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I recently troubleshot an issue where cookie persistency was not working properly when failing over from the active node to the passive node in a Citrix Netscaler HA cluster (high availability cluster). I found the issue was that if the date and time on your appliances are not the same, the cookie will be invalid causing persistency to fail when failing over to the passive node. That’s a big issue because all your users will lose their sessions during a failover.

To quickly check your appliances:

1. SSH using Putty into your NSIPs of your Netscalers.

2. Type “shell” to enter the FreeBSD shell

3. Type “date” to see the current date, time, and time zone. Both your Netscalers should be identical.

4. If they are not identical, set the time by typing the current date and time in the following format:

date yymmddhhmm.ss

For example, to set the date to June 28, 2010 12:13 PM with 15 seconds left in the minute:

date 1006281213.45

You will get this result if you are successful:

Mon Jun 28 12:13:45 CST 2010

5. Now if your timezone says GMT or something instead of your correct time zone, then you need to navigate to timezone file directories by typing:

cd /usr/share/zoneinfo

6. Type this to list all the different zone folders:

ls -l

7. To set the timezone, copy your timezone file to the localtime folder. Below, I am setting the timezone to CST (Central Standard Time):

cp /usr/share/zoneinfo/America/Chicago /etc/localtime

8. Now just type “date” again and it should be the correct time, date, and timezone. That’s it, you’re done! Let me know if you run into any trouble.

On older Netscaler appliances, the command to clear your Netscaler configuration and reset it to factory defaults used to be:

clear config –c y

But on newer devices, the command is:

clear ns config level

where level is one of the following:

1. basic – which clears everything except NSIP, MIPs, SNIPs, network settings, HA, features, and the nsroot account

2. extended – which clears everything except NSIP, MIPs, SNIPs, network settings, & HA

3. full – which clears everything except teh NSIP and default gateway

So typically, I type this to do a full wipe:

clear ns config full

You can also do this through the GUI by going to System > Diagnostics > Maintenance > Clear Configuration. Use the drop down box to select basic, extended, or full then click the Run button.

With that said, I have run across newer devices (even running NS 9.1 and newer) that just don’t clear all their config info. For those, I have just done the following to reset:

1. SSH using Putty into the Netscaler and login
2. Type “shell” to enter shell
3. cd /nsconfig
4. Rename the configuration by typing “mv ns.conf ns.conf.bak”
5. Type reboot

This should reset the device to the IP of 192.168.100.1 with the nsroot/nsroot account credentials. Your licenses and SSL certs will remain though since these are files and not part of the Netscaler config. You will have to delete them manually via WinSCP.

UPDATE 6/29/10: To completely reset your Netscaler to “factory new” conditions, it’s a little bit more work but I have outlined the procedure here:

http://www.jasonsamuel.com/2010/06/29/how-to-really-set-a-netscaler-back-to-factory-defaults-factory-new-condition/

I’m doing some firmware updates on Citrix Netscaler appliances today and thought I would give you guys a quick guide on how to do this. This applies to all legacy appliances, MPX appliances, and VPX appliances. You use the same procedure for both Classic and nCore firmware packages. It is very easy to do.

1. Login to MyCitrix at http://citrix.com/English/mycitrix/index.asp and download the firmware .tgz package. Make sure to check compatability with your appliance before downloading.

2. Use WinSCP to transfer the package to the /var/nsinstall directory on your appliance.

3. SSH into your appliance using Putty and type “shell” to enter the shell

4. Type cd /var/nsinstall

5. Type ls to list the contents of the directory and verify your newly uploaded firmware package is there

6. Now type “tar -zxvf build-xxxxxxxx.tgz” to unzip the package

7. Then type “installns” to begin the install. Should take about 30 seconds to copy to flash and install.

8. Reboot the appliance once prompted for it (just type Y).

9. Login via the web GUI and verify the firmware version in the top right corner is the same as the package you were trying to apply.