[5/n] IPv6 support: Add IPv6 localhost support and eliminate 0.0.0.0 server bindings #59852

Yicheng-Lu-llll · 2026-01-05T14:25:12Z

Description

This PR adds IPv6 localhost support and improves server binding security by eliminating 0.0.0.0 bindings.

goal

Avoid hardcoding 127.0.0.1, which breaks IPv6 support.
Avoid proactively using 0.0.0.0, which is insecure.

Server side

For local-only servers, bind to localhost (resolved via GetLocalhostIP()/ get_localhost_ip(); IPv4/IPv6).
For servers that need cross-node communication, bind to the node IP instead of 0.0.0.0.
If the user explicitly configures a bind address, always respect the user setting.

Client side

Use localhost when connecting to local-only servers (resolved via get_localhost_ip()).
Use the node IP when connecting to servers that require cross-node communication.

Note：

0.0.0.0 → node_ip related changes this PR made：

GCS Server: 0.0.0.0 → node_ip
Raylet gRPC: 0.0.0.0 → node_ip
Core Worker gRPC: 0.0.0.0 → node_ip
Object Manager: 0.0.0.0 → node_ip
Remote Python Debugger: 0.0.0.0 → node_ip
Ray Client Server already passed the node IP before this PR, but its default --host was 0.0.0.0. This PR changed it to localhost.
Dashboard Server by default binds to localhost. This PR just updated the documentation to suggest using node IP instead of 0.0.0.0 for remote access.
Non-Ray-core components (e.g., Serve): This PR keeps them binding to all interfaces as before, but replaced hardcoded 0.0.0.0 with get_all_interfaces_ip() to handle IPv6 (returns :: for IPv6 environments).

Related issues

Link related issues: "Fixes #1234", "Closes #1234", or "Related to #1234".

Additional information

Optional: Add implementation details, API changes, usage examples, screenshots, etc.

gemini-code-assist

Code Review

This pull request is a significant and well-executed step towards full IPv6 support in Ray. It systematically replaces hardcoded IPv4 localhost addresses with a dynamic get_localhost_ip() function and eliminates insecure 0.0.0.0 bindings in favor of specific IP address bindings for gRPC servers. The changes are extensive, touching many parts of the codebase in both Python and C++, and appear to be correct and consistent. I have one suggestion for src/ray/util/network_util.cc to improve performance and code consistency by caching the result of get_localhost_ip. Overall, this is a high-quality contribution that improves Ray's networking capabilities and security posture.

src/ray/util/network_util.cc

Yicheng-Lu-llll · 2026-01-06T03:37:39Z

src/ray/gcs/gcs_server.cc

      rpc_server_(config.grpc_server_name,
                  config.grpc_server_port,
-                  config.node_ip_address == "127.0.0.1",
+                  config.node_ip_address,


Previously, this argument was listen_to_localhost_only. If it was true, we used 127.0.0.1; if not, we used 0.0.0.0.

After this PR, the argument is bind_address, so we now directly pass config.node_ip_address. If it is localhost, the behavior remains the same; if it is not, we change the binding from 0.0.0.0 to the node IP.

There are many similar changes in this PR following this pattern.

edoakes · 2026-01-06T23:20:15Z

@sampan-s-nayak can you help review pls?

edoakes

Mostly LGTM, just some minor nits

edoakes · 2026-01-07T15:55:56Z

python/ray/_common/network_utils.py

+    get_all_interfaces_ip as _get_all_interfaces_ip,
+    get_localhost_ip as _get_localhost_ip,


hm what is the point of this?

if you want to "alias" the imports, I believe you can simply do from ray._raylet import get_localhost_ip and others can do from network_utils import get_localhost_ip (it'll be in the global namespace of network_utils)

Makes sense, thank you! Fixed here: c8b4bb8

edoakes · 2026-01-07T15:57:48Z

python/ray/_private/ray_constants.py

 RAY_DASHBOARD_STARTUP_TIMEOUT_S = env_integer("RAY_DASHBOARD_STARTUP_TIMEOUT_S", 60)

-DEFAULT_DASHBOARD_IP = "127.0.0.1"
+DEFAULT_DASHBOARD_IP = get_localhost_ip()


this file is currently constants & env vars, so adding a dynamic lookup that interacts with the OS/network interfaces doesn't sit well with me. can we replace instances of DEFAULT_DASHBOARD_IP with a call to the util function directly instead?

