Print This Post
This article assumes you have an understanding of computer networking basics.
Network Address Translation has several advantages but its primary goal is to allow a single Internet IP address to be shared on a network by multiple devices. Your home router has built in NAT capabilities and does all this automatically. It works by your ISP assigning you ONE IP address to your router, NAT then allows multiple computers to access the Internet through this shared IP address. Read More →
Print This Post
In a previous article I explained what PPTP passthrough is and how it works. In this article I will explain why multiple VPN connections fail with certain routers. This issue only affects PPTP connections and it is directly related to PPTP passthrough.
Here is a brief comparison of how NAT handles PPTP VPN connections differently to normal connections. Read the PPTP passthrough link above for more details:
Print This Post
Most computers connect to the Internet through a NAT device (usually a router). PPTP natively doesn’t work with NAT. Since most VPN connections start from behind a router this is a very common problem. PPTP passthrough addresses this by allowing VPN connections to traverse a NAT with ease. NAT (or more specifically PAT) can’t function without the use of ports. It is important you understand how NAT functions and it’s reliance on ports. If unsure I would advise reading up on network address translation first.
NOTE: With some routers multiple VPN connections is not supported. Read More →
Print This Post
Print This Post
Welcome to part 1 in a 3 part series of articles about routers and routing. In part 1 we will cover how routers works, part 2 talks about the routing table and part 3 covers IP routing.
So, how does a router work? Well, before we get into that you should know the basics of what the IP address is, subnet mask and default gateway before continuing. If you don’t have a read of networking basics first. Read More →
Print This Post
I was doing some work recently for a client when I noticed that a login script was failing to map network drives if deployed through group policy. The strange thing is that if I ran the script manually it worked. Also, at other sites this same login script works perfectly fine whether it’s run by itself or deployed through group policy. The only difference I could find was that users were local admins at the site where the script fails. When users are local administrators UAC comes into play. Read More →
Print This Post
Recently I was doing a bit of promotional work for my blog by participating in some IT related forums. I was going through the post as you do when an interesting question came up. The poster was reading up on about DNS Zones, what their purpose is and how they work. He was having trouble understanding the following paragraph in a study book he was reading:
A DNS zone contains all the domain names the domain with the same domain name contains,
except for domain names in delegated subdomains. For example, the top-level
domain ca (for Canada) has subdomains called ab.ca, on.ca, and qc.ca, for the provinces
Alberta, Ontario, and Quebec. Authority for the ab.ca, on.ca, and qc.ca
domains may be delegated to nameservers in each province. The domain ca contains
all the data in ca plus all the data in ab.ca, on.ca, and qc.ca. However, the zone ca
contains only the data in ca (see Figure 2-10), which is probably mostly pointers to
the delegated subdomains. ab.ca, on.ca, and qc.ca are separate zones from the ca
zone.
Can you understand that?? No wonder he was having trouble, Read More →
Print This Post
Print This Post
There are different reason why you may get an access denied error 0x80070005. This particular one and the following fix is only applicable when the following is met:
The error is caused because of a bug in Windows Explorer and how it handles UAC. It is exactly the same reason as to why you get an access denied message when trying to access certain folders you should have access to. In these scenarios you have given the administrators group full control of the folder, you are a member of this group but you still get an access denied message. See the following UAC access denied for the cause and fix. It talks about Explorer having problems accessing certain folders. As shadow copies/previous versions are launched through Explorer it applies to this also.
NOTE: In the article some of the fixes say to modify the permissions on the folders. This is not possible with shadow copies as the folders are stored in a snapshot. Instead you will only be able to apply the fixes that modify UAC behaviour (solutions 3 and 4).
Print This Post
You receive a Windows 7 access denied error when accessing a folder through Windows Explorer even though you have set the permissions correctly. You are an administrator and the administrators groups have full control over the folder but you can’t access it without Windows re-writing the permissions.
The cause of this is because of a new feature in Windows 7 called User Access Control (UAC). It is the combination of UAC and a bug in Windows Explorer that causes the access denied error.
The easiest solution is to simply disable UAC. If this is not possible (for security reasons) then read on for alternatives. Read More →
