HOW-TO: Create an Aggregated Link in Solaris

Nowadays, servers ship with multiple network interface cards (NIC). The rationale behind this, is you will use them for high availability implementations or utilize the other NIC as a private lan for backup. If the box is not designed this way, it doesn't usually get deployed in the enterprise.

Previously, we featured a procedure in deploying IPMP or IP Multipathing. Starting with Solaris 10, there is this feature that is much more robust than IPMP. It is called link aggregation; others call it trunking, but they pertain to the same technology. The equivalent in Linux is NIC bonding.

Link aggregation only works on full-duplex, point-to-point links that operate at identical speeds. Make sure that the interfaces in your aggregation conform to this foremost requirement. If you are using a switch in your aggregation topology, make sure that you have configured the ports to be used as an aggregation. Modern switches can support Link Aggregation Control Protocol or LACP. If so, have it configured in either active mode or passive mode.

[1] Assume the Primary Administrator role, or become superuser.

[2] Determine which interfaces are currently installed on your system.

# dladm show-link 
bge0         link: up        speed: 1000  Mbps       duplex: full
bge1         link: up        speed: 1000  Mbps       duplex: full

The command dladm show-dev can also be used here. However, this command will not only show the NIC but also the HBAs (host bus adapters) that are installed on the host. Seasoned veterans know the prefixes of Solaris NIC naming convention so this should not pose an issue.

[3] Determine which interfaces have been plumbed.

# ifconfig -a

[4] Create an aggregation. Syntax is:

# dladm create-aggr -d interface key
interface
  represents the device name of the interface to become part of the aggregation.
key
  the number that identifies the aggregation. The lowest key number is 1. Zeroes are not allowed as keys.
# dladm create-aggr -d bge0 -d bge1 1

The above command is not limited to two (2) NICs. As many NICs can be used as there are physical NICs on the server. Just separate each NIC with -d to join them in the aggregate creation.

[5] Configure and plumb the newly created aggregation.

# ifconfig aggr[key] plumb IP-address up
# ifconfig aggr1 plumb 192.168.0.11 netmask + broadcast + up

[6] Check the status of the aggregation you just created.

# dladm show-aggr
key: 1 (0x0001) policy: L4      address: 0:3:ba:77:84:e (auto)
       device   address           speed         duplex  link    state
       bge0     0:3:ba:77:84:e    1000  Mbps    full    up      attached
       bge1     0:3:ba:77:84:e    1000  Mbps    full    up      attached
# ifconfig aggr1
aggr1: flags=2008843 mtu 1500 index 5
inet 192.168.0.11 netmask ffffff00 broadcast 192.168.0.255
ether 0:3:ba:77:84:e

The above configuration is not yet persistent across reboots. To make it persistent, create a file in this manner: /etc/hostname.aggr[key]. In this example, that translates to /etc/hostname.aggr1.

Add the IP address (192.168.0.11) to the file /etc/hostname.aggr1. Another option is to add the hostname of the server as the content of /etc/hostname.aggr1, but the IP address has to be added to the hosts file. The approach of adding the IP address is simpler and very straight forward.

Do a reboot to test if the aggregation persists across reboots.

Link Aggregation is very picky on both the hardware, driver, speed, duplex and on the switch port. So in most cases where aggregation doesn't work, IPMP is being deployed. To know more about the advantages and disadvantages of each, check out this comparison betweek Link Aggregation vs IPMP.

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HOW-TO: Outlook Hack -- Blank Mail Subject Reminder

How many times have you forgotten to include a subject when you send emails through Outlook? If you ask me, I have done that a lot of times. Including subjects in mails is a good etiquette. It gives the mail a formal setting and bats the message across the recipient even though he/she has not read the mail yet. The subject gives the reader a clue as to what the content is, or whether it is important, or worth reading.

To get a warning when sending an email with a blank subject, just follow the simple steps mentioned below and see the result. Kindly read through the entire procedure first before starting to make modifications with outlook.

Here is the procedure:

[1] Launch Microsoft Outlook.

[2a] Press [Alt]+[F11]. This opens the Visual Basic Editor.
-or-
[2b] Tools > Macro > Visual Basic Editor.

Then View > Project Explorer to open the project menu Project-Project1 on the left side-bar. Or Press [CTRL]+[R] if you prefer doing this through hot-keys. On Microsoft Outlook 2007, the project title is Project1 (VbaProject.OTM)

[3] On the Left Pane, one can see "Microsoft Outlook Objects" or "Project1", expand this. Now one can see the "ThisOutLookSession".

[4a] Double-click on "ThisOutLookSession". It will open up a Code Pane on the right hand side.
-or-
[4a] Right-click on "ThisOutLookSession" and select "Code Pane".

