How to use VLC Media player to stream multicast video

March 22nd, 2016 Comments off

When testing networks and routing, it is sometimes useful to be able to send a number of multicast streams across the network. VLC media player can do this, but getting it working is not as trivial as I expected. Here’s how to do it:

  1. In the Media menu, choose “Stream”
  2. In the Open Media dialog file tab, click “add” and choose the file you want to stream  and click “Open”
  3. At the bottom, click the “Stream” button
  4. This opens the “Stream Output” dialog showing the source file you have chosen. Click Next to set destination.
  5. In “Destinations”, choose “RTP /MPEG Transport Stream” and click the “Add” button
  6. In the “Address” box, enter the required multicast address (eg and set the port (or leave default at 5004)
  7. In transcoding options, choose the appropriate settings for your video and PC’s codecs. I chose “Video H.264 + MP3 (MP4)”. I had to set the options by clicking the options (screwdriver and spanner) button immediately to the right of the dropdown. In encapsulation, I chose MPEG-TS. In video codec, I set the bitrate to 4000kb/s
  8. Once the options are set, click “Save”. Then click Next for “Option Setup” and select “Stream all elementary streams” then click stream.

To view the stream, open another instance of VLC media player (try it on the same PC before trying it over the network)

  1. Choose Media/Open Network Stream
  2. In address, enter rtp://@ – choose the correct address and port you entered when setting up the stream. Don’t forget to enter the “@” symbol after “rtp://” and before the multicast ip address!
  3. Click “Play”

If you want to stream multiple videos, remember to choose an different multicast address and/or port

Categories: Networking

Setup MPIO for EMC VNX Storage

April 23rd, 2015 Comments off

If you use EMC PowerPath, the process is straightforward from EMC. But in most cases, due to the price of EMC PowerPath, we use Microsoft MPIO instead (Which PowerPath uses under the covers)

If using Microsoft’s MPIO, you can use their mpclaim utility from a command line or their GUI for doing all the setup. The following assumes you are using Microsoft MPIO and an EMC VNX storage array. There are only slight variations for other combinations.

  1. Configure hardware for MPIO.
  2. Install Microsoft MPIO.
  3. From a command prompt, issue the command “mpclaim -h” to see the currect storage devices claimed by MS MPIO. With a VNX you should see something like “Vendor 8Product 16″. Looking at the MPIO Devices tab in the GUI will show the same information.
  4. From a command prompt, issue the command “mpclaim -s -d” and you should see that there are no disk present yet, as you haven’t allowed any.
  5. From a command prompt, issue the command “mpclaim -e” to display the vendor product ID string for the connected storage array. Depending on how your VNX is configured, you will see something like this “DGC VRAID”.  There are exactly five (5) spaces after “DGC” and you must have exactly five spaces in the ID.
  6. Now you can add the multipath support for the speicifc IDs you want. Obviously you will want whatever you saw in the previous step, but in case you plan on using some other configurations, you can add everything from the list from above. From a command prompt enter the command “mpclaim -n -i -d “DGC VRAID”. The “-n” switch suppresses the automatic reboot. Repeat that commnd for each all device IDs desired.
  7. Reboot the system.
  8. From a command prompt, issue the command “mpclaim -s -d” and you should see the disks claimed by MPIO on the node. Again, you can use the GUI for all this, too.
  9. Run Disk Management and activate the new disk


Categories: Data Center, Windows

Vsphere snapshot hang – How to (force) kill a VM process

April 16th, 2015 Comments off

I had a frozen VM because the snapshot hang at 95%. I could not do anything to the VM because its process is locked to the host. I couldn’t stop it, couldn’t cancel the task either. To release the lock and force kill it, I had to do the following:
- Restart the management agents
- Force stop the VM
- Consolidate the snapshot (if necessary)
- Restart the VM

1. Restart the management agents
These 2 commands should do

2. Force stop the VM
a. The VMWare way

World ID: 46664
Process ID: 0
VMX Cartel ID: 46640
UUID: 42 24 e8 f3 28 35 e1 77-dd 56 40 46 d2 a4 16 43
Display Name: plsw-ts2012-fe1
Config File: /vmfs/volumes/5156099e-0e41f131c77b4/VM-NAME/VM-NAME.vmx

Then collect the “Word ID” and run either of these commands

At this point the VM should be stopped and the lock is released. You might need to remove and re-add it. If the VM is still lock, we will need to force stop it the Linux way

~ # ps | grep 52173320
52173320 52173320 vmx /bin/vmx
52173323 52173320 vmx-vthread-4:VM-NAME /bin/vmx
52174736 52173320 vmx-vthread-5:VM-NAME /bin/vmx
52174737 52173320 vmx-mks:VM-NAME /bin/vmx
52174738 52173320 vmx-svga:VM-NAME /bin/vmx
52174741 52173320 vmx-vcpu-0:VM-NAME /bin/vmx

The second column is the master process number . Run this command to kill it

KB 1004340 should provide you with some more methods but these 2 are usually good enough

I need a few more PMI-PDU

February 13th, 2015 Comments off

This is the 3rd year of my PMP certificate. I have been collecting PDU by attending meetings, doing volunteer works, practicing PMI and on going training.

