One of the talks I did manage to see at TechEd this year was the one about how they managed the network infrastructure for the conference. Part of the presentation when into a bit of detail about how they went about providing IPv6 connectivity including arranging the backhaul from the convention centre back to the Internet.
The things I remember coming away from the presentation were that:
- The need for IPv6 is growing as IPv4 address space dries up
- There’s not much existing hardware or infrastructure that supports it
- It isn’t easy to get working
- Security (Firewalls) becomes a bigger issue when you aren’t using NAT anymore
The hardware is certainly an issue, so it’s good to see that the manufacturers are starting to release entry-level devices that support IPv6. Internode announced today that they’re now selling the NetComm NB6Plus4 which supports IPv4 and IPv6 in “dual-stack mode”. Billion also have their 7800NL router which operates similarly.
I didn’t knowingly use the IPv6 network at TechEd but the comments from those who did were that it was also surprising how few websites were available – even Microsoft Update didn’t work.
A lot of problems still to be solved - interesting times ahead!
Unusually busy on the Excel helpdesk today – Jane’s follow-up question was [how to do the same thing]/2010/09/conditional-text-in-excel-when-cell-has.html) with a range of cells. eg.
My initial suggestion was to use COUNTIF(range, criteria) where the criteria is “*”, but it turns out there’s a better answer – COUNTA(range) which counts the number of cells in the range with are non-empty. So the formula becomes:
=IF(COUNTA(B3:C3), "Y", "N")
If you wanted to do the inverse and only return “Y” if all values in the range are blank, then COUNTBLANK(range) will do the job. Also check out KB 274537 for details on some scenarios when COUNTBLANK doesn’t work so well.
This might seem trivial to us ‘developer’ types, but it was today’s “Jane’s Excel question”.
You have one or more cells in a spread sheet. You want to display some text “Y” or “N” depending on whether the cell has anything in it. eg.
One solution is to use this formula:
=IF(LEN(B3)>0, "Y", "N")
This checks the length of the text in the cell. An empty cell will have a length of zero. Anything greater than zero means the cell has something in it.