2.2 KiB
resolv.conf — Original Broken Content
Source: Direct inspection of /etc/resolv.conf inside bridge-networked Docker container, 2026-02-13 Caption: Content of /etc/resolv.conf as found inside bridge-networked Docker containers before the daemon.json DNS fix. This file was generated by Docker from the host's /etc/resolv.conf (Unraid default) and listed two unreachable nameservers before the first reachable one. Extraction type: raw_table
File Content (Reconstructed from HISTORY.md)
nameserver 192.168.1.50
nameserver 169.254.24.117
nameserver 1.1.1.1
Nameserver Analysis
| Entry | IP | Role | Reachable from bridge container? | Notes |
|---|---|---|---|---|
| nameserver 1 | 192.168.1.50 | Technitium DNS (LAN IP) | No | Technitium listens here on host, but UDP responses from this IP are dropped by Docker NAT/conntrack for bridge container queries. Causes ~4-second timeout. |
| nameserver 2 | 169.254.24.117 | Docker embedded DNS (legacy) | No | Link-local address; not a valid DNS server in this configuration. Dead endpoint. Causes another ~4-second timeout. |
| nameserver 3 | 1.1.1.1 | Cloudflare public DNS | Yes | Actually reachable; responds quickly. But only reached after ~8 seconds of failed attempts at nameservers 1 and 2. |
Failure Mode
DNS resolution path for any query:
- Try 192.168.1.50:53 — wait ~4s — no response — timeout
- Try 169.254.24.117:53 — wait ~4s — no response — timeout
- Try 1.1.1.1:53 — response in <50ms — success
Total latency per query: ~8 seconds before the actual DNS response.
Incident Note
During debugging of this resolv.conf, the nanobot container edited this file and accidentally left only nameserver 192.168.1.50 (the broken entry), immediately destroying all DNS connectivity. Recovery required Makar to externally restart the nanobot container. This incident led to the hard rule encoded in C06 and H06: never write to /etc/resolv.conf inside a running container.
Post-Fix resolv.conf
After applying {"dns": ["172.17.0.1"]} to daemon.json and recreating containers:
nameserver 172.17.0.1
Single entry. Technitium reachable at this IP via docker0 bridge. ~2ms latency.