Gas Limit Cap

EIP-3756, titled "Gas Limit Cap," proposes setting an in-protocol cap for the gas limit of 30,000,000. The motivation behind this proposal is that a high gas limit increases pressure on the network. In a benign case, it accelerates the growth of the state and history faster than can be sustained. In a malicious case, it amplifies the damage of certain denial-of-service attacks. The proposal specifies that as of the fork block N, blocks with a gas_limit greater than 30,000,000 should be considered invalid. The rationale behind capping the gas limit is that the gas limit is currently under the control of block proposers, who have the ability to increase the gas limit to any value they desire. This allows them to bypass the EIP and All Core Devs processes in protocol decisions that may negatively affect the security and/or decentralization of the network. However, the proposal maintains the ability of proposers to lower the gas limit below 30,000,000, as a valuable property of proposers choosing the gas limit is their ability to scale it down quickly if the network becomes unstable or is undergoing certain types of attacks. The document mentions that there are no known backward compatibility issues or security considerations associated with this proposal.