Pool Connection Failed: Common Errors and Solutions

Learn how to diagnose and fix common PECPool connection errors, including Pool Dead, Socket Connect Failed, DNS Error, Authorization Failed, Connection Refused, Network Unreachable, No Shares, and repeated disconnections. This guide covers stratum addresses, ports, worker settings, DNS, firewalls, routing, miner logs, and backup pool configuration.

A Pool Connection Failed error means that an ASIC miner cannot establish or maintain a working connection with the configured PECPool stratum server.

The miner may still be powered on, its fans may be running, and its local interface may remain accessible. However, if it cannot receive mining jobs or submit valid shares, the worker will eventually appear Offline in the PECPool panel and will not generate effective mining contribution.

Pool connection failures are commonly caused by:

• An incorrect stratum address
• An incorrect or blocked port
• DNS resolution problems
• An incorrect mining account or worker name
• Internet or routing instability
• Firewall or ISP restrictions
• Miner firmware problems
• Incorrect network settings

This guide explains the most common PECPool connection errors and provides a structured troubleshooting process for Antminer, WhatsMiner, and other compatible Bitcoin SHA-256 ASIC miners.

How a Normal Pool Connection Works

Before troubleshooting, it is helpful to understand the normal connection process.

1. The ASIC miner starts and initializes its control board and hashboards.
2. The miner resolves the PECPool stratum hostname through DNS.
3. The miner opens a TCP connection to the configured server and port.
4. The miner submits its mining account and worker information.
5. PECPool authenticates the worker.
6. PECPool sends Bitcoin mining jobs to the miner.
7. The miner calculates and submits mining shares.
8. PECPool validates the submitted shares.
9. The worker appears Online after valid shares are received.

A failure at any of these stages can prevent successful mining.

Start by Checking the Pool Status

Open the miner's local management interface and find the pool or mining status page.

Depending on the miner and firmware, this section may be called:

• Miner Status
• Mining Status
• Pool Status
• Dashboard
• CGMiner Status
• Overview

Check:

• The active Pool URL
• The pool connection status
• The configured worker name
• Accepted shares
• Rejected shares
• Last share time
• Local and average hashrate
• Miner uptime

A successful connection may be displayed as:

• Alive
• Active
• Connected
• Working

A failed connection may be displayed as:

• Dead
• Disconnected
• Failed
• Inactive
• Connecting
• Retrying

Official PECPool Bitcoin Stratum Servers

Always use an official PECPool Bitcoin stratum hostname and a supported port.

Region	Server	Available Ports
Global	btc.pecpool.com	3333, 443, 25
United States	btc-us.pecpool.com	3333, 443, 25
Europe	btc-eu.pecpool.com	3333, 443, 25
Russia	btc-ru.pecpool.com	3333, 443, 25
Asia	btc-as.pecpool.com	8443, 443, 25
Iran	btc-ir.pecpool.com	8443, 443, 25
Iran Alternative	btc.pecpool.cc	8443, 443, 25

The complete Pool URL must use this format:

stratum+tcp://server-address:port

Example:

stratum+tcp://btc-eu.pecpool.com:3333

Do Not Use a Website Address as the Pool URL

The PECPool website and control panel addresses cannot be used as mining stratum addresses.

Incorrect:

https://pecpool.com
https://cp.pecpool.com
https://cp.pecpool.cc

Correct:

stratum+tcp://btc.pecpool.com:3333

ASIC miners require a stratum server address, not a normal website URL.

Common Pool Connection Errors

Error	Common Meaning	Primary Checks
Pool Dead	The miner cannot establish or maintain the pool connection.	URL, port, internet, DNS, firewall
Socket Connect Failed	The TCP connection could not be opened.	Port, routing, firewall, server address
DNS Error	The hostname could not be converted to an IP address.	DNS server, gateway, hostname spelling
Authorization Failed	The worker or mining account information was not accepted.	Account name, worker format, spaces
Connection Refused	The destination rejected the connection on the selected port.	Correct port, firewall, server selection
Network Unreachable	The miner has no valid network route to the server.	Gateway, IP address, router, internet access
Connection Timed Out	The connection received no response before the timeout.	Packet loss, routing, ISP filtering, port
Connection Reset	An existing connection was unexpectedly closed.	Internet stability, router, firmware, proxy
No Shares	The miner is connected but not submitting accepted work.	Hashboards, worker, algorithm, firmware
Stratum Disconnected	The active stratum session was interrupted.	Network stability, pool switching, miner logs

Pool Dead

Pool Dead is one of the most common ASIC miner connection errors.

