ipv6 masternode support

[vertoe]

Would it be possible to allow ipv6 masternodes?

As discussed here https://darkcointalk.org/threads/for-those-running-several-nodes-whats-your-approach-for-static-ip-addresses.1347/#post-11353

[schinzelh]

Theoretically the code should be IPv6 capable if Evan did not make assumptions on IPv4. Will give it a try on a IPv6 connected machine.

[thelazier]

Many Masternode on IPv6 are online and get payment currently, This issue should be no longer an issue.