Blog du Tristank : Tales from the Road

ISA Server 2006 TCP Retransmits

tristank — Wed, 14 Oct 2009 04:24:20 GMT

Health Checks

I perform ISA Server Health Checks for Premier Support (via Premier Field Engineering) as part of my role.

I’ve seen something a few times recently that I thought it might be helpful to call out, while poking around in the Performance Monitor TCPv4 counter area.

The Problem

In short: Lots of TCP retransmissions per second.

Like, lots. More than 1% is annoying; any more than 5% and you pretty surely have a problem.

Recently, I’ve been seeing 20%.

That’s right, kids, according to Perfmon’s statistics, one in five TCP packets requires retransmission.

If your ISA Server seems like it might be a bit slow, and you haven’t looked yet, go look. I’ll wait. You’re interested in the TCPv4 object, specifically the Segments/sec and Segments Retransmitted/sec counters.

What I’ve seen looks like this:

The green area is TCPv4\Segments/sec. The red area is TCPv4\Segments Retransmitted/sec. They’re using the same scale.

Notice that the retransmission figures track with the overall volume.

This 20% figure has been seen across Intel and Broadcom server NICs, so I don’t think it’s specific to either vendor.

Fixing It

In at least one of the places I found this, a simple driver upgrade to the latest version available looked like it fixed the problem.

Otherwise, it could indicate a NIC issue, or a hardware issue with the switch.

If you find yourself in this situation, and do resolve it, please do post details in the comments section below.

My new roadmouse

tristank — Wed, 07 Oct 2009 02:43:41 GMT

They wanted me to post about Windows phones.

Well, I’m going to fight the power. Buck the trend. Talk about my new favourite travelling companion.

It is the surprisingly-catchily-titled Microsoft Mobile Memory Mouse 8000.

First cool feature: Magnets everywhere!

The wireless transceiver doubles as a 1GB USB stick, and has a magnetic doohickie on the end that the charge cable happily snuggles up to.

The same cable has another magnetic dock on the underside of the mouse.

Next cool feature: Use it like a wired one!

With the mouse power switch in the “off” position, I’m still happily mousing away with the cable connected.

Next cool almost-hidden feature: It does Bluetooth too!

You can select between the 2.4Ghz Wireless thingy supplied by the dongle, or regular Bluetooth connectivity with a switch under the battery cover. And since I got bluetooth fixed on my laptop, that actually makes some sense, and means that – as long as it’s charged already – I can use the mouse for a fair while without having to find the memory stick slash dongle slash cord thing.

I have no idea how I came into possession of this one, but it’s quickly replaced the (fleet of) Notebook Optical Mouse (s) that I’ve loved – yes, loved - over the years for its size, lightness and plucky go-anywhere courage.

It is, however, heavier: there’s a nice metal finish, and obviously a rechargeable battery in there, but I don’t find myself minding that much.

From the wish-it-didn’t department: 4-way scroll wheel that I’d have happily substituted for a fatter non-side-scrolling regular wheel (middle clicks are a bit sharp and rolly), and thumb buttons discreetly out of thumb’s reach on the left. I hate thumb buttons (unlike Jeff), but these are unobtrusive enough that you’re unlikely to hit them accidentally.

So perhaps I’m just getting old – and I certainly don’t play as many first person shooters as I used to, especially not on this 1.2Ghz-and-PATA-toting Dell XT – but this mouse seems to do just fine for the moment. Recommended!

Brought to you by the number 8000, and the word “shill”. :)

PL15W2SP.DLL vs Firewall Client

tristank — Wed, 19 Aug 2009 14:37:00 GMT

As I possibly misspelled or misremembered it, the PL15ws2p.dll (possible sic) file was installed as a Winsock Layered Service Provider on a couple of boxes at a customer site.

Coincidentally, these machines were Windows Server 2008 machines where we couldn’t get the Firewall Client to work properly.

We found that there was a third party LSP using:

NETSH WINSOCK SH CA > catalog.txt

And then opening catalog.txt in notepad. The properties of the Pl15ws2p.dll indicated that it was a signed DLL from American Power Corporation or similar (APC or ACP; one of those no-notes half-hours), and that it was used in some sort of management capacity.

But only one of the machines had this APC software installed on it, and the other didn’t… perhaps it got left behind when it was being uninstalled? The search engines didn’t seem to know much about it.

Either way, next step was clear:

NETSH WINSOCK RESET

To return the Windows Sockets provider list to its shiny defaults, and reboot the computer.

After that, the Firewall Client wasn’t working (which we expected).

A Repair from Not-Called-Add-Remove-Programs-Any-More-Now-It’s-Programs-And-Features-Silly fixed that up.

Cool, huh? Remember: when nothing makes sense and the configuration looks good, perhaps LSPs are to blame?

Now if only I could get my stupid Huawei 3G modem working on my Win7 laptop again (“Device attached to the system is not functioning”… thaaanks).

