ASIC Miner – DNS Resolution Failed

Override router DNS to 1.1.1.1 (Cloudflare) and 8.8.8.8 (Google) as secondary. Log into router admin at your gateway IP (192.168.1.1 or 192.168.0.1), find WAN / DHCP / Internet settings, switch DNS from Auto / ISP to manual, enter both addresses, save, reboot the router. Single highest-ROI change in this guide -- ends 60-70% of DNS issues on Canadian residential networks outright. Document what you changed before you change it; carrier support may ask.

Power-cycle the miner for 30 seconds. Full unplug at the PDU or breaker, not a soft reboot. Full power cycle clears any wedged resolver state in the miner's network stack and forces a fresh DHCP lease that picks up the new DNS you set in step 1. Soft reboots often reuse cached state and mask the fix.

Reboot the router after changing DNS. The DHCP server on most consumer routers only re-pushes DNS settings to clients on lease renewal. A router reboot forces every DHCP client to re-register and pick up the new resolver addresses cleanly. Rookie error: change DNS, don't reboot router, wonder why nothing changed.

Swap the pool URL to a raw IP as a temporary fix. From any working laptop, run `nslookup stratum.yourpool.com` to get the current backend IP. Enter that IP in the miner's pool config instead of the hostname. Save, reboot miner. Mining resumes inside 60 seconds. This is a band-aid -- pool backend IPs rotate, and your miner will fail again in hours or days -- but it gets you hashing while you diagnose the DNS path properly.

Check for firmware updates. Bitmain: support.bitmain.com/downloads. Whatsminer: manufacturer portal. Bitaxe: d-central.tech -- we stock and support the latest AxeOS builds for every Bitaxe variant, we pioneered the Mesh Stand and Hex heatsink, so we run the current firmware on our own bench. A known-buggy network stack in the firmware resolves once you update. Verify your hardware revision before flashing -- wrong firmware bricks the control board.

Pin DNS at the miner itself with a static IP. In the miner's network panel: switch from DHCP to static IP, assign a LAN-friendly address outside your router's DHCP pool, gateway = your router IP, subnet = 255.255.255.0, DNS 1 = 1.1.1.1, DNS 2 = 8.8.8.8. Save, reboot. Bypasses DHCP and ISP DNS entirely -- the two most common external failure modes -- and makes the miner reachable at a predictable address for SSH and monitoring. Best permanent fix for any production mining rig.

Set a long DHCP reservation if you prefer DHCP over static. In router admin, find the miner's MAC address under the DHCP client list, create a reservation mapping that MAC to a fixed IP, and verify the router's DHCP scope pushes DNS as 1.1.1.1 / 8.8.8.8. Lease time to 86400 seconds (24 hours) or longer. This gives you the predictability of static without editing the miner itself -- useful for fleets.

Disable router-side `Secure DNS` / DoH / DoT. Look under Security, WAN, or Privacy settings for `DNS-over-HTTPS`, `Encrypted DNS`, `Cloudflare Secure DNS`, `NextDNS`, or `Privacy DNS`. Disable it for the miner's VLAN or globally. Stock Bitmain / Whatsminer / Avalon / basic Bitaxe firmware speak plain UDP/53; they cannot negotiate DoH or DoT. If the router forces DoH-only outbound, the miner is dead. DoH is fine for your laptop -- not for an ASIC mining stack.

Disable AiProtection / Armor / Eero Secure / Trend Micro on the miner VLAN. These features inject themselves into the DNS path, maintain their own block lists, and have been observed filtering mining-pool domains as `cryptojacking`. If your router has a dedicated security subscription running, exempt the miner's MAC/IP or create a VLAN with the feature disabled. Your mining rig does not need AI-powered threat prevention.

Whitelist pool domains on any Pi-hole / AdGuard / pfBlockerNG appliance. In the filtering appliance admin: add explicit allow rules for public-pool.io, solo.ckpool.org, stratum.braiins.com, us-east.stratum.slushpool.com, us.ocean.xyz, and any other pool domains you use. Community blocklists like OISD and StevenBlack's hosts file have historically flagged mining pool domains as adware or cryptojacking -- explicit whitelisting makes the filter's intent clear.