[5] Copy and Paste the following code in the right pane (Code Pane) and Save it:

Private Sub Application_ItemSend(ByVal Item As Object, Cancel As Boolean) 
 Dim strSubject As String 
 strSubject = Item.Subject 
 If Len(Trim(strSubject)) = 0 Then 
  Prompt$ = "Subject is Empty. Are you sure you want to send the Mail?" 
 If MsgBox(Prompt$, vbYesNo + vbQuestion + vbMsgBoxSetForeground, "Check for Subject") = vbNo Then 
  Cancel = True 
  End If 
 End If 
End Sub

At this point you should be seeing a similar window as below. This is a screenshot of Outlook 2007 SP2. You should be seeing a similar window in another version of Microsoft Outlook.

[6] Now whenever you try to send a mail without subject, a pop-up is raised to remind you of the blank subject.

If using Microsoft Outlook 2007, configure security settings so the macro will run via Tools > Macro > Security. Set it to Warnings for all Macros.

The next time Outlook is restarted, select Enable Macros for ThisOutlookSession.

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MODS: Compudesk -- Computer Integrated into a Desk

Let's face it, the downside to desktop computer setups are the cable clutter it brings. Even with a good cable management system things don't change much, once the clean-up schedule comes it's a torture to tidy things up. This is usually the cause of dress downs I get -- the cable clutter of my desktop. It always brings the impression that the necessary clean-up routines and regular upkeep are not performed.

Lately, I came across a very unique idea introduced by a computer enthusiast named Peter Brands, a Dutch computer modding hobbyist. His modding project? A desk that houses his computer system he christened "The L3P DESK". And the end result is a uber unique futuristic modern look that anyone would envy. His idea of the desktop is almost clutter-free and is a really clean look in the real sense of the word.

The descriptions above don't give justice to the set-up, so without further ado.. Pictures of his setup.

But wait there's more.. Without lights, the acrylic and UV reactive parts come to life.

Of all the mods I have seen so far this one takes the cake!

Further details and pictures of his build are here -- build details and build gallery.

(Credits to l3p and tweakers.net)

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TWEAK: Setup Caching DNS Server using TreeWalk

News from around the web recently revolved around security breaches and hacked websites. And when news broke out, many others found out about breaches on their systems too. Beefing up security on their end was too late.

For us end-users, protection is likewise necessary. Examples of everyday threats include viruses and DNS poisoning. However, it is not limited to those. Like the saying goes an ounce of prevention is better than a pound of cure. These attacks may look simple but the impact may be huge -- a big chain reaction. If you have lost data due to a virus before, we don't have to tell you how painful (and expensive) that experience can be.

One good way to overcome DNS poisoning is to setup you own DNS cache that forwards requests straight and direct to root DNS servers or trusted DNS servers. Don't rely on your ISP for DNS services when you can put up your own. It is very easy!

Bind is the actively developed software for this purpose. It is compatible to just about any operating system out there and bind is the same software we will deploy. For Windows, TreeWalk is the trunk that is freely available. Download the application installer directly from the developer or any of the mirrors.

Install it and start the service, there is no need to reboot after install. Open a command prompt as Administrator and start the service with net start twdns. Or use the Management Console (Start > Run.. > services.msc), scroll down to twdns and start the service.

The software installs itself on C:\Windows\System32\dns on 32-bit machines. While on 64-bit ones the path is C:\Windows\SysWOW64\dns. Then just configure the system to use the local DNS server. It is now recommended to turn off Windows very own DNS cache or DNS client. It would make no sense for it running in parallel with bind.

If you followed our recommendation of running your own proxy server on your computer system, stay tuned as we will utilize the DNS cache we just installed with our proxy server.

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TWEAK: Fully Functional DivX HiQ Plugin on Firefox 4/5

A couple of weeks back, we featured DivX HiQ codec on Firefox and Chrome on an article entitled Flash Without Adobe Flash Player, and as promised here is the tweak to make the DivX HiQ plugin compatible to Firefox 4.0.1 and even the later Firefox 5.0.

First, locate the folder C:\Program Files (x86)\DivX\DivX Plus Web Player\firefox (on 64-bit systems) or C:\Program Files\DivX\DivX Plus Web Player\firefox (on 32-bit systems). Under this directory are two folders html5video and wpa. Inside these folders are the web plugins that DivX installed and we need to tweak. There is a text file named install.rdf in each of the directories.

On line 17 of wpa\install.rdf, change the line to:

<em:maxVersion>5.*</em:maxVersion>

Likewise for html5video\install.rdf, do the same for line 12 of that text file:

<em:maxVersion>5.*</em:maxVersion>

Now restart Firefox and check the add-ons. Divx HiQ and DivX Plus Web Player HTML5 plug-ins are no longer greyed out, like screenshot below.

There you go folks, high definition videos without the need for flash. HiQ makes it possible to play hi-def videos without taxing your processor. This has been tested to work on both Firefox 4.0.1 and Firefox 5.0. And, for some strange reason now works for Google Chrome 12 too.

A similar tweak was also previously published for .xpi Firefox add-ons. But the same principles apply here. So go ahead and test you favorite add-ons with the latest Firefox 5.0, chances are they might still work.

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