RFC1546 anycast and IPv6 anycast

(RFC1546 is mostly conceptual)

Address format
RFC1546 anycast addr is identifyable
IPv6 anycast addr looks like unicast

TCP processing
RFC1546: modify TCP (connection hijack?)
IPv6: no proposals so far

Source address
RFC1546: anycast addr in source address is permitted, not encouraged
IPv6: anycast addr in source address is banned

Both are almost never tested