IPV4 LITERAL URL IP IN HOST https://10.1.2.3/ URL PARSER HOST 10.1.2.3 IP CHECK PRIVATE REJECTED THE LITERAL IS RECOGNISED AND FILTERED BRACKETED IPV6 LITERAL URL IP IN HOST [::ffff:0a01:0203] URL PARSER HOST [::ffff:0a01:0203] IP CHECK NOT AN IP? SKIPPED BRACKETS KEPT, NO DNS, REQUEST REACHES 10.1.2.3