Archives for category: ip addressing

When it comes to ULA, IPv6 gurus get nervous. Some hear NAT, and NAT is the most disgusting word in IPv6 vocabulary.

Well, ULA is not to be NAT-ed (look for Ivan’s ipSpace posts about ULA for more know-how), it can be used in a much smarter way – it can provide an internal connectivity in case when a site gets isolated from its basic networking services like DHCPv6, for example. Yes, these things can happen. Read the rest of this entry »

No need to sacrifice a great protocol due to some privacy issues, better improve it!

IPv6 hosts can use IPv6 Stateless Address Autoconfiguration (SLAAC) to label themselves with one or more IPv6 addresses. These are composed of a network prefix advertised by a local router, and some kind of interface identifier. There are many security and privacy implications if such an identifier is globally unique — addresses with embedded hardware address being a perfect example. On the other hand these kind of addresses are stable, allowing for a higher degree of network control and manageability.
Users privacy can be significantly improved if the interface identifier is random and changes frequently. Such mechanisms, like Privacy Extensions for SLAAC (RFC 4941), can bring a nightmare to many network administrators.

DHCPv6 to the rescue!
Read the rest of this entry »

IPv6 comes with 128-bit addressing. The huge number of all theoretically possible IPv6 addresses is something human beings can not imagine.

The unthinkable number 2128, which is the number of all possible combinations of 128 bits that form an IPv6 address, is so huge that we can not scope with. For example, a precise answer to a question “How many IP addresses are available in IPv6 compared to IPv4” is:

There are 79228162514264337593543950336 times more IP addresses in v6 compared to v4.

You, as myself, might find that information pretty much useless. Let us find some down-to-earth comparisons.