Re: [bitcoin-dev] BIP Status updates (including to Active/Final Status) - BIP 39, BIP 43, BIP 44, BIP 67, BIP 111, BIP 125, BIP 130

[Jonas Schnelli <dev@jonasschnelli.ch>]

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>> Additionally, BIP 111 (NODE_BLOOM service bit) has been implemented in Bitcoin
>> Core and derivatives; it is unclear if used by clients yet. Can developers of
>> such clients please comment and let me know: 1) if their software supports
>> this BIP already; 2) if not, do they intend to support it in the future?
>> If and only if there are any clients using this service bit already, I will
>> update BIP 111 to Final Status in 2 weeks also.
> 
> Multibit is adding detection of the NODE_BLOOM bit in the next 2-3 weeks.
> 
> SPV is kinda broken if the wallet doesn’t do this detection. If your wallet connects only to nodes that don’t support bloom filtering, the wallet never gets updates. We have had a spike in users reporting that their wallet isn't getting updated. To compound the problem, they rescan the blockchain and lose all of their transaction history. It has caused much panic among less technical users.
> 
> We believe that failing to detect the NODE_BLOOM bit is the culprit, although it is non-deterministic, so we aren't certain.
> 
> I imagine that other SPV wallets are having similar issues. BIP 111 really isn’t optional at this point, so it should be marked final.

SPV Wallets should definitively update to respect NODE_BLOOM. Bloom
filtering is CPU and disk intense and some node operators have disabled
it (or will disabled it) because there is no direct p2p network-health
benefit.

SPV wallets should probably also make use of the new DNS seeder filter
option.
It is running at least on seed.bitcoin.sipa.be and
seed.bitcoin.jonasschnelli.ch.

The filter option allows SPV Wallets to only get nodes that signal
support for NODE_BLOOM.

The syntax is

   x<networkservice_flags_filter_as_int>.seed.bitcoin....

Example for NODE_NETWORK together with NODE_BLOOM
dig x5.seed.bitcoin.jonasschnelli.ch
(NETWORK = (1 << 0), NODE_BLOOM = (1 << 2)) = (bin00000101 = (int)5)


</jonas>


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