Archive for April, 2014

EMC Protection Features – 1 picture says it all

April 30th, 2014 Comments off

I found this image on the Internet. This is the best way to explain EMC Protection Features to clients


Categories: Uncategorized

Java Application Error – Security Exception

April 28th, 2014 Comments off

I just updated Java to version 7 update 55 and I can’t login to EMC Navisphere anymore. Java V7u55 just decided to stop the local Java apps without even telling you why. I googled it, most website says you have to add the URL to the “Exception Site List” in the Security tab, but guess what, there is no “Exception Site List” any more.


So you will have to do it the “Old school” way, edit file “exception.sites” and add in the URL at


Note that AppData directory is hidden.


Categories: Data Center, Windows

Cisco Nexus VPC Domain ID

April 4th, 2014 Comments off

For the last 3 days, I’ve tried to configure vPC for a pair of Nexus 5548UP. No matter what I did, the pair just refused to connect and form vPC properly. So far I have tried:
- Upgrading to NX-OS version 6
- Upgrading to NX-OS version 7
- Restarting to factory default configs
- Restarting the switches many times
- Checking cables and connectors

The configurations I had for them were
1 diagram

Shared Config:

First switch

Second switch

And I kept getting this
2 vlan down

3 vpc bri

Do you see the problem? It turned out that’s because I used the same vPC Domain ID as my KeepAlive Port-Channel ID :101. A mistake that can be made easily in my effort of keeping the code clean.

I fixed it by changing everything I could about the configuration, eventually I changed the vPC domain ID and it works

Then I found this Cisco document:
vPC Domain ID Modification on an Active vPC Domain

The vPC peer devices use the vPC domain ID that you configure in order to automatically assign a unique vPC system MAC address. Each vPC domain has a unique MAC address that is used as a unique identifier for the specific vPC-related operations. However, the devices use the vPC system MAC addresses only for link-scope operations, such as LACP. Therefore, Cisco recommends that you create each vPC domain within the contiguous Layer 2 network with a unique domain ID.

Categories: Data Center, Networking