How to force a Wi-Fi USB adapter on a Synology DiskStation to use 5GHz ac from 2.4GHz

Useful if your SSIDs are identical for 5GHz and 2.4GHz. Having your SSIDs setup like this seems to confuse Synology DSM, and for me it would always connect to the 2.4GHz network.

I had this particular issue where my TP-Link T4U ac wifi adapter for my Synology kept dropping down to using the 2.4GHz network, which slows it down dramatically.

To fix this, here’s what I did. Your mileage may vary, and you may end up disconnecting your Synology from the network, so make sure you have another way of getting to it (such as Ethernet) before proceeding with any of this!

SSH to the DiskStation, login as admin.

sudo -s to root account (same password as admin account)

Make a copy of your existing wifi config file inside /usr/syno/etc/wifi/

For me, I did:

Edit the original file with vi. If you don’t know how to use vi, do a web searhc (it’s not hard, but not easy either).

What you need to do is remove reference to the 2.4ghz network, which you can identify from the bssid, which is the MAC address of your router’s 2.4ghz radio. Once you’re done, the file should just contain details for the bssid that’s your 5ghz network. On my router, the MAC address for the 5GHz network was one hex number higher than the 2.4GHz network.

Next, make a copy of the wpa_supplicant file in /usr/syno/etc. For me, this was called: wpa_supplicant.conf.wlan0

Now edit the file, and change the bssid (which will be the 2.4ghz bssid MAC address) to the bssid MAC address of the 5ghz network.

Reboot the Synology diskstation, and when it comes back, it should be on the 5GHz network.

Install and run Wireshark on the command line (CentOS 5.2)

Using CentOS 5.2 or Red Hat Enterprise Linux 5, install and run Wireshark (formerly Ethereal) over the command line.

Install Wireshark:

Run a capture:

This command will run Wireshark/Ethereal, capture on the eth1 interface and output the data to /yourhomedir/mycapture.pcap

Why would you want to do this? If you want to capture packets from a headless or remote Linux PC and analyse the data elsewhere.

Right now I’m at home, but I have a headless CentOS box at work that’s running ntop from a mirrored port, in order to look at network traffic flowing over the router. To increase the capability of the CentOS box, I want to use it to capture packets using Wireshark, then download the .pcap file over WinSCP and look at the data on my laptop using Wireshark for Windows.

A TV that can play from USB Mass Storage devices

The more I play video content from a USB stick on the Xbox 360, the more I want a TV that can play content directly from a USB Mass Storage Device.

Surely it can’t be that hard? I’m thinking possibly something like a tiny Linux distribution embedded into the TV, something akin to the “Instant Play” feature on many laptops.

$100 laptop is to get a revamp

Seems the OLPC project is going to be revamping their XO laptop. Looks pretty good, and cheaper too!

Control user access to SSH

Got a shiny new Linux box on your network but don’t want all your users connecting to it via SSH? Control access by editing the SSH configuration file and using the AllowUsers directive like so:

To add multiple entries, either separate users with a space, or write an entirely new line: