Fedora 43 DNF Repository Metadata Download Failure Report

1. Problem Description

Running sudo dnf upgrade --refresh failed with a 403 Forbidden error when attempting to fetch metadata from the Tsinghua University (TUNA) mirror for Fedora 43.

Error Message:

Status code: 403 for https://mirrors.tuna.tsinghua.edu.cn/fedora/updates/43/Everything/x86_64/repodata/... Failed to download metadata for repository "updates": Cannot download, all mirrors were already tried without success.

2. Root Cause Analysis

The issue was localized to the Tsinghua (TUNA) mirror station. Specifically, the DNF client was unable to access required metadata files (repomd.xml and associated blobs) because the server responded with a 403 status code. This typically indicates synchronization issues on the mirror server or temporary access restrictions for specific repository versions (Fedora 43).

3. Solution

The core strategy was to switch from a hardcoded baseurl (pointing directly to the TUNA mirror) back to the official Fedora metalink system. This system allows the DNF client to automatically discover and use the most reliable and geographically close mirrors from the global Fedora mirror network, bypassing the problematic TUNA mirror.

Steps Taken:

1. Repository Configuration Adjustment:
2. Modified /etc/yum.repos.d/fedora.repo and /etc/yum.repos.d/fedora-updates.repo.
3. Commented out the lines starting with baseurl=https://mirrors.tuna.tsinghua.edu.cn.

4. Enabled the official metalink lines by removing the # prefix.

5. Cache Refresh:

6. Executed sudo dnf clean all to remove stale/corrupted metadata.
7. Executed sudo dnf makecache --refresh to rebuild the cache using the new metalink configuration.

4. Verification & Status

After the configuration change, dnf check-update successfully contacted the Fedora infrastructure, retrieved metadata from working mirrors, and identified over 100 pending updates.

Current Status: Resolved. System is ready for sudo dnf upgrade.

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Report Generated: 2026-03-09