It generally means that the miner could not connect to the configured server or that an existing connection was lost.

Possible causes include:

• Incorrect Pool URL
• Incorrect port
• Internet disconnection
• DNS failure
• Firewall or ISP filtering
• Unstable network routing
• Miner firmware problems

Recommended actions:

1. Verify the complete stratum address.
2. Confirm that the selected port is supported.
3. Test another port on the same PECPool hostname.
4. Test another official PECPool regional server.
5. Review the miner's network and system logs.

Socket Connect Failed

Socket Connect Failed normally means the miner could not open a TCP connection to the configured hostname and port.

Possible causes include:

• The selected port is blocked.
• The hostname is incorrect.
• The miner has no internet access.
• The gateway is incorrect.
• A firewall is blocking the connection.
• The ISP is filtering mining traffic.

Test the selected hostname and port from a computer connected to the same network.

Windows PowerShell example:

Test-NetConnection btc-eu.pecpool.com -Port 3333

Look for:

TcpTestSucceeded : True

Linux example:

nc -vz btc-eu.pecpool.com 3333

DNS Error

A DNS error means the miner cannot convert the PECPool hostname into the IP address required for the network connection.

Possible causes include:

• Incorrect hostname spelling
• Invalid DNS server
• Router DNS problems
• Local or ISP DNS filtering
• Incorrect miner gateway
• Temporary internet failure

From Windows Command Prompt:

nslookup btc-eu.pecpool.com

From Windows PowerShell:

Resolve-DnsName btc-eu.pecpool.com

From Linux:

getent hosts btc-eu.pecpool.com

A successful test should normally return at least one IP address.

Do not permanently replace the PECPool hostname with the returned IP address. Server IP addresses may change, while the official hostname continues resolving to the correct destination.

Authorization Failed

Authorization Failed means the miner reached the PECPool server, but the submitted mining account or worker information was not accepted correctly.

The recommended worker format is:

AccountName.WorkerName

Example:

myaccount.miner01

Common mistakes include:

• Entering only the worker suffix
• Using the wrong mining account
• Forgetting the dot separator
• Adding spaces
• Using an email address
• Using a Bitcoin wallet address
• Using unsupported characters

Incorrect:

miner01
myaccountminer01
myaccount. miner01
user@example.com
bc1qexampleaddress

Correct:

myaccount.miner01

Check the Pool Password

The Pool Password field is not your PECPool control panel password.

When no special stratum password is required, use:

x

Never enter:

• Your PECPool login password
• Your email password
• Your Two-Factor Authentication code
• Your API Secret
• Your Bitcoin private key
• Your wallet seed phrase

Connection Refused

Connection Refused means that the network destination was reached, but the selected connection was rejected.

Possible causes include:

• An incorrect port
• A blocked port
• An incorrect server address
• A firewall rule
• A temporary network or service condition

Confirm the exact PECPool hostname and try another supported port.

Example:

stratum+tcp://btc-eu.pecpool.com:3333

If port 3333 cannot be reached, test:

stratum+tcp://btc-eu.pecpool.com:443

or:

stratum+tcp://btc-eu.pecpool.com:25

Using Port 443 Does Not Automatically Mean Encryption

Port 443 is available as an alternative stratum port on PECPool servers.

However, the following address still uses normal Stratum TCP:

stratum+tcp://btc-eu.pecpool.com:443

The port number alone does not change the protocol into HTTPS or an encrypted stratum connection.

Network Unreachable

Network Unreachable means the miner cannot find a valid route to the PECPool server.

Check:

• The miner has a valid local IP address.
• The subnet mask is correct.
• The default gateway is correct.
• The router has internet access.
• The Ethernet cable is connected.
• The switch port is active.
• No VLAN or routing rule blocks the miner.

Example network configuration:

Miner IP: 192.168.1.100
Subnet Mask: 255.255.255.0
Gateway: 192.168.1.1
DNS: Valid reachable DNS server

Connection Timed Out

A timeout occurs when the miner attempts to connect but does not receive a response within the expected period.

