There are a number of ways to troubleshoot network connections on (or using) an iOS device. These can be common troubleshooting steps that you might run from the command line or a third party app on a desktop computer or they could be specific to testing the network environment for an iOS device. Some of these apps are even free. Ping Lite One of the most common tasks that most administrators routinely do to test both DNS resolution and connectivity is pinging something. Ping Lite comes with a function to show your IP, a ping tool, a tool to ping the subnet, the ability to run trace routes and for…
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How Exchange's Autodiscover Works With Mail.app
Autodiscover automatically configures profile settings for Exchange clients. These clients include Microsoft Outlook 2007 or Outlook 2010, Outlook for Mac, Mail.app in Mac OS X, iPhone, iPad and ActiveSync enabled phones. Autodiscover is often made out to be complicated. There’s an Autodiscover service that gets installed when a Client Access Server (CAS) role is setup for Exchange 2010 in the form of a default virtual directory named Autodiscover for the default Web site in Internet Information Services (IIS). You then forward an autodiscover service locater record in DNS in the form of _autodiscover._tcp. The virtual directory handles Autodiscover requests. But what about other vendors, and even for Exchange, how do…
- Mac OS X, Mac OS X Server, Mac Security, Mass Deployment, Network Infrastructure, Unix, Windows Server
"Don't Go Near There": Sponsored Top Level Domain Names
Any time I think of something you’re not supposed to do with network architecture, I always think of Good Morning Vietnam. When Robin Williams says: “Don’t go near there!” But Betty! “Don’t go near there…get away from the river! Stay away from there!” One of the things you’re not supposed to do on networks is have conflicting DNS information. One example is to use a www record on one DNS server and a different one on another DNS server. This introduces a potential problem when some users end up with one DNS server and others end up with another. IP, DNS and other conflicts are usually a bad thing. Another…
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Big Changes in Lion Server
OK, by now I’m sure everyone has heard that OS X Server is a download off the App Store. For a whoppin’ $50 you get the OS that was once called “Open Source Made Easy” until someone at Apple realized that GPLv3 might mean that Open Source doesn’t always mean “free as in beer”. Wait, did I say that out loud? Point is, there are bigger changes here than just moving the server to the App Store. There are also some pretty big changes to the GUI of OS X Server. The first and most obvious is the LoginWindow, which is different in OS X in general. It obviously looks…
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When Zones Just Won't Die
At times, you may find that information gets stuck in Server Admin and can’t be removed. For example, you see a Zone in Server Admin, and it doesn’t have a Name Server record attached to it. You can’t delete it but every time you add a Name Server it just disappears. This is often caused when you remove or change something and it gets dumped from the zone files in /var/named but not from the BIND view. Running serveradmin will show the data but as it’s serialized it can’t be removed: serveradmin settings dns Without a Name Server record, the zone is unresponsive to queries. Removing the zone can delete the…
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Adding Recursion in named.conf
In DNS, recursion references the process where a name server will make DNS queries to other name servers on behalf of client systems. Most name servers are simply DNS clients that cache information for a specified amount of time. Recursion is disabled by default on most name servers. In Mac OS X recursion is enabled for subnets local to the server only. In environments where you wish to provide recursive queries you can enable recursion by opening Server Admin, clicking on the disclosure triangle for the server you will be configuring and then clicking on the DNS service. From here, click on the Settings icon in the Server Admin toolbar…
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Migrating Mail to Google Apps from cPanel
If you have a web host that supports cPanel (a number do) then moving to Google Apps for Mail couldn’t be simpler. Just log in to your cPanel account and click on the Mail icon in the top left corner. From here, click on the last item in the list, Modify Mail Exchanger (MX Entry). Then click on change an MX Entry. In the Change MX for… drop down list, select the appropriate domain (if you only have one then there should be only the one to change and then enter aspmx.l.google.com in the to: field, clicking Change when you are done. According to the TTL value you will then…
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Using OpenDNS for Web Content Filtering
OpenDNS is a great tool for free (kinda’), community managed web content filtration. We see this used more in education customers than corporate customers, but essentially you point your DNS at them (or your DNS servers as the case may be) and they filter out different kinds of content. As is often the case with free apps, you’re not going to get all the features you might get with some other applications, but OpenDNS is a great start, especially if you’re not currently doing any kind of filtering. To integrate it is very straight forward: sign up for a free account and define the address for your network in their…
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Botnets and Fast Flux
Ever get the call from an ISP that a host on a network you own (no, not p0wn) is hosting a phishing scam site and you need to fix it? Happens all the time for one reason or another. But if the sites that contain malware and phishing information are quickly repaired (and at this point they are due to some really nice advanced systems for handling this kind of thing that are being employed by universities, ISPs and corporations), why bother? Well, this is where Fast flux comes into play. Fast flux is a DNS technique used to hide compromised hosts behind a rapidly changing (thus the word fast…
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OpenDNS
Many people still use 4.2.2.2, 4.2.2.1, 206.13.28.12, 206.13.30.12, or some other arbitrary set of DNS servers. But, these are ISP DNS servers and so subject not only to filtration of source IP addresses at the will of the ISP (which happened back in the old Mindspring days) but also subject to spikes in traffic making someone’s Internet connection appear dog slow. So I’ve been putting people on internal DNS servers for a long time. But even they need to point somewhere for their DNS… Enter OpenDNS. These guys use 208.67.222.222 and 208.67.220.220. They’re free for just doing Internet lookups and if you find you want them to do more for you, they…