: enabled
- CONFIG_IP_NF_TARGET_REDIRECT: enabled (as module)
- CONFIG_IP_VS: enabled (as module)
- CONFIG_IP_VS_NFCT: enabled
- CONFIG_IP_VS_PROTO_TCP: enabled
- CONFIG_IP_VS_PROTO_UDP: enabled
- CONFIG_IP_VS_RR: enabled (as module)
- CONFIG_SECURITY_SELINUX: enabled
- CONFIG_SECURITY_APPARMOR: enabled
- CONFIG_NFT_CT: enabled (as module)
- CONFIG_NFT_FIB_IPV4: enabled (as module)
- CONFIG_NFT_FIB_IPV6: enabled (as module)
- CONFIG_NFT_FIB: enabled (as module)
- CONFIG_NFT_MASQ: enabled (as module)
- CONFIG_NFT_NAT: enabled (as module)
- CONFIG_NF_TABLES: enabled (as module)
- CONFIG_EXT4_FS: enabled
- CONFIG_EXT4_FS_POSIX_ACL: enabled
- CONFIG_EXT4_FS_SECURITY: enabled
- Network Drivers:
  - "bridge":
    - sysctl net.ipv4.ip_forward: enabled
    - sysctl net.ipv6.conf.all.forwarding: disabled
    - sysctl net.ipv6.conf.default.forwarding: disabled
  - "overlay":
    - CONFIG_VXLAN: enabled (as module)
    - CONFIG_BRIDGE_VLAN_FILTERING: enabled
      Optional (for encrypted networks):
      - CONFIG_CRYPTO: enabled
      - CONFIG_CRYPTO_AEAD: enabled
      - CONFIG_CRYPTO_GCM: enabled
      - CONFIG_CRYPTO_SEQIV: enabled
      - CONFIG_CRYPTO_GHASH: enabled
      - CONFIG_XFRM: enabled
      - CONFIG_XFRM_USER: enabled (as module)
      - CONFIG_XFRM_ALGO: enabled (as module)
      - CONFIG_INET_ESP: enabled (as module)
      - CONFIG_NETFILTER_XT_MATCH_BPF: enabled (as module)
  - "ipvlan":
    - CONFIG_IPVLAN: enabled (as module)
  - "macvlan":
    - CONFIG_MACVLAN: enabled (as module)
    - CONFIG_DUMMY: enabled (as module)
  - "ftp,tftp client in container":
    - CONFIG_NF_NAT_FTP: enabled (as module)
    - CONFIG_NF_CONNTRACK_FTP: enabled (as module)
    - CONFIG_NF_NAT_TFTP: enabled (as module)
    - CONFIG_NF_CONNTRACK_TFTP: enabled (as module)
- Storage Drivers:
  - "btrfs":
    - CONFIG_BTRFS_FS: enabled (as module)
    - CONFIG_BTRFS_FS_POSIX_ACL: enabled
  - "overlay":
    - CONFIG_OVERLAY_FS: enabled (as module)
  - "zfs":
    - /dev/zfs: present
    - zfs command: missing
    - zpool command: missing

Limits:
- /proc/sys/kernel/keys/root_maxkeys: 1000000
```

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No network connectivity between bridge networks using published port, with userland-proxy disabled #50876

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No network connectivity between bridge networks using published port, with userland-proxy disabled #50876

Description

Description

Reproduce

Expected behavior

docker version

docker info

Additional Info

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

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