The Citrix servers reported that they are too busy to provide access to the selected resource. This message was reported from the XML Service at address [com.citrix.xml.NFuseProtocol.RequestAddress].

Got this issue the other day on my web interface. I was unable to launch any app from any server in my farm. Qfarm / load showed normal load on all servers.

Issue turned out to be a corrupted load evaluator. Switching to default load evaluator fixed the issue. I was then able to recreate my custom load evaluator and reapply it.

Error while creating Central Management Store in Lync 2010

During a Lync 2010 install, in the section for publishing your topology, I got an error while creating my Central Management Store

Error in the logs were:

Error: An error occurred: “Microsoft.Rtc.Common.Data.SqlConnectionException” “A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 – Error Locating Server/Instance Specified)”

After doing a bit of research this is caused by Windows Firewall. Just shut it off and try again and it should work fine.

HA agent has an error : cmd addnode failed for primary node: Internal AAM Error – agent could not start. : Unknown HA error error

Got the error on a vSphere 4.1 host. I have three hosts in the cluster and the other two are working fine. After doing some investigation I edited the \etc\hosts file on the vSphere hosts and found it had the wrong IP address for one of the hosts in the cluster. Fixed that and issued a reconfigure HA command to the host resolved the issue!

“Error 692: Hardware Failure in the Modem” Error Message When You Dial an RAS Server

Part of troubleshooting RAS (PPTP and L2TP) VPN connections is constantly tweaking your settings (both client and server) and reconnecting. This becomes a complete pain when Windows 7 decides its sick of trying and just starts generating a error 692, forcing you to reboot before you can try connecting again.

Finally after endless reboots I found a Microsoft hotfix which addresses this:

Download here:

http://support.microsoft.com/hotfix/KBHotfix.aspx?kbnum=980399&kbln=en-us

Cisco acquires NewScale

Take a look:

http://www.theregister.co.uk/2011/03/29/cisco_buys_newscale/

Cloud computing is really becoming a overused term. Everyone is signing on to it, but most people don’t even really understand it. This will either be the future of IT or a complete fad. I give it 50/50 odds.

Enter to win a free copy of The Accidental Administrator: Cisco ASA Security Appliance

Given my off again, on again love/hate relationships with Cisco ASA’s, I was contacted by Melanie Yarbrough, a community editor here at the IT Knowledge Exchange who figured my readers might be interested in an opportunity to win a copy of  The Accidental Administrator: Cisco ASA Security by Don Crawley.

I am of course a big supporter of pretty much anything that is free but this book does look genuinely interesting and I suggest taking a look!

http://itknowledgeexchange.techtarget.com/itanswers/free-it-book-the-accidental-administrator-cisco-asa-security-appliance/

Proposed Wi-Fi standard to override 3G

http://www.reghardware.com/2011/03/23/wifi_public_hotspots/

An interesting article and raises a point which should be taken a step further. All major cities should have a public and free wifi network. It doesn’t have to be fast but it should be there. Some cities have already been working towards this, particularly in Asia, but in North America I see this as pretty far off which is a shame.

Citrix Health Monitor errors

I was working on a Citrix Presentation server 4.5 server recently and after a blue screen and a reboot users were unable to connect to the server for published apps anymore. Resource manager showed the server had maximum load.

Event viewer show errors on 4 files:

1. RequestTicket.exe
2. CheckTermSrv.exe
3. LogonMonitor.dll
4. IMATest.exe

Event log error was CitrixHealthMon event id 4004

The file C:\Program Files\Citrix\HealthMon\Tests\Citrix\RequestTicket.exe does not have the correct permissions. In SDDL, the expected ACL was O:BAD:AI(A;ID;0x1200a9;;;LS)(A;ID;FA;;;BA). The actual ACL was O:BAD:PAI(A;;FA;;;LS)(A;;FR;;;NS)(A;;FA;;;BA). For reference, the files placed in the test folder should have inheritable permissions turned on which will result in the file have full control access for the Administrators group, Read and Execute access for the Local Service user account, and the owner will be the Administrators group.

I checked the permissions on the file in question and they were completely correct.

However after some searching and experimenting I found a solution

Open a command prompt and navigate to
C:\Program Files\Citrix\HealthMon\Tests

Run these commands

icacls citrix /remove “NT AUTHORITY\LOCAL SERVICE”
icacls citrix /remove “BUILTIN\Administrators”
cacls citrix /G “NT AUTHORITY\LOCAL SERVICE”:R (answer Y to prompt)
cacls citrix /E /G “BUILTIN\Administrators”:F

After this restart the Citrix Health Monitoring and Recovery and check the eventlog. The problem should now be resolved.

IPv6 to create Spam filtering issues

http://www.theregister.co.uk/2011/03/08/ipv6_spam_filtering_headache/

Actually this is just one of many problems. There are many reasons to keep databases of IP addresses and this is going to be somewhere to be painful to impossible to manage.

The dangers of Mirror ports and Etherchannel

I was brought in to troubleshoot an interesting issue with some Cisco switches yesterday. I had a stack of 3750′s(Core) and a stack of 2960S’s. Etherchannel was set up on both sides to connect the two stack’s together. Each time they were connected they would work for about 20-30 minutes and then bring the network down. i immediately suspected Spanning Tree to be at fault but after some investigation with a colleague we found that Spanning tree wasn’t the issue.

In troubleshooting we discovered that when we plugged in the port channel there was immediately a massive amount of data transversing it, far too much to be normal. Doing some digging we discovered there was some mirror port configuration on the switch which was mirroring one port of my Etherchannel to another port on the Etherchannel thus causing a type of traffic loop which eventually completely floods the switch.

Not likely an issue I will see again but a valuable lesson on pruning old configurations after they no longer apply.