Possible causes include:

• Packet loss
• High network latency
• ISP filtering
• Incorrect routing
• Blocked port
• Unstable router or firewall
• A distant or unreliable route

Test another official PECPool region or port and compare long-term connection stability.

Connection Reset

Connection Reset means that an established TCP connection was unexpectedly closed.

Possible causes include:

• Internet interruptions
• Router session problems
• Firewall timeouts
• Mining proxy instability
• Miner firmware problems
• Frequent network route changes

If the error repeatedly affects many miners at the same time, investigate shared network infrastructure.

If only one miner is affected, check that miner's Ethernet cable, switch port, firmware, network settings, and logs.

No Shares

No Shares means the miner may be connected to the pool, but PECPool is not receiving accepted mining work from it.

Possible causes include:

• The miner recently connected and has not yet submitted a share.
• The miner is using the wrong worker configuration.
• The miner is designed for another algorithm.
• The hashboards are not operating.
• Local hashrate is zero.
• The firmware is submitting invalid work.
• Shares are being rejected.

Check:

• Local hashrate
• Hashboard detection
• Accepted and rejected share counters
• Miner algorithm
• Worker configuration
• Miner logs

Confirm the Miner Uses SHA-256

PECPool Bitcoin mining requires a Bitcoin SHA-256 ASIC miner.

A miner designed for another algorithm cannot mine Bitcoin by changing only its Pool URL.

Confirm that the exact miner model supports Bitcoin SHA-256 mining.

Stratum Disconnected

A Stratum Disconnected message means that the active mining connection ended unexpectedly.

An occasional reconnection may occur during a short internet interruption or pool failover. Repeated disconnections should be investigated.

Check:

• Packet loss
• Router logs
• ISP stability
• Miner firmware
• Mining proxy status
• Pool switching frequency

Configure Pool 1, Pool 2, and Pool 3

Most ASIC miners support three pool entries.

PECPool recommends configuring all three addresses so the miner can switch to a backup route when the primary connection becomes temporarily unavailable.

Example for Europe

Pool 1

URL: stratum+tcp://btc-eu.pecpool.com:3333
Worker: myaccount.miner01
Password: x

Pool 2

URL: stratum+tcp://btc.pecpool.com:443
Worker: myaccount.miner01
Password: x

Pool 3

URL: stratum+tcp://btc-us.pecpool.com:25
Worker: myaccount.miner01
Password: x

Example for Iran

Pool 1

URL: stratum+tcp://btc.pecpool.cc:8443
Worker: myaccount.miner01
Password: x

Pool 2

URL: stratum+tcp://btc-as.pecpool.com:443
Worker: myaccount.miner01
Password: x

Pool 3

URL: stratum+tcp://btc-eu.pecpool.com:3333
Worker: myaccount.miner01
Password: x

Use the same mining account and worker name in all three pool entries of the same physical miner.

Why Different Backup Regions Are Useful

Using three ports on one hostname can help when only a specific port is blocked.

Using different PECPool hostnames and regions provides greater routing diversity.

Less diversified:

Pool 1: btc-eu.pecpool.com:3333
Pool 2: btc-eu.pecpool.com:443
Pool 3: btc-eu.pecpool.com:25

More diversified:

Pool 1: btc-eu.pecpool.com:3333
Pool 2: btc.pecpool.com:443
Pool 3: btc-us.pecpool.com:25

Test Ping Carefully

Ping can provide basic information about network latency and packet loss.

Windows:

ping btc-eu.pecpool.com

Linux:

ping -c 20 btc-eu.pecpool.com

However, a failed Ping does not always mean the stratum server is unavailable. Some servers or network devices may ignore Ping while still accepting TCP mining connections.

The TCP port test and accepted-share activity are more important than Ping alone.

Check for Packet Loss

Packet loss can cause timeouts, connection resets, stale shares, and repeated pool disconnections.

Possible signs include:

• Intermittent Ping timeouts
• Large latency variations
• Frequent Pool Dead messages
• Repeated switching to backup pools
• Gaps in the PECPool hashrate chart
• High stale-share rate

Inspect:

• Ethernet cables
• Network switch ports
• Router or gateway performance
• Wireless bridges
• ISP connectivity
• Mining proxy capacity

Check Firewall and Security Rules

A firewall may allow normal web browsing while blocking mining connections.

