Bitmain disconnects a mining pool and faces centralization criticism

A new technical inconvenience has emerged in the Bitcoin mining ecosystem, affecting Bitmain S21+ antminer hardware users, one of the most recognized manufacturers in the sector.

According to recent reports on social network X, the latest firmware update of this model It has generated connectivity problems with certain mining pools, including Ocean Pool. This situation has unleashed criticism among the miners, who see in this inconvenience a potential threat to the principles of decentralization that support Bitcoin.

The user Singgekino_Miner, who identifies as an operator of Bitcoin Knots nodes, was responsible for reporting the problem on April 15, 2025. According to his publication, after updating his S21+ Antminer team to the most recent firmware, he lost the ability to connect both to Ocean Pool and the Pool of Brains. Singekino_miner stressed that another identical team, but with an earlier version of the firmware (of February 7, 2025), did not present this inconvenience and can connect without problems.

In his message, the miner expressed his frustration, noting that this restriction, intentional or not, represents a clear violation of the principles of decentralization, since no manufacturer should have the ability to limit user options regarding where to direct their computing power.

Another user, known as Bitcoin Mechanic and who is a representative of Ocean Pool, amplified the complaint by sharing the report of Singero_miner and implied that it is not the first time that Ocean must work on errors that have origin in Bitmain. He also said that Your team is already working to find a solution. However, he recommended to miners to use the S21+ antminer+ refrain from updating to the most recent firmware until the inconvenience is resolved.

To this conversation was added Skot, known in the community for being the main promoter of the Bitaxe, open source devices that allow mining at home with Mini Asics. Skot, in responding to Singgekino_Miner, expressed his disbelief And he suggested that the problem is probably not intentional.

Although criticisms have been overwhelming, it is important to consider this inconvenience It might not be the result of a deliberate decision by Bitmain.

Firmware errors that affect compatibility with certain Pools are not a new problem in the mining industry, and in many cases they have been resolved by subsequent patches and updates. Luke Dashjr, another fundamental member of Pool Ocean, however showed skepticism regarding the manufacturer’s intentions.

In his comment, Dashjr said he is not willing to give Bitmain the “benefit of doubt”, and said the company He has a history of hiding sabotage under the facade of “technical errors”. He referred to a past incident, although without explicitly referring to it, in which Bitmain supposedly kept a functional firmware for months, releasing it only after the community detected and denounced an alleged “ruling.”

This description of the problem fits with the “Antbleed” case, in which a “back door” was discovered (Backdoor) In the firmware of several antminer models (S9, R4, T9, L3, L3+) that allowed Bitmain to turn off the teams remotely and link them to sales and deliveries records, compromising user privacy. According to certain statements, Bitmain applied a patch to Antbleed on April 27, 2017.

For Dashjr, this antecedent suggests that the current problem with the connection to Pools such as Ocean Pool may not be accidental, but part of a deliberate strategy of the manufacturer to influence the mining ecosystem. However, the Antbleed case is not sufficient proof that allows ensuring that the disconnection of the S21 model with Ocean Pool is intentional.

Why does the new Bitmain firmware not allow to connect to Ocean?

Marko Tarman, leading mining manager of Nicehash, participated in the discussion in X, and offered a technical explanation about the origin of the problem.

He suggested that the new s21+ firmware seems to be sending a configuration message before completing authentication with the pool, which causes the connection to close unexpectedly.

This observation suggests that the ruling could be corrected with an adjustment in the way in which the firmware interacts with the pools, and it is possible that Bitmain, by identifying this error, can launch a corrective patch in the next few days or weeksrestoring the complete functionality of the antminer S21+ and allowing users to reconnect with the affected pools.

Until the publication of this article, Bitmain has not officially pronounced on the problem reported by users.

The impact of this problem could be extending beyond individual users. Gru user, another active member of the community in X, commented that this failure could be Related to the recent descent in Ocean Pool hashratea metric that measures the total computing power contributed to a mining pool.

If more miners face problems to connect to Ocean Pool due to Bitmain firmware, this could explain the reduction observed, affecting both the pool operators and the miners who depend on it to obtain their rewards. It is not safe, however, that this is due to the reduction of hashrato in the pool.