Trade-off is losing a single point of change, especially since these are used as function parameter defaults. Same pattern exists for Serve's DEFAULT_HTTP_HOST. That said, fair point - replaced with direct calls:92799f1

edoakes · 2026-01-08T00:04:50Z

there are some merge conflicts

Signed-off-by: yicheng <yicheng@anyscale.com>

…ip() Signed-off-by: yicheng <yicheng@anyscale.com>

edoakes

LGTM. Kicked off premerge, lmk when passing

Signed-off-by: yicheng <yicheng@anyscale.com>

….0.1 in test_reporter_dashboard_and_runtime_env_agent Signed-off-by: yicheng <yicheng@anyscale.com>

…0.0.0.0 server bindings (ray-project#59852)" This reverts commit 60bb749.

…0.0.0.0 server bindings (ray-project#59852)" This reverts commit 60bb749. Signed-off-by: zac <zac@anyscale.com>

…0.0.0.0 server bindings (ray-project#59852)" This reverts commit 60bb749.

#60012) ## Description Reverting #59852 as it causes release test infra to fail. We need to update the infra to jive with the new port discovery settings properly. ## Related issues > Link related issues: "Fixes #1234", "Closes #1234", or "Related to #1234". ## Additional information Example failing build: https://buildkite.com/ray-project/release/builds/74681#

…server bindings (ray-project#59852) ## Description This PR adds IPv6 localhost support and improves server binding security by eliminating 0.0.0.0 bindings. ### goal - Avoid hardcoding 127.0.0.1, which breaks IPv6 support. - Avoid proactively using 0.0.0.0, which is insecure. ##### Server side - For local-only servers, bind to localhost (resolved via GetLocalhostIP()/ get_localhost_ip(); IPv4/IPv6). - For servers that need cross-node communication, bind to the node IP instead of 0.0.0.0. - If the user explicitly configures a bind address, always respect the user setting. ##### Client side - Use localhost when connecting to local-only servers (resolved via get_localhost_ip()). - Use the node IP when connecting to servers that require cross-node communication. #### Note： `0.0.0.0 → node_ip` related changes this PR made： - GCS Server: `0.0.0.0 → node_ip` - Raylet gRPC: `0.0.0.0 → node_ip` - Core Worker gRPC: `0.0.0.0 → node_ip` - Object Manager: `0.0.0.0 → node_ip` - Remote Python Debugger: `0.0.0.0 → node_ip` - Ray Client Server already passed the node IP before this PR, but its default `--host` was 0.0.0.0. This PR changed it to localhost. - Dashboard Server by default binds to localhost. This PR just updated the documentation to suggest using node IP instead of 0.0.0.0 for remote access. - Non-Ray-core components (e.g., Serve): This PR keeps them binding to all interfaces as before, but replaced hardcoded 0.0.0.0 with `get_all_interfaces_ip()` to handle IPv6 (returns :: for IPv6 environments). ## Related issues > Link related issues: "Fixes ray-project#1234", "Closes ray-project#1234", or "Related to ray-project#1234". ## Additional information > Optional: Add implementation details, API changes, usage examples, screenshots, etc. --------- Signed-off-by: yicheng <yicheng@anyscale.com> Co-authored-by: yicheng <yicheng@anyscale.com> Signed-off-by: jasonwrwang <jasonwrwang@tencent.com>

ray-project#60012) ## Description Reverting ray-project#59852 as it causes release test infra to fail. We need to update the infra to jive with the new port discovery settings properly. ## Related issues > Link related issues: "Fixes ray-project#1234", "Closes ray-project#1234", or "Related to ray-project#1234". ## Additional information Example failing build: https://buildkite.com/ray-project/release/builds/74681# Signed-off-by: jasonwrwang <jasonwrwang@tencent.com>

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Yicheng-Lu-llll force-pushed the ipv6-localhost branch 4 times, most recently from 89703b9 to 1d303e8 Compare January 6, 2026 03:08

Yicheng-Lu-llll commented Jan 6, 2026

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Yicheng-Lu-llll force-pushed the ipv6-localhost branch from 1d303e8 to 7cbcc28 Compare January 6, 2026 05:39

Yicheng-Lu-llll marked this pull request as ready for review January 6, 2026 06:04

Yicheng-Lu-llll requested review from a team, edoakes and jjyao as code owners January 6, 2026 06:04

