Archive for the ‘Networking’ Category

Hyper-V – Configure The Host to Route Between Virtual Network Subnets

Sunday, October 17th, 2010

2011-01-13 Updated

2010-10-17 Initial Post

Windows Server 2008 R2, Enterprise

I decided to give this another shot today and try to figure out how to create multiple subnets/virtual networks so that I can set up a more realistic AD infrastructure with multiple sites/subnets. (more…)

DHCP Broadcasts, How Routers/DHCP Relay Agents Handle Them

Tuesday, August 24th, 2010

2010-08-24 Initial Post

I've always wondered how a DHCP server is able to communicate with clients on different subnets if both the client and server use broadcasts. Basically, the router (or DHCP relay agent, that's on the client's subnet) intercepts the DHCP broadcasts sent from the client. The router knows that the broadcast is DHCP-related because the destination port is UDP 67, which what the DHCP service listens on.

The router takes the broadcast and "repackages" it as a unicast message to the DHCP server. That part is easy to understand. (more…)

AD DNS Stub Zones, Conditional Forwarders, and Zone Delegation

Tuesday, June 22nd, 2010

2009-09-08 Initial Post

Windows Server 2003/2008


I’ve been working with AD for 9 years and just recently really understood what a stub zone was and which situations are appropriate for its use. I also came to a similar realization about conditional forwarding, although I was already more familiar with that. Anyway, I don’t think many people really understand these features for two major reasons: (more…)

SSL / HTTPS Man-in-the-Middle Attacks

Saturday, February 6th, 2010

2008-12-24 Initial Post

The other month I was wondering if HTTP SSL traffic could be spoofed by some type of man-in-the-middle scenario and just the other day I read an article (more…)

Network Sniffer Limitations

Saturday, February 6th, 2010

2008-12-30 Initial Post

Data travelling in clear text is vulnerable to network sniffers, but technologies such as network switches and VLANs make it difficult to actually sniff all packets. Switches and VLANs contain broadcast traffic. (more…)