Tech » Tom Geraghty

Why you should be using Open DNS

Nov 192011

What is OpenDNS?

Open DNS is a free DNS lookup service, provided as an alternative to using your ISP’s DNS service. It provides additional features for filtering, web security, statistics, and speed improvements. The business collects revenue from adverts served from search pages, and from the enterprise products they offer, which provide more detailed reporting and more granular features. It’s suitable for use by home users and businesses.

Features

Web content filtering by category
Malware url blocking by default
Phishing website protection
Statistics of DNS resolution
Blocking of malware infected devices “phoning home”
Notification of above devices attempting to phone home
Typo correction (e.g. yaho.co.uk will resolve to yahoo.co.uk)
Custom URL whitelists and blacklists
DNS caching – if authoritative DNS fails, requests will resolve to the last good IP address.
Multiple networks on one account
Potential speed improvements
Zero cost

Benefits

An extra layer of web access filtering can block access to websites by category, such as pornography, malware, adware, and others.
Where your web filtering application or server may fail, Open DNS will pick up the slack, and block inappropriate sites, malware, or phishing attacks. This should result in significantly fewer virus infections.
Where a machine is infected, it will not be able to contact malware servers to update itself or spread further (assuming the malware uses DNS to lookup the home servers). Statistics will show you when devices do attempt to contact malware servers, highlighting potential problems with infection.
Staff will be further protected from online scams and phishing attempts, protecting both them and the business.
Easy-to-read and access statistics will show us which domain names are requested most frequently, and at what times of day. It also highlights where local addresses are being incorrectly forwarded, and may aid fault resolution or identification of previously unknown faults.
Typo correction improves the safety of online activity for users, and improves the user experience, potentially resulting in fewer helpdesk calls.
Where an authoritative DNS server fails to resolve a request, Open DNS will use the last known good IP address. This should also protect against malicious DNS attacks, such as that against NetNames earlier this month.
OpenDNS is usually faster than ISP DNS servers, resulting in an improved user experience.

Opening multiple calendars with Outlook 2003 and Exchange 2010

Tech No Responses »

Aug 082011

Due to the way Outlook 2003 interacts with Exchange 2010, if a user on outlook 2003 tries to open multiple shared calendars, they may receive an error:

“The action could not be completed. The connection to the Microsoft Exchange Server is unavailable. Outlook must be online or connected to complete this action.”

This is because outlook 2003 has to open multiple mapi connections to exchange 2010 for each calendar, and in doing so, hits the default limit of concurrent connections set in the default throttling policy (20). This problem occurs due to Outlook 2003 dependencies on reference Mailbox Database support, which is not supported in Exchange Server 2010. Outlook 2003 clients must now reference the Exchange Server 2010 Address Book service when they open shared calendars.

Usually, restarting outlook provides a temporary fix, but as more mapi connections are created, the limit is reached again.

Using Exchange Shell, I created a new throttling policy with a maximum of 40 concurrent connections.

To create a new policy:

New-ThrottlingPolicy <policyname> -RCAMaxConcurrency 40

Check the details of the policy:

```
get-throttlingpolicy <policyname>
```

Check the user has the default policy applied already:

```
Get-Mailbox -Identity <username> | fl
```

To apply it to a user:

set-mailbox -identity <username> -throttlingpolicy <policyname>

Then test opening multiple calendars.

There is actually a registry key that sets a limit on the Exchange Information store, at 32 connections, so without changing this, clients will still be limited in the number of calendars they can open, but it looks like 32 connections is enough to open 5-6 calendars.

If you were to change these registry keys, they are:

Maximum Allowed Sessions Per User
Maximum Allowed Service Sessions Per User

Today’s illegal downloaders are the entertainment industry execs of the future.

Tech 1 Response »

Mar 142011

The entertainment industry has been slow to embrace the internet, and it’s fair to say that it still hasn’t got its head around a business model that enables consumers to purchase music and films at a reasonable price, online, and without heavy-handed restrictions on use.

itunes was (is) only successful because it’s easy to use. For people with one computer, one iphone or ipod, and an itunes account, it’s the easiest way in the world to purchase music and film downloads online. However, if you have more than one computer, and/or more than one playback device, the DRM imposed upon itunes downloads restricts your use and enjoyment of your purchase measurably. The alternatives are to use Amazon, play.com, or another DRM-free download outlet, or simply use a P2P “illegal” download service. Frequently, due to the technology behind P2P / torrent downloads, it’s also the quickest way to get hold of digital media. This is patently absurd. I can think of no other product where the “free” version is easier to get hold of and easier to use than any paid-for option.

Note: I’m not endorsing illegal downloading, simply stating that if it’s as easy, or easier, than paid-for downloads, people are going to do it. Make paid-for downloads more attractive by removing DRM, introducing an easy, more universal, very fast method of purchase and download, and look at other ways of adding value (bonus content, concert tickets, graphics and other media), and people will pay for them.

The music and film industry simply don’t understand the new business models, or are not willing to change their own. Instead, they foist anti-piracy adverts onto rental and purchased DVDs (Why?! I’ve just paid for it after all.), they add DRM to their own products, making them more difficult to use (the king of “anti-features”), they hunt down file-sharers and threaten them with court cases, and they insist on sticking by their mantra that one illegal download equals one lost sale (if you were let loose in a sweet shop and told it was all free, you’d grab more than if you were paying for the stuff, right?).

Of course, it’s not all bad. The people that are using P2P and torrent technology to acquire digital media today are the business and entertainment industry executives of the future, and they will understand this technology and these business models better than anyone in the industry at the moment. Maybe we’ll soon see a fresh wave of new businesses, new record labels, new legal download outlets, and an industry that sees its customers as valued clients, rather than a thorn in its side.