Yicheng-Lu-llll added the core Issues that should be addressed in Ray Core label Jan 6, 2026

ray-gardener bot added the docs An issue or change related to documentation label Jan 6, 2026

edoakes reviewed Jan 7, 2026

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Yicheng-Lu-llll force-pushed the ipv6-localhost branch from efb52e9 to c8b4bb8 Compare January 7, 2026 23:31

yicheng added 3 commits January 8, 2026 00:49

add IPv6 localhost support and eliminate 0.0.0.0 server bindings

93b6dae

Signed-off-by: yicheng <yicheng@anyscale.com>

simplify network_utils

c4364f9

Signed-off-by: yicheng <yicheng@anyscale.com>

replace DEFAULT_DASHBOARD_IP && DEFAULT_HTTP_HOST with get_localhost_…

d6413d4

…ip() Signed-off-by: yicheng <yicheng@anyscale.com>

Yicheng-Lu-llll force-pushed the ipv6-localhost branch from 92799f1 to d6413d4 Compare January 8, 2026 00:51

edoakes added the go add ONLY when ready to merge, run all tests label Jan 8, 2026

edoakes approved these changes Jan 8, 2026

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yicheng added 2 commits January 8, 2026 02:22

fix lint

afd4c70

Signed-off-by: yicheng <yicheng@anyscale.com>

fix test added after rebase:use node.node_ip_address instead of 127.0…

7f4391e

….0.1 in test_reporter_dashboard_and_runtime_env_agent Signed-off-by: yicheng <yicheng@anyscale.com>

edoakes merged commit 60bb749 into ray-project:master Jan 8, 2026
6 checks passed

ZacAttack added a commit to ZacAttack/ray that referenced this pull request Jan 9, 2026

Revert "[5/n] IPv6 support: Add IPv6 localhost support and eliminate …

4862986

…0.0.0.0 server bindings (ray-project#59852)" This reverts commit 60bb749.

ZacAttack mentioned this pull request Jan 9, 2026

testing Revert "[5/n] IPv6 support: Add IPv6 localhost support and eliminate … #60003

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ZacAttack added a commit to ZacAttack/ray that referenced this pull request Jan 9, 2026

Revert "[5/n] IPv6 support: Add IPv6 localhost support and eliminate …

e808892

…0.0.0.0 server bindings (ray-project#59852)" This reverts commit 60bb749. Signed-off-by: zac <zac@anyscale.com>

ZacAttack added a commit to ZacAttack/ray that referenced this pull request Jan 9, 2026

Revert "[5/n] IPv6 support: Add IPv6 localhost support and eliminate …

3978626

…0.0.0.0 server bindings (ray-project#59852)" This reverts commit 60bb749. Signed-off-by: zac <zac@anyscale.com>

ZacAttack mentioned this pull request Jan 9, 2026

Revert #59852 "[5/n] IPv6 support: Add IPv6 localhost support and eliminate server 0.0.0.0 bindings" #60010

Closed

ZacAttack added a commit to ZacAttack/ray that referenced this pull request Jan 9, 2026

Revert "[5/n] IPv6 support: Add IPv6 localhost support and eliminate …

c0411d0

…0.0.0.0 server bindings (ray-project#59852)" This reverts commit 60bb749.

ZacAttack added a commit to ZacAttack/ray that referenced this pull request Jan 9, 2026

Revert "[5/n] IPv6 support: Add IPv6 localhost support and eliminate …

284391d

…0.0.0.0 server bindings (ray-project#59852)" This reverts commit 60bb749.

ZacAttack mentioned this pull request Jan 9, 2026

Revert "[5/n] IPv6 support: Add IPv6 localhost support and eliminate … #60012

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Yicheng-Lu-llll mentioned this pull request Jan 10, 2026

[6/n][Core] Add IPv6 localhost and all-interfaces support #60023

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[5/n] IPv6 support: Add IPv6 localhost support and eliminate 0.0.0.0 server bindings #59852

[5/n] IPv6 support: Add IPv6 localhost support and eliminate 0.0.0.0 server bindings #59852

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		get_all_interfaces_ip as _get_all_interfaces_ip,
		get_localhost_ip as _get_localhost_ip,

[5/n] IPv6 support: Add IPv6 localhost support and eliminate 0.0.0.0 server bindings #59852

[5/n] IPv6 support: Add IPv6 localhost support and eliminate 0.0.0.0 server bindings #59852

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Description

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Server side

Client side

Note：

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