the whois command in c6 references whois.v6nic.net for ip addresses in the 43.0.0.0/8 range (and maybe others). v6nic is no longer a valid whois server, any nets delegated to it should instead be delegated to apnic.
i have no upstream connections... this change was made in the generic sources for jwhois some time ago
I see this fix was introduced in F20 here, https://bugzilla.redhat.com/show_bug.cgi?id=1121512