Network Problems — Troubleshooting Guide

Symptoms

You are experiencing one or more of the following:

• Cannot find the miner's IP address on your network
• Miner's web UI is unreachable in a browser
• Network IP scanner does not list the miner
• Miner powers on normally (fans spin, LEDs light) but pool shows it offline
• Ethernet link lights are off on the miner or switch
• Miner was accessible before but stopped responding after a network change
• Web UI loads but shows "No pool connected" or pool connection errors

Quick Checks

1. Is the Ethernet cable plugged in? Check both ends -- at the miner and at the switch/router. The connectors should click firmly into place.
2. Are the link lights on? Look at the Ethernet port on the miner and the corresponding port on your switch/router. At least one LED (usually green or amber) should be lit or blinking. No lights = no physical link.
3. Is the router/switch powered on? Confirm your network equipment is working and other devices on the same network can access the internet.
4. Try a different Ethernet cable. Cables are cheap and frequently faulty. A known-good cable eliminates the most common physical cause.
5. Try a different switch/router port. Individual ports on switches can fail. Moving to a different port is a quick test.
6. Has the miner's IP address changed? If your network uses DHCP, the miner may have received a different IP address after a reboot or lease expiration.

Diagnostic Flowchart

Can't find miner on network
│
├─ Ethernet link lights ON?
│  ├─ NO (no lights on either end)
│  │  ├─ Try different cable → Lights come on? Bad cable.
│  │  ├─ Try different switch port → Lights come on? Bad port.
│  │  └─ Still no lights → Miner's Ethernet port may be damaged
│  │
│  └─ YES (lights on or blinking)
│     ├─ Can you ping the miner's last known IP?
│     │  ├─ YES → Miner is on the network. Try browser access.
│     │  │  ├─ Browser works → Miner is fine, pool config issue
│     │  │  └─ Browser fails → Wrong port or firewall blocking HTTP
│     │  │
│     │  └─ NO → IP has changed or miner has no IP
│     │     ├─ Scan network for new devices (nmap, IP scanner)
│     │     ├─ Check router DHCP lease table
│     │     ├─ Use IP reporter button (Antminer)
│     │     └─ Use WhatsMiner Tool (Whatsminer)
│     │
│     └─ Miner found but pool shows offline
│        ├─ DNS resolution working? Try pool IP directly
│        ├─ Firewall blocking outbound port? (3333, 443, etc.)
│        └─ ISP blocking mining traffic? Try alternate port

How to Find Your Miner's IP Address

If you have lost track of your miner's IP address, use one of these methods:

# Scan your local subnet for devices with port 80 open (web UI)
nmap -sn 192.168.1.0/24

# More detailed scan showing open ports and OS detection
nmap -sV -p 80,443,4028 192.168.1.0/24

Causes

1. Bad Ethernet Cable

Probability: Very High

Ethernet cables are the most common point of failure in miner network connectivity. Cables degrade from heat exposure near miners, can be physically damaged, and cheap cables may have manufacturing defects.

Symptoms specific to this cause:

• No link lights on either the miner or the switch
• Intermittent connectivity (miner appears and disappears from network)
• Slow web UI response or timeouts
• Link lights on but data transfer unreliable (packet loss)

Diagnosis:

Fix: Replace the cable with a quality Cat5e or Cat6 cable of appropriate length. Avoid cables longer than 100 meters (328 feet) -- this is the maximum specified length for Ethernet.

Prevention: Use quality cables. Route cables away from heat sources. Use cable management to prevent physical damage. Keep spare cables on hand.

2. DHCP Exhaustion or IP Conflict

Probability: High

If your DHCP server (router) has run out of available IP addresses, new devices (or devices renewing their lease) cannot get an IP address. Similarly, if two devices have the same static IP address, both will have connectivity problems.

Symptoms specific to this cause:

• Miner has link lights but no IP address
• Miner had a working IP but lost it after a network change
• Other new devices on the network also fail to get IP addresses
• Multiple miners came online at the same time and some got IPs while others did not

Diagnosis:

# Ping the IP address with the miner powered off
ping 192.168.1.50

# If something responds while the miner is off, another device has that IP

Fix: Expand the DHCP pool range in your router settings. Release expired leases. For large mining operations with many devices, use a proper DHCP server with a sufficiently large address pool. For IP conflicts, change one device's address.

Prevention: Use DHCP reservations (assign a fixed IP to each miner's MAC address through the router). This guarantees each miner always gets the same IP without the risk of conflicts. For large operations, plan your IP addressing scheme before deploying miners.

3. Wrong Subnet or VLAN

Probability: Medium

If the miner is on a different subnet or VLAN than your computer, you cannot reach it directly. This commonly happens when a miner is moved between network segments or when network infrastructure changes.

Symptoms specific to this cause:

• Miner has link lights and an IP address (visible in router DHCP table) but you cannot ping or access it from your computer
• Miner is on a different IP range than your computer (e.g., miner is 10.0.0.x and your computer is 192.168.1.x)
• The miner was working before a network infrastructure change

Diagnosis:

Compare your computer's IP address and subnet mask with the miner's IP address. They must be on the same subnet to communicate directly:

# Check your computer's IP
# Windows
ipconfig

# Mac/Linux
ifconfig
# or
ip addr

If your computer is 192.168.1.x and the miner is 192.168.0.x, they are on different subnets and cannot communicate without a router.

