2012/01/28

M, A and O flags of Router Advertizement

For some time, it has been quite confusing to me about auto config (SLAAC) in IPv6. Windows 7 can support SLAAC but no DNS resolvers can be allocated. Mac OSX Lion and Linux can support SLAAC + RDNSS which assign IPv6 address and resolvers to client hosts via Router Advertisement. In case there is a DHCPv6 and RA Server in a network segment, things will be complicated to understand. How does a host choose whether to use SLAAC or DHCPv6 or both ? Hopefully, I came across some good description in Cricket Liu’s new book “DNS and Bind on IPv6”. In fact, the A, M, and O flags in RA message have something to do with resolvers.

The “M” flag - for “Managed Address Configuration,” tells hosts that DHCPv6 is available for both address assignment and network parameters (including resolver configuration).

The “A” flag - , for “Autonomous Address Configuration,” tells hosts that SLAAC is available for address assignment and network parameters (possibly including resolver configuration).

The “O” flag - for “Other Stateful Configuration,” tells hosts that DHCPv6 is available for network parameters other than address assignment (that is, to be used together with SLAAC in the hybrid method described earlier).

I still think that Microsoft should release patches to Windows 7 such that Windows 7 can support SLAAC + RDNSS. Think it this way, if there needs a DHCPv6 for resolvers assignment working side by side with RA Server, what is the purpose of developing auto config in IPv6.

2012/01/22

Migration to Office 2007


We have Office 2003 upgraded to Office 2007. No big surprise at all except some more features in the tool bar.  There is one thing in Words 2007 which I think is most useful.  We can now save files in PDF format and this facilitates posting documents to the Internet.  I don’t thank Microsoft at all.  File saving in PDF should be a standard feature and Microsoft just offers the basic minimum to users.


2012/01/18

World IPv6 Launch - 6 June 2012

After waiting for one year, I am happy to see the four biggest content providers in the world, namely, Google, Yahoo, Facebook and Microsoft Bing will enable IPv6 on a permanent basis.  The date of this activation is 6 June 2012 at the World IPv6 Launch event (www.worldipv6launch.org).  After 6 June, I can access facebook by just www.facebook.com instead of www.v6.facebook.com.  I have gogoClient and Hurricane Electric tunnels at home with over 5 Mbps speed for IPv6 connection.  I am sure my IPv6 connection can give me faster speed in surfing Facebook and Google than my IPv4 connection.

One question I have in mind:  Will Google include Youtube for the permanent IPv6 provision ?  If so, that is another great news.  I can have better experience in watching Youtube videos as I can imagine the v6 pipeline of Youtube is not so congested.