Vista-Stylez File Management in Windows 7 Beta

tristank — Sun, 18 Jan 2009 16:07:24 GMT

If you’re finding file management frustrating because the folder pane seems strangely inactive in the Windows 7 beta, it’s probably because it is. It’s perfect for light filing use, but not so good for folder-stuffing and navigational acrobatics. Which I seem to do.

I filed a bug using Send Feedback on that just now, complaining it was harder to organize files en masse with the new system, especially with an extensive folder hierarchy, cos I had to use two windows, and while I love the Snap Left and Snap Right feature to a point, blah, blah blah, whine. (Hey, does anyone know how to tile vertically?)

Of course, seconds after filing the bug, I experimentally right-clicked in the folder area of the Win7 Explorer interface, and there are precisely the options to restore Vista-like behaviour:

It’s also in Folder Options. (oops). The trick to finding it in the Explorer pane is to right-click a blank area, not one of the items.

My bad. Sorry, Win7 team. I take it all back, and I’ll pay for any damage*.

Home Hyper-V Networking Gotchas

tristank — Tue, 13 Jan 2009 15:12:56 GMT

Before the holidays, I bought myself an early present: a new quad-core box with 4GB RAM, which I was going to use for a home Hyper-V lab, so that I could run a bunch of 64-bit VMs as well as the 32-bit staples I’ve been using for years (SBS 2003, and a separate ISA Server box).

I’d had Windows Server 2008 installed on my Virtual Server host for a while, and use it with Routing and Remote Access (RRAS)’ NAT to provide a simple internet gateway for a segment of my internal network.

Lesson #1: Core Quad Q8200s don’t support VT (that’s Hyper-V, kids)

There was a 1300Mhz FSB Q8200 available for the same price as a Q6600, and I figured that I couldn’t go wrong with that. Surely, I thought, all Intel CPUs since the Core2 Duos support Hyper-V?

Well, no, said Intel, and thanks for your money (stupidty tax, I seem to pay a lot of it). The one Quad core chip that doesn’t support Hyper-V is the one I bought. Q8200 is being phased out (I read somewhere), so this mistake should be easily avoidable in the future. Or now, by how-you-say smarter people.

Lesson #2: When you Hyper-V-ify a Parent Partition, It’s Sort Of A Client Too (aka “You may need to set stuff like RRAS up again with the new virtualized network adapters”)

What I mean by this is that when I got the Right CPU and installed Hyper-V, I was without Internets.

To cut a long and boring troubleshooting story short: the physical network adapters I’d configured in RRAS were no longer the Right Network Adapters.

I set up new virtual networks for each physical adapter (one Internet, one Local), and then had to set up RRAS again, because it didn’t think there were any new interfaces to set up – it was quite happy only seeing the old ones, thank you very much.

After checking both virtual adapters were visible in the Network Connections interface, and that they had the right IPs assigned, I rechecked my Windows Firewall settings and ran a port probe to confirm only ports I knew I wanted open were open (RRAS Basic Firewall doesn’t exist any more in 2008, so be careful with dual-homing where the Internet is attached to one of your adapters).

The disconnect here was that I was assuming the parent partition would see the physical hardware – it does, it just doesn’t use it directly any more, it looks like it uses the virtualized setup instead, at least to some extent.

Lesson #3: Hyper-V and DHCP didn’t like each other when the physical host became the parent partition

My RRAS server had (to this point) been my DHCP server for the internal network. This was all fine, and seemed to be working okay (or had my lease durations just not expired yet?), except for the new virtual hosts I created today.

There’s some lore floating around on the forums that worked for me – the bit that worked was manually adding a REG_MULTI_SZ called IPAddress to the likeliest-looking adapter interface in the registry, because Hyper-V setup for whatever reason doesn’t do that.

The DHCP server wouldn’t bind to the physical adapters (or even show them in the Bindings interface), presumably because IPv4 and IPv6 was unbound from them (interesting, hey?) and also wouldn’t show me either of the virtual adapters, which I guess is due to the lack of a static IP address on either of them.

Now, though, my setup’s working nicely, everything more or less as it was before, only virtualized. And thus, you know, more sexy.

Back With A Semblance

tristank — Tue, 13 Jan 2009 13:16:15 GMT

It’s a new year, I have a new job, and I have new stories to tell*!

I had a lovely Christmas break, thanks for asking, and now I’m back, I’ve moved into my new role as a Premier Field Engineer. PFEngineering is the part of the organization tasked with helping customers optimize and healthify their deployments of our software.

In my new role, I spend more time on fewer things, and more time actually in customer environments. I’m a professional poker, prodder and proofreader.

My focus has expanded, from IIS alone out to IIS, ISA Server, PKI and Security, and I’m likely to be expanding those a little further too.

It’s good to be back in the field. I enjoy working in real (and, um, virtualized) environments, with real (and virtualized) people, fixing things quickly, demonstrating my suddenly-wonderful touch-enabled Dell XT Tablet PC (Mary Jo might hate touch, but I’ve been sold since I used it with Teh Vistar, and Win7 is even better… more on that some other time).

* I lied about having new stories to tell right now. But soon. Sooooon.