Accessing the Virtual KVM on a DRAC5-Equipped Dell Server with IE7
I’ve talked before about Dell’s remote access card, DRAC5 in a previous post. Although a great tool, sometimes just accessing certain features is a pain. Surprisingly, current DRAC5 cards don’t have very good support for IE7 or Firefox, which comprise the lion’s share of browsers out there.
Although I haven’t found a good fix for Firefox browsers, there are some settings that can be configured to allow IE7 to properly install the IP KVM and Virtual Media pluginss of the DRAC5 card.
Here are the steps needed to fix IE7:
1. From the “Tools” menu, select “Internet Options
2. Go to the “Security” tab and highlight “Intenet” and select “Custom Level”
3. Scroll to “ActiveX control and plug-ins”, and set the sub-setting “Automatic prompting for ActiveX controls” to “Enable”
4. Click “OK” a couple of times to save settings and then try to access the DRAC5 KVM plugin again - it should properly install now.
If you don’t have the above settings, when you try to install the DRAC5 IP KVM activex plugin, IE7 will boot you back to the DRAC5 login page. It will continue to do that until the above settings are in place. Why Dell has not updated the plugins yet is beyond me, but with the above settings, you can get around the problem.
How to Configure a Cisco Switch for Network Sniffing
Sometimes it’s necessary to analyze (sniff) packets flowing thru a network for reasons such as congestion or virus outbreaks. I can remember two specific occasions where I had to sniff:
1. A user had fired up a p2p tool and was downloading some music files
2. A user had set an OpenGL screensaver on a Citrix terminal running over a MPLS wan link
In both cases, I used a tool called Wirehark (aka Ethereal) to sniff packets running across the local network which helped me to track down the source of these issues. However, since most networks these days are switched, simply firing up wireshark isn’t enough. The nature of a switched network means that it’s impossible to capture all packets without some special switch configuration, hence the need for port mirroring. Essentially, you tell the Cisco switch to mirror all data across a physical port or range of ports to a destination port. This destination port is special and does not act like a regular port so it is important to document this change. Here’s how it’s done*…
To mirror ports 1-47 to port 48 (assumes you are already on the switch as a privileged user):
conf t
no monitor session (clears out any already there)
monitor session 1 source int fa0/1-47
monitor session 1 destination int fa0/48
end
This configuration will mirror ALL data in/out of ports 1-47 over to port 48. It would be best to do this config on a core switch so that all switches cascaded off the main switch will also be monitored. Crack your laptop into port 48 and launch Wireshark and watch the packets fly!
Once I’ve captured a good chunk of data, I’ll use the conversations feature of wireshark to check out the chattiest machines on the network. Usually with this method I can pinpoint the cause of network congestion and other abnormalities.
*Certain versions of Cisco IOS require different commands, but I have had pretty good luck with the above settings
Disable Windows Update Reboot Nag
Windows Update is a great tool for keeping your computer up to date. However, some updates require a reboot and will keep nagging every 10 minutes to reboot your system. This can be quite annoying, but with a new system policy setting, you can tell the Windows Update interface to not bug you for a real long time, or not at all.
To get rid of the Windows Update Reboot Nag:
1. Go to Start -> Run, then type in gpedit.msc and hit Enter
2. Navigate the Policy Editor interface to: Local Computer Policy / Computer Configuration / Administrative Templates / Windows Components / Windows Update, then double click on “Re-prompt for restart with scheduled installations”
3. You can configure how often it will nag you (I re-configured it for 720 minutes, which means I’ll be asked twice on a work day), or completely disable it.
Internet Explorer Connection Limit
I prefer Firefox for most browsing these days but occasionally I still need to use IE. Unfortunately, there is a hidden setting in IE that limits the number of simultaneous connections per website to 2! That means if you need to download more than a few items from a particular site, you will have to wait until each one is done before you can download the next. Fortunately this setting can be changed from within the Windows Registry.
To update this setting, follow these instructions (use caution when editing registry values):
1. Start Registry Editor (Regedt.exe)
2. Locate the following key in the registry:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
3. On the Edit menu, point to New click DWORD Value, and then add the following registry values:
Value name: MaxConnectionsPer1_0Server
Value data: 10
Base: Decimal
Value Name: MaxConnectionsPerServer
Value data: 10
Base: Decimal
4. Quit Registry Editor
You may need to restart your computer for the settings to take effect, but usually restarting IE will be enough.
Forcing a Remote Citrix Server to Use a Local Host Cache File
At a previous employer, we used Citrix Metaframe Servers at four different sites, with one of the sites handling the central configuration of the Citrix Server Farm. This worked great for the most part, but during extended MPLS WAN (Wide Area Network) outages, the remote servers started to hang up, as they could not “phone home” to get the central configuration datastore.
Forcing the remote servers to temporarily look only at their local configuration cache would result in much better performance. Once the MPLS WAN was back up, I would need to revert to the standard settings.
Part I: Use local cache on when the central datastore is unavailable
1. Stop IMA Service on affected remote server
2. Update registry entries:
HKLM\Software\Citrix\IMA\DatabaseDriver = IMAAccess.dll
HKLM\Software\Citrix\IMA\DataSourceName = M:\Program Files\Citrix\Independent Management Architecture\Imalhc.dsn
3. Start IMA service
Part II: Use central datastore for configuration (once WAN is back online):
1. Stop IMA Service on remote server
2. Update registry entries:
HKLM\Software\Citrix\IMA\DatabaseDriver = IMASql.dll
HKLM\Software\Citrix\IMA\DataSourceName = M:\Program Files\Citrix\Independent Management Architecture\MF20sql2k.dsn
3. Start IMA service
Tech Notes!
I was cleaning up Outlook recently in an effort to be more organized when I realized that I have accumulated a lot of personal technotes over the years, and I decided it would be a good idea to publish some of the more useful topics.
I’ll start by posting a new article tomorrow (time willing), and I’ll continue to try and post a couple of notes every week until I’m all out. Topics will range from Windows XP to Cisco to Windows Server to RedHat / Debian Linux. t’s a pretty wide range of topics, but it’s all stuff that I felt was worth noting at one time or another over the past several years. Hopefully someone else can get some use out of this stuff as well.