# UDP: bad checksum from 10.0.0.2:12345 to 10.0.0.1:53

- **ID:** `networking/udp-checksum-failure`
- **Domain:** networking
- **Category:** network_error
- **Verification:** ai_generated
- **Fix Rate:** 75%

## Root Cause

The UDP datagram received has an incorrect checksum, indicating corruption during transit, a faulty network interface, or software that generates invalid checksums.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| Linux kernel 5.15 | active | — | — |
| Linux kernel 6.1 | active | — | — |
| FreeBSD 13.2 | active | — | — |

## Workarounds

1. **Check network interface for errors: ethtool -S eth0 | grep -i error** (85% success)
   ```
   Check network interface for errors: ethtool -S eth0 | grep -i error
   ```
2. **Update NIC driver or firmware to resolve hardware-level checksum issues: ifconfig eth0 down && modprobe -r driver_name && modprobe driver_name && ifconfig eth0 up** (80% success)
   ```
   Update NIC driver or firmware to resolve hardware-level checksum issues: ifconfig eth0 down && modprobe -r driver_name && modprobe driver_name && ifconfig eth0 up
   ```

## Dead Ends

- **** — Disabling UDP checksum offloading (ethtool -K eth0 tx-checksumming off) may mask the issue but doesn't fix the root cause if the sender generates bad checksums. (75% fail)
- **** — Assuming it's a transient network issue and ignoring repeated occurrences can lead to data corruption in DNS responses or other UDP services. (80% fail)