12/28/12

DNS failover solutions

DNS hosts - cheap w/ no failover:
- www.godaddy.com ($3/month)
- aws.amazon.com/route53 (pay as you go)

DNS failover services:
- www.dnshat.com ($20/month) has a very basic interface.  I felt turned off.
- www.totaluptime.com ($40/month) is a nice site.  Offers custom probing, email alerts, and how-to videos.
- www.dnsmadeeasy.com ($30/year for up to 10 domains) looks ideal for my needs.  Failover monitoring is an additional $5/year per hostname.

DNS failover software:
- www.simplefailover.com ($90/one-time, 14 day free trial) is an on-premise program that can monitor the availability of your domains, update them via DNS zone transfer, and email alerts.  It sounds pretty cool.

70-410 - Post 1

Server 2012 is offered in 4 flavors:
- Datacenter ($4,809 retail) allows unlimited VMs on up to two physical processors.
- Standard ($882 retail) allows up to two VMs on up to to physical processors.
- Essentials ($501 retail) replaces SBS, allows up to 25 users, is intended for file or print sharing, Active Directory authentication, DNS, IIS, etc.  However, I can tell you that the Office 365 connector is lame, because when users change their password at a workstation it's not replicated up to Office 365 - only console password resets trigger the replication.
- Foundation (OEM only) is for offices of up to 15 people who only need basic file/print services and Active Directory.

This article explains the differences between Essentials & Foundation.

Microsoft is pushing "Server Core" installations and now lets you flip back & forth between core and GUI mode, so that's cool.

By default, all the server installation files get copied to the WinSxS directory.  If you're tight on space, you can use PowerShell commands to implement "Features on Demand", which removes the source files of features you're not using.

Server 2012 introduces hardware independent NIC teaming for fault tolerance and higher throughput.

The GUI tool "Server Manager" can export its actions as an XML file that show you the Powershell commands it will be executing (and which can be executed as a batch from the CLI).


11/5/12

Learning Server 2012

Server 2012 includes de-duplication for non-boot volumes that are formatted with NTFS (not ReFS).  It runs as a scheduled task.

Parallels Desktop 4 doesn't support Server 2012 as a guest (I tried), but VirtualBox 4.2.4 does.  In fact, VirtualBox blew me away with how refined it is for a free product.  I'm very satisfied with VirtualBox so far.

CHKDSK is enhanced: scanning is done while the server is running and any repairs are attempted at that time; if a repair requires a reboot, CHKDSK only works on the exact problems that were flagged earlier so the server can reboot quickly.

At the Ctrl + Alt + Del login screen, there's a button to show the password you typed in clear-text.

The UI is not pretty, even with the Desktop Experience installed.  Navigation is easy though, you hit the Windows key on your keyboard and then start typing just like in Windows 7 to search for what you want.  Alt + F4 is the fastest way to reboot.  How to navigate the new UI.  Keyboard shortcuts.

Active Directory now has a feature called VM-GenerationID so we can roll-back a virtualized domain controller to an earlier snapshot without messing up Active Directory replication.

10/13/12

NPS Error

Sonicwall VPN users, authenticated by NPS on an SBS 2011 server, were getting "Error 812" when they tried to connect - "The connection was prevented because of a policy configured on your RAS/VPN server..." 

The Security Event Log on the server reported Event ID 6273 - Reason Code: 65.  The Network Access Permission setting in the dial-in properties of the user account in Active Directory is set to Deny access to the user.

This was resolved by deleting and recreating the Network Policy in NPS.

7/15/12

Softphone wouldn't register with AsteriskNOW

Situation: AsteriskNOW is running in a Parallels virtual machine on my laptop.  A hardware phone registers to it just fine, but a soft phone won't.  Why?  Because the virtual machine was using bridged networking.  Switching to shared networking fixed the problem.  Along the way, I learned two interesting commands.

Here's how to see all the UDP port bindings in CentOS:

[root@localhost ~]# netstat -apnu
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
udp 0 0 0.0.0.0:53 0.0.0.0:* 2774/dnsmasq
udp 0 0 0.0.0.0:33590 0.0.0.0:* 2754/avahi-daemon
udp 0 0 0.0.0.0:961 0.0.0.0:* 2057/rpc.statd
udp 0 0 0.0.0.0:5060 0.0.0.0:* 2680/asterisk
udp 0 0 0.0.0.0:964 0.0.0.0:* 2057/rpc.statd
udp 0 0 0.0.0.0:68 0.0.0.0:* 1791/dhclient
udp 0 0 0.0.0.0:4569 0.0.0.0:* 2680/asterisk
udp 0 0 0.0.0.0:5353 0.0.0.0:* 2754/avahi-daemon
udp 0 0 0.0.0.0:111 0.0.0.0:* 2017/portmap
udp 0 0 :::53 :::* 2774/dnsmasq
udp 0 0 :::41040 :::* 2754/avahi-daemon
udp 0 0 :::5353 :::* 2754/avahi-daemon

Here's how to see what, if anything, is using a particular port:

[root@localhost ~]# lsof -i:5060
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
asterisk 2680 asterisk 14u IPv4 7935 0t0 UDP *:sip