![]() A DNS server (authoritative nameserver or just resolver) using only IPv4 can answer IPv6 AAAA-record queries, and a DNS server using only IPv6 can answer IPv4 A-record queries. intronetworks : both A and AAAA recordsĭNS itself can run over either IPv4 or IPv6.Within the cs.luc.edu DNS zone are defined the following: This book is, as of April 2015, available via IPv6. The DNS requests are sent to the client’s pre-configured DNS-resolver address (probably set via DHCP). The Internet Draft draft-vavrusa-dnsop-aaaa-for-free proposes that, whenever a DNS server delivers an IPv4 A record, it also includes the corresponding AAAA record, much as IPv4 CNAME records are sent with piggybacked corresponding A records ( 7.8.1 nslookup (and dig)). A dual-stack machine usually requests both. ![]() ![]() The IPv6 equivalent is the “AAAA” record, for “Address four times longer”. The DNS system on the client then contacts its DNS resolver and asks for the appropriate address record corresponding to the server name.įor IPv4 addresses, DNS maintains so-called “A” records, for “Address”. In the C language, address lookup is done with getaddrinfo() or (the now-deprecated) gethostbyname(). The first step is the DNS lookup, triggered by the application’s call to the appropriate address-lookup library procedure in the Java stalk example of 11.1.3.3 The Client we use InetAddress.getByName(). But what if the remote site also supports both IPv4 and IPv6? If IPv6 coexists on a client machine with IPv4, in a so-called dual-stack configuration, which is used? If the client wants to connect using TCP to an IPv4-only website (or to some other network service), there is no choice. In this section we will assume that IPv6 connectivity exists at a site if it does not, see 8.13 IPv6 Connectivity via Tunneling.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |