Manually assigning IP addresses to thousands of miners quickly becomes operationally unmanageable. Implementing Dynamic Host Configuration Protocol (DHCP) provides an automated, scalable solution for deploying and maintaining large fleets of mining devices. When miners are configured for DHCP (the default in most firmware), each device
broadcasts its unique MAC address at Layer 2 and requests an IP address lease from a DHCP server.
To maintain stability and predictability across a mining site, only one authoritative DHCP server should respond on each
Layer 2 broadcast domain. Redundant DHCP servers must be coordinated—typically via failover mechanisms or IP
helper configuration—to prevent duplicate address assignments or lease conflicts. A reliable DHCP and DNS
infrastructure ensures miners come online quickly, resolve pool addresses properly, and can be centrally managed
without manual intervention.
DHCP and Helper Addresses
In large-scale environments, mining racks are often distributed across multiple network segments or VLANs. Since
DHCP is a broadcast-based protocol, DHCP relay agents (commonly known as IP helpers on routers or layer-3 switches) must be configured to forward client requests to centralized DHCP servers.
- Configure a dedicated DHCP scope per VLAN or subnet, aligned with your rack or pod layout.
- Use IP helper-addresses on layer-3 interfaces (SVIs or routed ports) to forward UDP ports 67/68 traffic to the central DHCP server(s).
- Employ DHCP reservations for key infrastructure (controllers, monitoring hosts, or known miners) when fixed addressing is required.
- Implement DHCP failover or high-availability between servers to prevent lease service interruption.
- Log and monitor lease assignments—this data can be used for device inventory, security, and troubleshooting.
DHCP Security
Mining facilities are high-density environments, and network misconfigurations or unauthorized devices can cause widespread outages. Proper DHCP security controls protect address space integrity and minimize operational risk.
- Limit DHCP service to trusted interfaces only. Disable the service on uplinks or management networks where miners are not connected.
- Enable DHCP snooping on access switches. This feature enforces which ports can respond to DHCP requests and builds a trusted database of MAC-to-IP bindings.
- Pair DHCP snooping with Dynamic ARP Inspection (DAI) and IP Source Guard to prevent IP or ARP spoofing on the mining LAN.
- Isolate guest, management, and miner VLANs to prevent cross-network interference.
- Regularly back up the DHCP lease database and configuration to avoid recovery downtime.
DNS Security and Performance
DNS is critical for mining operations—miners must resolve pool domains, monitoring endpoints, and firmware update servers. Even brief DNS failures can cause hash-rate drops or disconnections across thousands of devices. This may seem obvious, but locally configured DNS servers are crucial.
- Deploy redundant local DNS caching resolvers within the mining facility. Miners should point to these resolvers, which in turn forward queries to upstream DNS servers or providers.
- Configure split-horizon DNS when internal services (like management dashboards or monitoring) share domain names with public pools.
- Enable DNSSEC validation on recursive resolvers to ensure integrity of upstream responses.
- Use short TTLs (30–300 seconds) for pool hostnames to accommodate failover or pool changes without long
- cache delays.
- Monitor resolver health, query volume, and response latency—high query failure rates often indicate network or upstream issues.
- Restrict external DNS access and enforce egress firewall policies to ensure miners cannot use arbitrary resolvers, which could expose them to malicious redirections. This will also take the load off the Firewall’s NAT table – reducing PAT entries by up to 5 per miner.
Conclusion
A disciplined DHCP and DNS design is essential for maintaining uptime, predictability, and security in large-scale Bitcoin mining operations. Implementing centralized management, proper segmentation, and strong security controls minimizes downtime and simplifies operational scaling as your deployment grows.