Check:

• Router firewall rules
• Hosting-provider restrictions
• Corporate network policies
• Outbound port restrictions
• VLAN access rules
• DNS filtering
• ISP port filtering

The miner must be allowed to create an outbound TCP connection to the selected PECPool hostname and port.

Check the Miner Network Settings

Incorrect static network settings can prevent internet access.

Check:

• IP address
• Subnet mask
• Default gateway
• Primary DNS server
• Secondary DNS server

If DHCP is used, confirm that the router has provided a valid address, gateway, and DNS configuration.

Check for Duplicate IP Addresses

Two devices using the same local IP address can cause intermittent access and pool connection failures.

Possible signs include:

• The miner interface opens and closes unexpectedly.
• Ping replies are inconsistent.
• The pool connection repeatedly resets.
• The miner disappears from the router client list.

Review the router DHCP list and confirm that every miner uses a unique IP address.

Check the Ethernet Connection

A miner may remain powered on even when its Ethernet connection is unstable.

Check:

• The Ethernet cable is fully inserted.
• The miner network-port lights are active.
• The switch port shows a valid link.
• The cable is not damaged.
• A different cable and switch port have been tested.

Check Miner Firmware

Firmware controls stratum communication, pool authentication, network behavior, and share submission.

Firmware problems may cause:

• Frequent disconnections
• Socket errors
• Authorization errors
• Duplicate or invalid shares
• Unexpected restarts

Recommended practices:

• Use trusted firmware.
• Confirm compatibility with the exact miner model.
• Review release notes before upgrading.
• Back up the current configuration.
• Do not interrupt power during installation.

Check the Miner Log

The system or kernel log often provides the most useful information about a failed connection.

Look for messages containing:

• Pool Dead
• Socket Connect Failed
• DNS Lookup Failed
• Authorization Failed
• Connection Refused
• Network Unreachable
• Connection Timed Out
• Connection Reset
• Stratum Disconnected
• No Shares

Record the exact error rather than reporting only that the miner is Offline.

Check Mining Proxy Performance

If miners connect through a mining proxy, the connection failure may occur between:

• The miner and the proxy
• The proxy and PECPool

Check:

• Proxy CPU usage
• Memory usage
• Network capacity
• Worker connection count
• Proxy logs
• The proxy's active PECPool connection

When practical, temporarily connect one miner directly to PECPool. If the direct connection works, investigate the proxy or its network path.

Only One Miner Cannot Connect

If other miners on the same network are connected normally, focus on the affected miner.

Check:

• Its Pool URL
• Its worker name
• Its Ethernet cable
• Its switch port
• Its network settings
• Its firmware
• Its miner logs

All Miners Cannot Connect

If many miners lose connection at approximately the same time, investigate shared infrastructure.

Check:

• The farm internet connection
• The main router or gateway
• DNS services
• Network switches
• Firewall changes
• ISP routing
• The mining proxy
• The shared PECPool server configuration

Pool 1 Is Dead but Pool 2 Works

This indicates that the miner and internet connection are generally operational, but the Pool 1 hostname, port, or route has a problem.

Check:

• The Pool 1 spelling
• The Pool 1 port
• Regional routing
• Firewall rules
• Packet loss

If Pool 2 consistently performs better, move that stable address to Pool 1 after sufficient testing.

Pool Is Connected but the Worker Is Still Offline

A connected pool does not always mean that PECPool is receiving valid shares.

Check:

• The accepted-share counter is increasing.
• The worker name is correct.
• The miner has local hashrate.
• All hashboards are detected.
• Shares are not being rejected.

After valid shares begin arriving, allow approximately 10 to 20 minutes for the worker to appear or fully update in the PECPool panel.

Example 1: Incorrect Pool URL

Incorrect configuration:

Pool URL: https://cp.pecpool.com
Worker: myaccount.miner01
Password: x

Correct configuration:

Pool URL: stratum+tcp://btc-eu.pecpool.com:3333
Worker: myaccount.miner01
Password: x

Example 2: DNS Failure

The miner log displays:

DNS Lookup Failed

Recommended checks:

1. Confirm the PECPool hostname spelling.
2. Check the miner gateway.
3. Check the DNS server.
4. Test the hostname from another device on the same network.
5. Restart the router or DNS service when required.

