Bitcoin Core will typically hook up with no less than 10 outbound friends (8 common, 2 blocks-only). It can ask all the friends for his or her chaintips after which begin synchronizing the header chain for the chaintip with essentially the most work after selecting a single header sync peer. Solely when it has acquired all block headers of the peer and validated them to the extent potential, will it begin downloading blocks and advancing its lively chaintip. So long as considered one of our node’s friends is sincere and caught up, we’d already be on our method to the precise chaintip.
A block whose timestamp is older than the median of the 11 previous blocks would merely be rejected on the header sync stage, so we should assume that the attacker is serving a blockchain that may be a week previous.
If our node had been eclipsed and all of its friends had been providing solely a chaintip that’s older than per week, our node would synchronize that chaintip. Our node would stay in “initialblockdownload” state, as that solely disables as soon as the timestamp of the node’s lively tip is not more than 24 hours up to now. This may e.g. trigger the pockets GUI to show a warning that the node is just not caught up. The node would additionally begin making further connections resulting from not making progress. If it finds any sincere peer, it can proceed synchronizing in direction of the precise greatest chain. If the eclipse assault persists, it can stall, however stay in IBD.
