5333 private links
I love fussing with wifi, but when I’m building the backbone of my network in a new location—a house, apartment, or wherever—I tend to go wired as much as I can. Wireless bridges and tri-band mesh/extender setups are great and convenient, but I always appreciate the stability and speed of an Ethernet cable. //
When I recently offered to help my friends set up their house with a wired backbone, I came across a fun problem: No Ethernet connections in any of their rooms. //
The ingenious solution to this problem? MoCA, or “Multimedia over Coaxial.” I’ve known about the technology for a long time, but never had the time (or need) to play with it until now. My friends’ house was wired with coaxial cables in every room, which made this an ideal solution. I could just use MoCA instead of Ethernet—MoCA 2.0, technically, which gives up to a full gigabit worth of speed and should be more than adequate //
I got my hands on a two-pack of TrendNET TMO-311C2K adapters and got to work, which took all of five minutes because I was acting the fool. It should come as little surprise that plugging in the MoCA adapters to various coaxial ports around the house achieved absolutely nothing. //
That’s just one big way to say that I wasn’t too surprised to find that many of the coaxial cables around my friends’ house simply weren’t connected to anything. I was eventually able to confirm this by tracing the wires to the outside of the house, where I found where all the disconnected cables terminated. I then went and picked up one of these to test which cable went to which room in the house:
https://www.trendnet.com/support/support-detail.asp?prod=105_TMO-311C2K
A smartphone connected Ethernet network analyzer & cable tester that fits into your pocket
The Swiss Army Knife for IT admins
Pockethernet is here to help any IT admin dealing with Ethernet network installation and maintenance. It lets you check the ethernet link, find cable faults, PoE voltage, VLAN, DHCP results and much more with the press of a button. Finished? Then export those results in a detailed measurement report and send them to yourself or your client.
Pockethernet comes with 20+ Features that are essential for anybody working with Ethernet networks.
- Wiremap including shield
- TDR
- Graphical TDR
- Network discovery (CDP, LLDP)
- Voltage detection
- PoE supply detection
- Cable toner with customizable tones
- Generate PDF reports
Disabling LSO on Windows Server 2008 and higher
This is easily done using a NETSH command:
netsh interface tcp set global chimney=disabledDisabling LSO on the Ethernet adapter
This works in all versions of versions of Windows Server since it's done at the driver level. Go to where the network adapters are located in the Control Panel. For Windows Server 2003, this will be under Network Connections. For Windows Server 2008, this will be under Network and Sharing Center –> Change Adapter Settings.
Now right-click on the network adapter and choose Properties from the pop-up menu. At the top of this windows will be a "Connect using" text field with the vendor and model of the network adapter. For my example, I'm using an Intel 52575 Gigabit adapter. Just below this text field, click on the Configure button.
Now click on the Advanced tab, which shows the configurable properties for the adapter. Find the entry for Large Send Offload. This is how it's labeled on Intel adapters, but will vary (sometimes wildly) for adapters from other other vendors. If it's modern adapter like this one, there will be a setting for both IPv4 and IPv6. For older adapters, there will only be a setting for IPv4. Change the value for Large Send Offload from "Enabled" (or "On") to "Disabled" (or "Off") and click on OK.
One issue that I continually see reported by customers is slow network performance. Although there are literally a ton of issues that can effect how fast data moves to and from a server, there is one fix I've found that will resolve this 99% of time — disable Large Send Offload on the Ethernet adapter.
So what is Large Send Offload (also known as Large Segmetation Offload, and LSO for short)? It's a feature on modern Ethernet adapters that allows the TCP\IP network stack to build a large TCP message of up to 64KB in length before sending to the Ethernet adapter. Then the hardware on the Ethernet adapter — what I'll call the LSO engine — segments it into smaller data packets (known as "frames" in Ethernet terminology) that can be sent over the wire. This is up to 1500 bytes for standard Ethernet frames and up to 9000 bytes for jumbo Ethernet frames. In return, this frees up the server CPU from having to handle segmenting large TCP messages into smaller packets that will fit inside the supported frame size. Which means better overall server performance. Sounds like a good deal. What could possibly go wrong?