A detailed guide to the latest Ethereum Network Upgrade — Istanbul, and its activation on the Ethereum test networks.What is a network upgrade / hard fork?
A network upgrade is a change to the Ethereum protocol, adding new rules to improve the system. These rules come in the form of Ethereum Improvement Proposals (EIPs) that define in technical terms the changes and features that should be implemented in a network upgrade.
Network upgrades can be planned or unplanned. Upgrades are also known as forks, and normally add features requested by users and developers of the protocol. Unplanned forks have also occurred in order to fix problems with the blockchain or to stop attacks. To date, there have been 7 hard forks on Ethereum. The phrase ‘hard fork’ denotes a network update which is not fully backwards compatible, and has the potential to render some previous transactions invalid, and/or change the existing functionality of deployed contracts.
The decentralized nature of blockchain systems makes a network upgrade more difficult. Network upgrades in a blockchain require cooperation and communication with the community, as well as with the developers of the various Ethereum clients in order for the transition to go smoothly.
In order for upgrades on the main Ethereum network to happen seamlessly, these upgrades are first done on test Ethereum networks, such as Rinkeby, Ropsten, Goerli and Kovan.What is Istanbul?
Istanbul is the 8th Ethereum network upgrade. Previous network upgrades have been given other names such as Spurious Dragon and Byzantium. The current one/last upgrade is Constantinople.
While a specific activation block has not been scheduled for the Ethereum mainnet, blocks have been set for all major test networks.What happens during a network upgrade?
After the community comes to an agreement about which changes should be included in the upgrade, changes to the protocol are programmed into the var...