Version bits: Does Classic uses the same flags in the block header as XT?

[Peter R]

Does Classic uses the same bit flags in the block header as XT?

I'm curious because if it does, then the ~500 existing XT nodes technically don't have to upgrade to remain compatible should the 2 MB "Classic" fork get activated.

[Note that Unlimited nodes are already compatible with both XT and Classic.]

 

[TinoDesigns]

Good questions. I'd like to know that as well.

 

[solex]

Agreed. It is important that existing XT non-miners are fine with classic blocks >1MB.

Edit: the proposed changes for Classic show compatibility, also another doubling to 4MB in 2 years.

https://github.com/bitcoinclassic/bitcoinclassic/pull/3/files

FORK_BLOCK_VERSION = 0x20000008

which is the XT version +1

We are also going to need a priority BUIP to synchronise BU with Classic for sigops.

 

[Peter R]

@solex

I'm confused. A non-mining XT node needs to see 750/1000 blocks with the correct version bits before it will accept blocks greater than 1 MB. If the Classic block version is 1+XT version, will 750/1000 such blocks still trigger the XT nodes?

Obviously Gavin and Jonathan would have thought about this, but I could imagine them both wanting to make it compatible, or wanting to require the XT nodes to upgrade.

 

[solex]

@Peter R
You are right, I didn't consider the trigger itself, just the higher block version.
Actually it begs the question of how safe it would be for XT nodes because, if the trigger was met, they would accept blocks >2MB right off, so a miner propagating a 3MB block would have XT nodes accepting it while it was being rejected by Classic.

 

[Peter R]

@solex

Yes, that is the logic why they may have NOT used the same version bits. I ventured over to the Classic Slack forum to ask but didn't get a good answer. Don't feel like digging through the code myself...

Personally, I think ideally the fork should activate the XT nodes too. No one is going to mine a 3 MB block and even if they did, it would just get orphaned 10 minutes or so later--no different than the few orphans that occur each day anyways.

 

[AdrianX]

I was told on r/bitcoixt that it does. So XT nodes don't need to fork if it's implemented.

Obviously it's subject to change.


Who knows what classic will be lots of attacking going on.

Hell even LukeJr is in there trying to get Classic to change the mining algorithm so it forks off Bitcoin.

 

[allegro101]

According to the Bitcoin Classic repository the Bitcoin Classic block version number will be pushed to 0x20000008 in hex and 536870920 in decimal. (This is one higher than BIP101's version number, which was 0x20000007)
https://github.com/bitcoinclassic/bitcoinclassic/pull/3/files

 

[TinoDesigns]

any updates on a realease of classic?