Jumbo Frames Cisco SG-300 20

There is alot of discussion about using Jumbo Frames in a home  environment  and let me come out and say no I do not  recommend it. However; most of us are looking to test it or use it in a lab and that is what I have done.

Cisco SG-300-20
2 PC’s running Windows 8 with Intel 82579V Gigabit

The test: Do jumbo frames provide a  significant  boost in networkspeed and traffic. Please keep in mind that everyones network is different this was tested on a closed loop. I used some software called iperf to transfer data over 10 seconds 3 times. I only recorded the highs and the lows. In times where there was  significant  loss the test allowed for one run to be excluded when run again.

Also these images are for ants. I dont know why they are too small but Im too lazy to fix it.

Test 1 – Check normal transfer rates.

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Result was normal and expected.


Test 2 – Check with all devices configured to accept 4K Frames.
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Result showed 30+ MB gain in transfer rates.

Test 3 – Check what happens when there are 2 hops that have jumbo frames enabled.
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Results showed there was about 10MB loss per hop this is guesstimated that other hops would be the same as I had no other switching devices to add.

Test 4 – Run Jumbo Frames (4K) in an environment where some switching devices will not accept the frame.
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Result showed that there was a significant loss in speed as the data becomes fragmented and resent.

Test 5 – 9K Frames baby!
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This is where it got odd form me. I seemed to have a high loss in speed when I set 9K frames over my devices. I ensured all my hardware supported it however I can not explain why this happened. I will have to look into it later.

Test 6 –  Jumbo Frames mixed MTU enviroment. This basically means that one PC is set to 4K and the other is set to 9K.

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I was  actually  surprised to see that there was not more of a loss but it seemed to work ok.

Test 7 – One sided Jumbo Transfer. In this layout only one PC and the switch have frames enabled.

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Results were about the same as the last test as expected.


Tired of users connecting to AP’s you dont know about? | Blocking specific or all SSID’s Windows 7

This guide was written for Windows 7 but I am going to assume it works for Windows 8 as well.

Problem: My users (or kids) are connecting to SSID’s that they shouldnt be. My users should only ever connect to my work SSID. My users should never be allowed to use AD-HOC SSID’s (Cell phone generated AP’s)



Solution: Quickly block their ability to do this with netsh. Create a GPO when you have time.

What we are going to do first is simply block a single SSID or network with netsh. For this example we are going to use FreeWifiZone as the SSID as this is a common fishing network. Open a command line as administrator and type the following:

netsh wlan add filter permission=block ssid=FreeWifiZone networktype=infrastructure
netsh wlan add filter permission=block ssid=FreeWifiZone networktype=adhoc

These two command will block the SSID in both modes, this will give the desired effect. You will notice a red X over the network now in the  connection list. To verify that this is enabled type:

netsh wlan set blockednetworks display=show

This is good and all but your saying how I cant know all the SSID’s, well no you cant. So you simply block all and explicit allow the one you need. For this example we will use WorkWifi as the good AP we want to keep.

netsh wlan add filter permission=allow ssid=WorkWifi networktype=infrastructure
netsh wlan add filter permission=denyall networktype=infrastructure
netsh wlan add filter permission=denyall networktype=adhoc

Now that your users are right pissed that they cant connect to anyone wifi your going to start to get calls, and when your busy at home you dont want that. So lets just hide the other (blocked) wifi AP’s so that the user  perceives  to see no open wireless at all. And they are not even tempted to try and connect.

netsh wlan set blockednetworks display=hide

There you have it!


OSX 10.8 Slow SMB?

We recently recieved some new giant iMacs in the office and they were neat. Till we realised how slow they were at indexing SMB shares. They seemed tor un really quick but as soon as you opened a network share that was hosted on Windows Server 2003 or 2008 R2 it was unbearable.

Problem: SMB shares are slow on OSX 10.8.

Solution: Add in SMB.conf and nSMB.conf to the /etc/ dir.
Alright this is where I say to you dont do this  unless  you know what your doing I take no responsibility for you bricking you new iMac if you somehow mess up this simple task.

First you need to open a terminal, in this terminal navigate to /etc/ using cd /etc/ .

Now you will need to open a text editor or nano/vi a new file called nsmb.conf 
In that file you will want to add the following lines:


Once you have these added simple save the file. If you dont have permissions then give it first. And reboot. Now you will see all the issue will be fixed!

Notes: There seems to be some confusion on if you need nsmb.conf or smb.conf I made both anyways.