Fix: Move the miner to the same network segment as your management computer, or configure inter-VLAN routing. If the miner has a static IP on the wrong subnet, you may need to factory reset it to restore DHCP operation.

Prevention: Document your network topology. When moving miners between locations, verify the network subnet. Use DHCP for all miners unless you have a specific reason for static IPs.

4. Control Board Network IC Failure

Probability: Low

The Ethernet PHY chip or the SoC's network interface on the control board can fail, making the miner unable to communicate over the network. This is a hardware failure.

Symptoms specific to this cause:

• No link lights on the miner's Ethernet port, even with a known-good cable and switch port
• Miner powers on normally (fans spin, hashing LEDs blink) but has zero network
• Problem persists with multiple cables and switch ports
• The Ethernet port connector itself may show physical damage

Diagnosis:

# Check if the ethernet interface exists
ifconfig -a
# or
ip link show

# Check for driver errors
dmesg | grep -i eth

Fix: If the Ethernet PHY chip has failed, the control board needs component-level repair (PHY chip replacement) or full control board replacement. This is a professional repair task.

Prevention: Use surge protectors on both power and network connections. Lightning strikes and power surges can damage Ethernet PHY chips through the network cable.

5. Firewall or ISP Blocking Mining Traffic

Probability: Low-Medium

Some corporate networks, public networks, and even some ISPs block the ports used by mining pool protocols. The miner may have network connectivity (web UI works) but cannot reach the pool.

Symptoms specific to this cause:

• Miner's web UI is accessible and shows everything working except pool connection
• Pool status shows "Disconnected" or "Connection timeout"
• Miner log shows "Stratum connection failed" repeatedly
• Other miners on a different network (or the same miner on a different network) work fine

Diagnosis:

From a computer on the same network, test connectivity to your mining pool's port:

# Test pool connectivity
nc -zv stratum.braiins.com 3333
# Expected: Connection succeeded

# Try alternate ports if standard port is blocked
nc -zv stratum.braiins.com 443
nc -zv stratum.braiins.com 25

If the connection fails from your network but works from a different network (like a mobile hotspot), your network or ISP is blocking the traffic.

Fix: Try alternate pool ports (443, 8080, 25 are commonly used alternatives). Configure your firewall to allow outbound connections on the required ports. If your ISP is blocking mining traffic, use a VPN or contact your ISP about the restriction.

Prevention: When setting up a mining operation, test pool connectivity before deploying miners. Use pools that offer connections on common ports (443) that are less likely to be blocked.

6. Static IP Conflict

Probability: Low

If the miner was manually configured with a static IP address and that address conflicts with another device, or the static IP is on the wrong subnet, the miner will be unreachable.

Symptoms specific to this cause:

• Miner was previously configured with a static IP
• The network infrastructure was changed (new router, new subnet)
• The miner's static IP is no longer valid for the current network

Diagnosis:

If you know the miner's static IP, try connecting to it directly. If the subnet has changed and you cannot reach the miner, you will need to factory reset the network settings.

Fix: Factory reset the miner's network settings to restore DHCP (see the reset procedures above), or connect directly to the miner using a laptop with a manual IP in the same subnet as the miner's static IP. Then change the miner's network settings through the web UI.

Prevention: Use DHCP with reservations rather than static IP configuration on the miner itself. This way, the IP assignment is managed by the router and can be changed centrally without touching each miner.

When to Seek Professional Help

Contact a qualified network technician or repair service if:

• The miner's Ethernet port appears physically damaged
• You suspect the control board's network chip has failed
• You need to set up a network infrastructure for a large mining operation (VLANs, managed switches, dedicated subnets)
• Your ISP is blocking mining traffic and you cannot resolve it with port changes

Frequently Asked Questions

Q: Can I use Wi-Fi with my miner instead of Ethernet?

Most ASIC miners do not have built-in Wi-Fi. A few models and some custom firmware support USB Wi-Fi adapters, but this is not recommended for production mining. Wi-Fi is less reliable and has higher latency than Ethernet, which can lead to increased stale shares.

Q: Do I need a managed switch for my mining operation?

For small operations (less than 10 miners), an unmanaged gigabit switch is sufficient. For larger operations, managed switches with VLAN support, port monitoring, and SNMP are recommended for easier management and troubleshooting.

Q: My miner works on my home network but not at the mining facility. Why?

The most common reasons are: different subnet configuration, DHCP not available on the facility network, firewall rules blocking pool traffic, or the miner still has a static IP from the previous network. Reset network settings and ensure DHCP is available on the new network.

Q: How much bandwidth does a miner use?

ASIC miners use very little bandwidth -- typically 10-50 KB/s per miner. Even hundreds of miners can share a modest internet connection. The critical factor is latency and reliability, not bandwidth. A stable low-bandwidth connection is better than a fast but unreliable one.

Q: Can I access my miner remotely over the internet?

Not directly, and you should not expose the miner's web UI to the public internet (it has minimal security). For remote access, use a VPN to your mining network, or use a monitoring service that the miner pushes data to. Some custom firmware supports cloud-based monitoring dashboards.

Related Guides

• Miner Shows No Hashrate -- Network issues are a common cause of zero hashrate
• Firmware Corruption -- Network is needed for firmware updates
• Power Supply Issues -- Miner must be powered on to have network