nanog mailing list archives
Re: using ULA for 'hidden' v6 devices?
From: "Jima" <nanog () jima tk>
Date: Thu, 26 Jan 2012 07:39:58 -0700 (MST)
On 2012-01-26, Owen DeLong wrote:
If you can't point to some specific advantage of ULA over secondary non-routed GUA prefixes, then, ULA doesn't have a reason to live.
My biggest concern with secondary non-routed GUA would be source address selection. If you're trying to talk to something in 2000::/3, it's obvious to the OS that it should be using its address in 2000::/3 rather than the one in fc00::/7. When both the "external" and "internal" addresses live in 2000::/3, more care has to be taken to ensure the system DTRT.
I'm not sure where DNS64/NAT64 comes into play here for v6 to v6 communication. For IPv4, I don't see any advantage in ULA+NAT64 vs. the more reliable and easier RFC-1918 with NAT44 possibilities, even if you have to run multiple RFC-1918 domains to get enough addresses, that will generally be less complicated and break fewer things than a NAT64 implementation.
My best guess there is the ability to a) only manage a single-stack network (I really wish more software supported IPv6 so this could be a more feasible reality), and b) use the same NAT64 prefix across various NAT64 instances (64:ff9b::/96 is a blocker if you actually want to allow NAT64 to RFC1918 space). While I can see the potential appeal of the second point, I'm not sure I'd agree with it myself. Jima
Current thread:
- using ULA for 'hidden' v6 devices? Justin M. Streiner (Jan 25)
- Re: using ULA for 'hidden' v6 devices? Cameron Byrne (Jan 25)
- Re: using ULA for 'hidden' v6 devices? Jay Ford (Jan 25)
- Re: using ULA for 'hidden' v6 devices? Dale W. Carder (Jan 25)
- Re: using ULA for 'hidden' v6 devices? Nick Hilliard (Jan 25)
- Re: using ULA for 'hidden' v6 devices? Dave Pooser (Jan 25)
- Re: using ULA for 'hidden' v6 devices? Justin M. Streiner (Jan 25)
- Re: using ULA for 'hidden' v6 devices? Owen DeLong (Jan 25)
- RE: using ULA for 'hidden' v6 devices? George Bonser (Jan 26)
- Re: using ULA for 'hidden' v6 devices? Owen DeLong (Jan 26)
- Re: using ULA for 'hidden' v6 devices? Jima (Jan 26)
- Re: using ULA for 'hidden' v6 devices? Owen DeLong (Jan 26)
- Re: using ULA for 'hidden' v6 devices? Cameron Byrne (Jan 26)
- Re: using ULA for 'hidden' v6 devices? Nick Hilliard (Jan 25)
- Re: using ULA for 'hidden' v6 devices? Cameron Byrne (Jan 26)
- Re: using ULA for 'hidden' v6 devices? Owen DeLong (Jan 26)
- Re: using ULA for 'hidden' v6 devices? Cameron Byrne (Jan 26)
- Re: using ULA for 'hidden' v6 devices? Douglas Otis (Jan 26)
- RE: using ULA for 'hidden' v6 devices? George Bonser (Jan 26)
- Re: using ULA for 'hidden' v6 devices? Chuck Anderson (Jan 26)
- Re: using ULA for 'hidden' v6 devices? Mark Andrews (Jan 26)