Source: http://www.avenza.com/forum/index.php?topic=742.0 


Adding the DNS-321 to ESXi Datastore

Recently I came into posession of some DNS-321’s and I thought to my self; Hey! Lets use these with ESXi  wouldn’t  that be fun! And yes if you have the network speeds to support it, it is fun.

Issue – I have a D-Link NAS and would like to add it to ESXi as a  data store.
The DNS-321 is a simple device however there are a few tricks we have to apply before we can actually add the device to ESX.

Solution – First we need to ensure that the DNS-321 is up to date.
Dlink has pulled the page required to download the newest firmware (Firmware: 1.03). Luckily I found it on their public FTP (http://www.mmnt.net/db/0/0/ftp.d-link.com/Multimedia/dns321/Firmware ).

Now you need to log into your DNS-321 and upload the firmware file, keep it in the zip. To do this go to Tools and Firmware on the right. Click the Choose File button and find the downloaded firmware it will be called: dns321_fw_103.zip 

Once the firmware is loaded you will see that there are some new options under Advanced / Network Access. Mainly what we are going to be working in is NFS as this is how ESXi will talk to the NAS. Now we will want to add some information to the DNS-321 such as who will connect and what folder will be mounted.

3-11-2013 1-19-57 PMFirst you need to enable the NFS server, Choose the Enabled radio button and hit Apply.
Once the page refreshes choose the Type radio button under Access Settings. You will need to fill in the host field, this is the IP address of your ESXi Server, for this example lets pretend its .


3-11-2013 1-22-20 PMNow we need to tell the DNS-321 what folder we want to mount when the host connects, click browse. You will see a list of volumes open up. Select the volume you want to open by pressing the +.

3-11-2013 1-23-10 PMBy default you might not have any folders on the DNS-321, this will be the case for most people. Simply choose the new folder icon and name your folder.


3-11-2013 1-25-11 PMAfter you have created a folder click it and you will see the name populate into the bottom box. Press OK. It will now take you back to the main Network Access page but most of the values will be filled in.


3-11-2013 1-28-24 PMNow its important that before you hit save settings you set the permissions to R/W: Read/Write.

Now click Save Settings. The page will refresh and you will now see a list of folders and the IP addresses that can be associated with them.
They should look something like this: – Volume_1/VMs | Real path: /mnt/HD_a2/VMs

3-11-2013 1-34-50 PMWe are almost done in this end, we need to add a user to the DNS-321 before we can finish up. This user can exist on ESX, so we cant use root. For this example we will use esxiuser as the username. Simply go to Advanced / ‘Users/Groups’ and add your user.

3-11-2013 2-09-43 PMNow we need to log into vCenter and add the same user that we just added to the DNS-321, same username same password.


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Once you have done that you need to add the datastore. Im going to only upload one image and its bound to look stupid so follow these instructions close. Click your ESX host, then choose the Configuration tab, now under Hardware choose Storage, on the right choose Add Storage…

3-11-2013 1-43-45 PMNow a window ill pop up. Choose NFS Network File System. Then click next and a new window ill appear. Pay attention to the folder names as this is where most users go wrong.


3-11-2013 1-48-42 PMNow we need to fill in the IP of the nas: , and then the folder we want to mount on the NAS, following this example we made a folder called VMs (case sensitive!) /mnt/HD_a2/VMs

3-11-2013 1-52-00 PMGive it a name and your good to go! Press next and your done! You will now see your datastore mounted.

Windows Live Mesh not working anymore? Cant find a good P2P Sync application?

Recently Microsoft sent out a 3-11-2013 8-23-39 AM about a service they offered called Windows Live Mesh (WLM). for those of you who  didn’t  know WLM was amazing it allows you to keep two files in sync over the internet without any fees or paying at all. I mean why not you own the storage and you pay for your internet why  shouldn’t  it be free! Regardless the emails were basically telling us they were closing WLM forever.


What jerks. Now I have to find a way to move 150GB across my WAN everyday. I tried multiple solutions then a buddy told me about AeroFS.

Issue – WLM is shut down and I am not longer able to freely sync data over the internet without going to the cloud. Please note AeroFS is not a cloud syncing app. It is a cloud app that syncs your data from Peer to Peer (P2P) no data is actually stored in the cloud. If you want to store your data in the cloud (P2C) look at Cubby by Log Me In.

Solution – Download AeroFS and set it up. You may be saying WOAH wait a  minute  this isnt a guide. Well its not. AeroFS just works and that is whats so great about it. The system is so easy to set up a 5th grader could do it.

If you want more information on AeroFS check out a  excellent  write up here.

UPDATE: AeroFS is now open to the public.