London Mainnet Announcement | Ethereum Foundation Blog

Important Update

On July 21, 2021, a consensus difficulty was recognized on the Ropsten community, the place the go-ethereum, Erigon and Nethermind implementations had totally different transaction validation logic than Besu and OpenEthereum. New variations of the affected shoppers have been launched and are linked within the “Client Versions” desk under. The block quantity for London is unchanged, and nonetheless is 12 965 000. Node operators utilizing an affected consumer MUST improve to the newest model.

An overview of the problem is offered within the “Ropsten Consensus Issue” part.


After a profitable testnet deployement, the London improve is now able to be activated on the Ethereum mainnet. It will go dwell on block 12 965 000, which is anticipated between August 3-5, 2021.

Client Versions

In order to be appropriate with the London improve, node operators might want to replace the consumer model that they run. The variations, listed under for every consumer, help London on the Ethereum mainnet. These releases are totally different from the beforehand introduced releases that supported London on testnets. Previous variations don’t help London on mainnet.

Client Version Number Download Link
go-ethereum (geth) 1.10.5 1.10.6 Download
Nethermind 1.10.77 1.10.79 Download
Erigon (f.okay.a. TurboGeth) 2021.07.03-alpha 2021.07.04-alpha Download
Besu 21.7.1 21.7.2 Download
OpenEthereum (f.okay.a. Parity) v3.3.0-rc.4 Download
EthereumJS VM v5.5.0 Download


  • For miners: London will change how the goal gasoline restrict is dealt with on the community. Please see the “As a miner, what do I need to do?” part under for particulars.
  • The Besu model was up to date on August 4, 2021. This was as a result of a non-London associated bug affecting the transaction pool. See extra right here.
  • The go-ethereum, Nethermind and Erigon variations have been up to date on July 23, 2021. This was as a result of Ropsten consensus difficulty, detailled under.
  • The OpenEthereum consumer can be deprecated after the London improve. The OE group is working with Erigon on a clean transition path for customers. More data will be discovered right here.

London EIPs

The following EIPs are included within the London improve:

The Ethereum Cat Herders have put out a weblog submit going over the main points of those EIPs.

It is value noting that EIP-1559, whereas backwards appropriate with the present transaction format, introduces modifications to the block header, provides a brand new transaction kind, comes with new JSON RPC endpoints, and modifications the habits of shoppers in a number of areas (mining, transaction pool, and many others.). It is very beneficial that tasks familiarize themselves with the EIP. A extra in depth checklist of assets associated to EIP-1559 will be discovered right here.

Bug Bounty Bonus

In order to get extra eyes on the modifications coming within the London improve, all bounties for vulnerabilites associated to London improve can be doubled, up till the improve occurs. Examples of points that will be eligible for a doubly are cross-client consensus points between the next shoppers: Geth, Besu, Nethermind, OpenEthereum and Erigon. For full particulars in regards to the bug bounty’s scope and restrictions, see

Ropsten Consensus Issue

On July 21, 2021, a consensus difficulty was discovered on the Ropsten testnet. The difficulty was attributable to a missed validation for 1559-style transactions by some consumer implementations. In brief, a transaction whose account’s steadiness was bigger than the efficient gasoline utilized by the transaction, however decrease than the transaction’s maxFeePerGas multiplied by the gasPrice was included in a block erroneously.

A full postmortem of the problem is on the market within the eth1.0-specs repository. The affected variations containing this bug are go-ethereum 1.10.5, Nethermind 1.10.77 and Erigon 2021.07.03-alpha. If you’re operating certainly one of these variations, please replace your consumer to the model listed within the desk above.


As an Ethereum consumer or Ether holder, is there something I have to do?

If you employ an alternate (reminiscent of Coinbase, Kraken, or Binance), an online pockets service (reminiscent of Metamask, MyCrypto, or MyEtherWallet), a cellular pockets service (reminiscent of Coinbase Wallet,, or Trust Wallet), or a {hardware} pockets (reminiscent of Ledger, Trezor, or KeepKey) you don’t want to do something until you’re knowledgeable to take extra steps by your alternate or pockets service. If you run your individual Ethereum node, it’s essential improve your node. See the “As a non-mining node operator, what do I need to do?” part under.

As a non-mining node operator, what do I have to do?

Download the newest model of your Ethereum consumer, as listed within the desk above.

As a miner, what do I have to do?

First, obtain the newest model of your Ethereum consumer, as listed within the desk above. Then, you will have to manually change your gasoline restrict goal to twice what it at the moment is. This is as a result of as soon as London is dwell, the block dimension can be doubled and EIP-1559 will maintain blocks about 50% full. This will be achieved through JSON-RPC, with out restarting your node, on all shoppers which supply mainnet-compatible mining.

For instance, if previous to London you have been a targetting a block dimension of 15,000,000 gasoline, you’ll now want to focus on a 30,000,000 gasoline restrict to keep up the identical quantity of transactions per block, on common. If you don’t change your gasoline restrict goal on or after block 12 965 000, you’ll begin decreasing the block dimension on the community . The desk under offers the precise API name for every consumer it is best to use to replace your gasoline restrict goal.

Note: Nethermind, Erigon and EthereumJS don’t but help mining on the Ethereum mainnet.

What occurs if I’m a miner or node operator and I don’t take part within the improve?

If you’re utilizing an Ethereum consumer that isn’t up to date to the newest model (listed above), your consumer will sync to the pre-fork blockchain as soon as the improve happens. You can be caught on an incompatible chain following the outdated guidelines and you can be unable to ship Ether or function on the post-upgrade Ethereum community.

What is a community improve in Ethereum-land?

A community improve is a change to the underlying Ethereum protocol, creating new guidelines to enhance the system. The decentralized nature of blockchain techniques makes a community improve tougher. Network upgrades in a blockchain require cooperation and communication with the group, in addition to with the builders of the assorted Ethereum shoppers to ensure that the transition to go easily.

What occurs throughout a community improve?

After the group involves an settlement regarding which modifications ought to be included within the improve, modifications to the protocol are written into the assorted Ethereum shoppers, reminiscent of geth, Erigon, Besu and Nethermind. The protocol modifications are activated at a selected block quantity. Any nodes that haven’t been upgraded to the brand new ruleset can be deserted on the outdated chain the place the earlier guidelines live on.

Why “London”?

After Istanbul, we ran out of names for our deliberate community upgrades. It was steered to make use of Devcon metropolis names for upgrades, and we did! London is the place Devcon 1 happened. It adopted the Berlin Devcon 0.

Thank You!

A giant because of everybody who has been concerned in researching, planning, implementing, testing, breaking, fixing, re-testing, deploying, stress-testing and helping in some other method getting London deployed ???

Shout out to Benjamin Davies for the quilt picture for this submit!


This is an emergent and evolving extremely technical house. If you select to implement the suggestions on this submit and proceed to take part, it is best to ensure you perceive the way it impacts you. You ought to perceive that there are dangers concerned together with however not restricted to dangers like surprising bugs. By selecting to implement these suggestions, you alone assume the dangers of the results. This submit and proposals are usually not a sale of any variety, and don’t create any warranties of any variety together with however not restricted to something associated to the Ethereum community, or the Ethereum shoppers referred to herein.

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