LiteLLM / LiteLLM

LiteLLM Connection Refused Error — Proxy Misconfiguration

Fix LiteLLM proxy ConnectionRefusedError by verifying proxy process is running on expected host:port, resolving Docker network isolation, unsetting conflicting LITELLM_PORT env variable Includes evidence for LiteLLM troubleshooting demand.

Source-backed Last updated June 10, 2026 4 sources Needs local verification

Category: LiteLLM
Error signature: litellm.llms.custom_httpx.http_handler.HTTPHandler.post: Connection refused OR httpx.ConnectError: [Errno 111] Connection refused
Quick fix: Confirm the local service is running on the expected host and port, then retry the smallest request.
Updated: June 10, 2026
Verification status: Source-backed
Evidence: 4 public source URLs

Before you change production

This page includes public source URLs in the imported troubleshooting record. Compare those references with your version and environment before applying changes.

Reproduce the smallest failing action and save non-secret logs before changing configuration.
Check versions for LiteLLM, related SDKs, package managers, CI runners, and hosting providers.
Change one setting or dependency at a time, then rerun the same failing command or request.
Avoid destructive commands, credential rotation, billing changes, or security relaxations without a rollback plan.

What this error means

litellm.llms.custom_httpx.http_handler.HTTPHandler.post: Connection refused OR httpx.ConnectError: [Errno 111] Connection refused is a LiteLLM failure pattern reported for developers trying to fix litellm proxy connectionrefusederror by verifying proxy process is running on expected host:port, resolving docker network isolation, unsetting conflicting litellm_port env variable. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

Markaicode article (June 2026) documents that ConnectionRefusedError accounts for ~40% of all LiteLLM startup errors. Root causes are port mismatch, wrong host inside Docker (localhost vs host.docker.internal), and firewall/SELinux blocking port 4000. GitHub issue #27823 notes RouterRateLimitError masking underlying quota errors without Retry-After header. Category mapping: LiteLLM → LiteLLM.

Common causes

Markaicode article (June 2026) documents that ConnectionRefusedError accounts for ~40% of all LiteLLM startup errors. Root causes are port mismatch, wrong host inside Docker (localhost vs host.docker.internal), and firewall/SELinux blocking port 4000. GitHub issue #27823 notes RouterRateLimitError masking underlying quota errors without Retry-After header. Category mapping: LiteLLM → LiteLLM.

Quick fixes

Confirm the exact error signature matches litellm.llms.custom_httpx.http_handler.HTTPHandler.post: Connection refused OR httpx.ConnectError: [Errno 111] Connection refused.
Check the LiteLLM account, local tool state, and provider configuration involved in the failing workflow.
Confirm the local service is running on the expected host and port, then retry the smallest request.

Platform/tool-specific checks

Verify the command, editor, extension, or API client that produced the error.
Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

Capture the exact error message and the command, editor action, or request that triggered it.
Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
Review the source evidence below and compare it with your environment.
Apply one change at a time and rerun the smallest failing action.
Keep the working fix documented for the team or deployment environment.

How to prevent it

Keep provider/tool configuration documented.
Record non-secret diagnostics such as tool version, provider name, model name, and command path.
Add a lightweight check before CI or production workflows depend on the tool.

Diagnostic flow for this page

Match litellm.llms.custom_httpx.http_handler.HTTPHandler.post: Connection refused OR httpx.ConnectError: [Errno 111] Connection refused exactly before applying the quick fix.
Compare the failing environment with LiteLLM versions, account scope, provider settings, and deployment context.
Check the listed common causes in order, starting with the cause that best matches your logs.
Use the evidence status below to decide whether to confirm against public sources or official documentation.
Apply one reversible change, rerun the smallest failing action, and keep rollback notes.

FAQ

What does litellm.llms.custom_httpx.http_handler.HTTPHandler.post: Connection refused OR httpx.ConnectError: [Errno 111] Connection refused mean in LiteLLM?

litellm.llms.custom_httpx.http_handler.HTTPHandler.post: Connection refused OR httpx.ConnectError: [Errno 111] Connection refused indicates the workflow described by "LiteLLM Connection Refused Error — Proxy Misconfiguration" failed in a LiteLLM context. Start by confirming the exact signature and the component that emitted it.

What should I check first for litellm.llms.custom_httpx.http_handler.HTTPHandler.post: Connection refused OR httpx.ConnectError: [Errno 111] Connection refused?

Check whether this cause matches your environment: Markaicode article (June 2026) documents that ConnectionRefusedError accounts for ~40% of all LiteLLM startup errors. Root causes are port mismatch, wrong host inside Docker (localhost vs host.docker.internal), and firewall/SELinux blocking port 4000. GitHub issue #27823 notes RouterRateLimitError masking underlying quota errors without Retry-After header. Category mapping: LiteLLM → LiteLLM.

Is the litellm.llms.custom_httpx.http_handler.HTTPHandler.post: Connection refused OR httpx.ConnectError: [Errno 111] Connection refused guidance source-backed?

The "LiteLLM Connection Refused Error — Proxy Misconfiguration" page is labeled source-backed. It has 4 public source URLs from markaicode.com, github.com, so use that evidence status when deciding how much additional verification you need.

When should I avoid the quick fix for litellm.llms.custom_httpx.http_handler.HTTPHandler.post: Connection refused OR httpx.ConnectError: [Errno 111] Connection refused?

For "LiteLLM Connection Refused Error — Proxy Misconfiguration", avoid applying "Confirm the local service is running on the expected host and port, then retry the smallest request." when the error text differs, the affected version or provider is different, or the change would touch credentials, billing, DNS, production deploy settings, or irreversible data.

What should I collect before debugging litellm.llms.custom_httpx.http_handler.HTTPHandler.post: Connection refused OR httpx.ConnectError: [Errno 111] Connection refused?

For "LiteLLM Connection Refused Error — Proxy Misconfiguration", collect the failing LiteLLM command or request, non-secret configuration, versions, timestamps, request IDs when available, and the smallest reproduction that still triggers the signature.