Example 3: Blocked Port

The miner uses:

stratum+tcp://btc-eu.pecpool.com:3333

The hostname resolves correctly, but the TCP test fails.

Test:

stratum+tcp://btc-eu.pecpool.com:443

If port 443 works and accepted shares begin increasing, the original port or network route was being blocked or filtered.

Example 4: Authorization Failure

Incorrect worker:

miner01

Correct worker:

myaccount.miner01

After correcting the worker, save the configuration and confirm that accepted shares begin increasing.

Example 5: Incorrect Gateway

The miner has:

IP Address: 192.168.1.100
Subnet Mask: 255.255.255.0
Gateway: 192.168.2.1

The gateway is outside the miner's local subnet and may not be reachable.

A correct gateway may be:

Gateway: 192.168.1.1

Use the gateway assigned by the network administrator or router.

Recommended Troubleshooting Order

1. Open the miner's status page.
2. Check the active Pool URL.
3. Confirm the PECPool hostname and port.
4. Confirm the mining account and worker format.
5. Confirm that the Pool Password is x.
6. Review the pool status and accepted shares.
7. Review the exact error in the miner log.
8. Check the miner IP address, gateway, and DNS.
9. Test DNS resolution.
10. Test the configured TCP port.
11. Check cables, switches, routers, and firewall rules.
12. Try another official PECPool port.
13. Try another official PECPool region.
14. Review miner firmware and proxy operation.
15. Wait for valid shares and the worker-status update.

Do Not Change Everything at Once

Changing the Pool URL, network configuration, DNS, firmware, worker name, and router settings simultaneously can make troubleshooting more difficult.

Use a controlled process:

1. Record the current error.
2. Change one setting.
3. Save and allow the miner to reconnect.
4. Review the pool status and logs.
5. Confirm whether accepted shares begin increasing.

Common Mistakes

• Using the PECPool website address as the Pool URL
• Forgetting stratum+tcp://
• Using an unsupported port
• Entering an email address as the worker
• Entering a wallet address as the worker
• Using the PECPool login password as the Pool Password
• Configuring only one pool address
• Relying only on Ping
• Ignoring the miner log
• Replacing official hostnames with fixed IP addresses
• Assuming every connection error is caused by PECPool

Quick Checklist

• The Pool URL begins with stratum+tcp://.
• The PECPool hostname is official and spelled correctly.
• The selected port is supported.
• The worker uses AccountName.WorkerName format.
• The Pool Password is x.
• The miner has a valid IP address.
• The subnet mask and gateway are correct.
• DNS resolves the PECPool hostname.
• The selected TCP port is reachable.
• The Ethernet cable and switch port are stable.
• The firewall allows outbound mining connections.
• Pool 1, Pool 2, and Pool 3 are configured.
• The miner log has been reviewed.
• Accepted shares are increasing.
• The worker has been given enough time to update.

When to Contact PECPool Support

Contact PECPool Support when:

• Multiple independent networks cannot reach an official PECPool server.
• Authorization repeatedly fails with a verified mining account and worker.
• The miner submits accepted shares but the worker does not update after sufficient time.
• The same technical error continues after completing all troubleshooting steps.

Provide:

• The mining account name
• The complete worker name
• The miner model
• The configured Pool URL and port
• The exact error message
• A screenshot of the pool status
• Relevant miner log lines
• The approximate time the problem started

Never provide:

• Your PECPool login password
• Your email password
• Your Two-Factor Authentication code
• Your API Secret
• Your Bitcoin private key
• Your wallet seed phrase

Use Official Support Channels

Use only official PECPool support channels:

• The Support section in the PECPool panel
• Official PECPool community channels
• support@pecmine.com

Fix the Connection in the Correct Order

Most pool connection failures can be identified by checking four areas:

1. Pool URL and port
2. Mining account and worker name
3. Miner network configuration
4. The exact error in the miner log

After correcting the issue, confirm that the active pool shows a connected status and that accepted shares begin increasing.

A miner is not fully connected only because it is powered on. Successful PECPool mining requires a stable stratum connection, correct worker authorization, and continuous valid share submission.