Re: [bitcoin-dev] how to disable segwit in my build?

[Dan Libby <dan@osc.co.cr>]

On 07/12/2017 06:48 PM, Anthony Towns via bitcoin-dev wrote:

> I think that terminology isn't quite precise. I think your options are:
> 
>  - if you're a miner or run a mining pool, you can *signal* (or not
>    signal) support for segwit activation; you do this by controlling
>    the block version

I wish to NOT signal for segwit if mining.

>  - if you're running a node, you can choose to *enforce* (or not
>    enforce) the additional consensus rules associated with segwit

I wish to NOT enforce segwit consensus rules.

> 
> I think it's the latter you're talking about. "Activation" is different:
> it's the collective action of the bitcoin ecosystem to start enforcing
> the segwit consensus rules after a sufficient majority of miners are
> signalling support. That's not something you as an individual can control.

good point, thanks for clarifying.

> If you want to disable enforcement of segwit rules, even if a majority of
> mining power signal activation, you can change the code and recompile to
> do so, for example by changing the nTimeout setting for DEPLOYMENT_SEGWIT
> from 1510704000 (Nov 15 2017) to 1493596800 (May 1 2017, already expired).
> This is probably a bad idea, in that it will cause you to risk accepting
> blocks that nobody else in the network will accept, opening you up
> to higher risk of double spends, and may cause you to be unable to
> peer with segwit enabled nodes after segwit is activated if your node
> is rejecting blocks with witness data because you think segwit is not
> enabled while they think it is enabled. To avoid that you would also need
> to stop setting the NODE_WITNESS p2p bit, which you might be able to do
> by setting the nTimeout above to 0 instead of just a date in the past? I
> believe a timeout of 0 gets treated as automatically FAILED. There might
> be other complexities too though.

I've set the nTimeout to 0 already.  I will look into the NODE_WITNESS
p2p bit.

I think that logically, if coded correctly, my node would have no more
risks than any other legacy (pre-segwit) node on the network...

> 
>> I'm not looking for reasons NOT to do it, only HOW to do it without
>> unwanted side-effects.
> 
> The unwanted side-effects are precisely the reasons not to do it. If you
> don't understand what they are, you won't be able to avoid them. :)

fair enough.  But these are the same risks as running any pre-segwit
node, correct?    For example bitcoin-core 0.13.0, or any version of
btcd to date...


-- 
Dan Libby

Open Source Consulting S.A.
Santa Ana, Costa Rica
http://osc.co.cr
phone: 011 506 2204 7018
Fax: 011 506 2223 7359