## networking na freenode resolveu o problema.
Veja link
Ambos os macbooks tinham hamachi vpn instalado por coincidência.
This is the hamachi interface. When Hamachi started their service, they chose the 5.0.0.0/8 network as their pool of addresses to avoid conflicting with any existing ranges. However, hamachi were never allocated this range.
In the past couple of months, RIPE (who are responsible for this range) have started selling blocks in the 5/8 network. This was inevitable with the quickly depleting numbers of ipv4 addresses, yet hamachi are still using this block.
Nossos servidores ips estão nessa faixa.
Em um sidenote, todos os envolvidos em encontrar o problema estão achando isso hilário.