What's the best way to store a set of IPv6 addresses?

Question

I'm modernizing a legacy application that stores IPv4 addresses in a fixed-size array of unsigned longs. The addresses are stored in host byte order. That is, it is ntohl()'d when coming from the socket API and htonl()'d when going to the socket API.

Now in order to support IPv6 as well, I'm wondering what to do with this array. Whether I should store the string representation, and make it an array of char[INET6_ADDRSTRLEN] or even a std::vector<std::string> or std::set<std::string> to support more addresses.

Or, I could store the in6_addr structs, which is probably way more efficient to work with than a std::string, but then I'm wondering how does network and host byte order apply here?

Visit: http://stackoverflow.com/questions/26531531/efficient-way-to-store-ipv4-ipv6-addresses — Gaurav Dave, Jan 07 '15 at 11:51
`in6_addr` should be definitely the better choice vs `std::string`. "how does network and host byte order apply here?", well you cannot longer use simple `long` values to store IPv6 addresses. — πάντα ῥεῖ, Jan 07 '15 at 11:52
so just use struct in6_addr and don't try to convert it into a 128bit integer. Seems fair. — Philipp, Jan 07 '15 at 11:56
@Philipp Yes. You should provide a class for encapsulation of the API functions, as I recommended in the asnwer to the linked question above. — πάντα ῥεῖ, Jan 07 '15 at 12:04

score 0 · Answer 1 · answered May 15 '15 at 00:17

0

in6_addr does require the address to be in network byte order. in6_addr internally stores ipv6 address as a union of 16 chars, 8 shorts, 4 ints.

answered May 15 '15 at 00:17

Uday Kiran Katuri

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2

What's the best way to store a set of IPv6 addresses?

1 Answers1