SSH into the miner and inspect `/etc/resolv.conf` directly. Stock Bitmain / DCENT_OS / Braiins OS+ / LuxOS / Vnish all expose resolv.conf via SSH. Read it: `cat /etc/resolv.conf`. You should see `nameserver 1.1.1.1` and `nameserver 8.8.8.8` or equivalents. If it's empty, or shows a stale router IP, or contains only an unreachable IPv6 resolver, the miner's resolver config is the root cause. On stock Bitmain, resolv.conf is rewritten at boot from the network panel -- fix it there, not in the file directly.

VLAN-isolate the miner fleet with a clean DNS path. Dedicated VLAN on a managed switch (MikroTik, TP-Link Omada, UniFi) with a simple egress firewall rule: permit UDP/53 to 1.1.1.1 and 8.8.8.8 only, permit TCP/3333, TCP/4334, TCP/443 to pool CIDRs, UDP/123 for NTP, deny everything else. No AI-protection, no QoS, no DoH interception, no parental controls. Three categories of DNS pathology collapse into one clean path. Cheap gear from a $40 MikroTik hEX scales to hundreds of miners.

Flash DCENT_OS on Antminer hardware for a modern resolver path and real log output. DCENT_OS is D-Central's own open-source Antminer firmware -- built by Mining Hackers for Mining Hackers, maintained in public on GitHub. Saner network stack than stock Bitmain, exposes DNS failure reasons directly in the log (stock Bitmain often just says `cgminer: failure to initialize pool`), supports static DNS pinning cleanly in its network panel. Stratum V2 client-side and per-chip HW% as bonuses. Landing at d-central.tech/dcent-os, source at github.com/DCentralTech/DCENT_OS. Alternatives: Braiins OS+, LuxOS, Vnish. Not for Whatsminer / Avalon / Innosilicon / Bitaxe / Goldshell / Iceriver.

Run a local caching resolver on your LAN. Raspberry Pi 3/4/5 or a small x86 box running Unbound or dnsmasq as a caching-only resolver, upstream to 1.1.1.1 + 8.8.8.8 + 9.9.9.9. Point every miner's static DNS config at the Pi's IP. Resolver latency drops to sub-millisecond for cached names, pool-domain lookups survive a Cloudflare outage transparently, and you get a single pane of glass for DNS logs across the fleet. Cost: $35 + SD card.

Capture a failed DNS query with tcpdump for definitive evidence. From a Linux / macOS / WSL machine on the same LAN: `sudo tcpdump -i <iface> -n port 53 and host <miner-IP>`. Let it run while you trigger the error. Three outcomes: (a) no query leaves the miner -- resolver wedged, reflash firmware; (b) query goes out, no response -- upstream silently failing, swap resolver; (c) query goes out, NXDOMAIN or SERVFAIL returns -- resolver is working but cannot answer, try a different upstream. Collapses a week of guessing into ten minutes of evidence.

Stop DIY when the miner can neither ping a numeric IP nor SSH in after a full firmware reflash. That's no longer a DNS problem -- that's a control-board-level network stack failure, a dead Ethernet PHY, or a corrupted eMMC holding a broken network driver. Ship to D-Central. We test on a programmable bench network with a known-good resolver; if the fault clears on our bench, you had a LAN-side issue and we'll tell you, saving you the repair fee beyond diagnostics. Book ASIC Repair at d-central.tech/services/asic-repair/. Turnaround 5-10 business days.

Ship safely for repair. Anti-static bag the control board or the whole miner. Double-box with >=5 cm foam on every side. Include a written note: exact log lines, what you already tried (DNS override, static IP pinning, firmware reflash, VLAN isolation), screenshots of your tcpdump capture if you got one, the pool URLs you were trying to reach, and your firmware version. Diagnostic time is billable -- a good repair note cuts your quote materially. Stripped-bare symptoms save us and you money.