I need 7 more PDU to renew my certificate I have 11 months to do it.
Does anyone need a project manager for a volunteer job ?


Categories: Project Management

Cisco WLC: Per-client Packet Capture

February 9th, 2015 Comments off

Sometimes, you just want to capture the packets associated with a particular wireless client and see what the heck is going on with that client. Often, it may not be practical to do an over-the-air packet capture, as perhaps the client is at a remote location or just just don’t have access to a wireless capture card.

I recently had an issue trying to understand why an Android device that I was trying to ‘on-board’ using Cisco’s ISE wouldn’t access the Google Play store. I desperately wanted to capture the over-the-air frames from the client to have a look at what the client was doing.

After a quick ‘Google’ around, I found an intriguing set of Cisco WLC CLI commands that allow a packet capture of traffic for a wireless client. This can all be done without having to change the AP mode, or reboot the AP etc.

In summary, the feature allows packets to be captured for a specified wireless client that is sending/receiving traffic to/from an AP. The AP will continue to process all user traffic as per usual, with the target client frames being streamed to an FTP server for a specified period. The resultant capture file is in standard pcap format that can be opened with Wireshark (amongst others).

1. Identify the client MAC address you would like to capture
2. Identify the FTP server to receive the trace file:
config ap packet-dump ftp serverip path username password

3. Configure the frames to be captured – data frames worked well for me:
config ap packet-dump classifier data enable

4. Start the client packet capture for the target client:
config ap packet-dump start

5 After a while, you can stop the capture sessions and see what you’ve got: (note that by default, the capture session stops after 10 mins)
config ap packet-dump stop

(The FTP server may not show any frames captured until you stop the capture and it empties out its buffer)

There are a few caveats to this capture technique, but it is still a very powerful tool to add to your WiFi utility belt. Caveats include:

  • Beacons and probe responses are not captured
  • The client must be associated with an AP joined to the WLC
  • Only frames for one client at a time can be captured
  • Does not work from inter-controller roaming
  • More info is here

    Categories: Wireless

    Packet capture with Nexus 1000V

    January 20th, 2015 Comments off

    Today I thought I’d take a look at creating a SPAN session on the 1000v to monitor traffic. I found it really easy to do! SPAN is one of those things that takes you longer to read and understand than to actually configure. I find that true with a lot of Cisco products: Fabric Path, OTV, LISP, etc.

    SPAN is “Switched Port Analyzer”. Its basically port monitoring. You capture the traffic going from one port and then mirror it on another. This is one of the benefits you get out of the box for the 1000v that enables the network administrator not to have this big black box of VMs.

    First I need to see which vethernet is assigned to which VM. This command can help you do that


    Then create a monitor session with the following commands

    And confirm the monitor session with the command


    In this case, we have an error. The state is “Down”. That is because VMTEST1 and VMTEST2 are in 2 difference VM Hosts. After moving them to the same host, the state will change to up

    Intra-VLAN multicast traffic on Nexus 7000

    November 11th, 2014 Comments off

    I have couples of 3750 and Nexus 5K connected to 2 Nexus 7010. The N7Ks run in VPC mode. I have a Multicast source and multiple multicast receivers, they are on the same VLAN. This VLAN is only a Layer 2 VLAN.

    The issue is, only the receivers that are on the same access switch with the source receive the traffic. If the receivers are on difference access switch, they don’t see the IGMP Join Group packet.

    A bit of digging around, I found out the reason, is that the other switches does not have an mrouter port and does not know about the source.

    There are 3 solutions to fix the issue:
    1. Turn on an SVI interface and enable PIM
    3. Turn off IGMP snooping on ALL switches.

    Let’s focus on solution #2. Since I don’t need to route the multicast traffic outside of the VLAN, this is the best solution:

    To do this on the Nexus 7000 you need to do the following:

    Where x.x.x.x is an un-used IP address
    And you need to run these command on both VPC switches

    For more information, have a look at this article

    Categories: Data Center, Networking