Upgrading the TP-Link Archer C5 (v1.2) to an Archer C7 (v2.0)

I own a TP-Link Archer C5 router, version 1.2 – which is identical to the TP-Link Archer C7, version 2.0, save for some limitations which are introduced through software. These limitations include a 300Mbps cap on 2.4GHz (450Mbps for the C7) and a 876Mbps cap on 5GHz (1300Mbps on the C7). Not that much, but still enough to be worth tinkering for.
Since I was looking at increasing the WiFi speeds in my home, I searched around a bit, and found out on Stefan Thesen’s blog and Hagensieker’s blog that it is perfectly possible :)

First, make sure you definitely have an Archer C5 version 1.2, with three antennas. Don’t even try with another version. If it breaks, noone is to blame but you.

You’ll need to flash DD-WRT, OpenWRT or LEDE-Project (check the respective projects for instructions on how to do that) first.

Next, download an Archer C7 firmware from the TP-Link website. I downloaded version 3.14.1 (141110) – which contains the firmware in the file ArcherC7v2_v3_en_3_14_1_up_boot(141110).bin

Now, remove the first 256 bytes, which is the bootloader (which we don’t need to flash it):  dd if=ArcherC7v2_v3_en_3_14_1_up_boot(141110).bin of=tplink_mod.bin skip=257 bs=512 (In case you don’t trust doing it yourself, you can also download the firmware from the blog of Stefan)

Next, you can transmit this (using SFTP) to your router, and then force flash it: sysupgrade -F /tmp/tplink_mod.bin. This will flash the firmware, and reboot the router. You’ll have to reconnect to it (default IP address is 192.168.0.1) and the web interface should report an Archer C7 :)

Afterwards you can either upgrade to the latest C7 firmware, or whichever 3rd party firmware you want. I reflashed to LEDE-Project.

Initial testing showed an improvement in WiFi throughput speeds – so I’m happy with my ‘new’ C7 :)

Managing TP-Link easy smart switches from Linux

I’ve recently acquired some TP-Link ‘Easy Smart’ managed switches – cheap, decently built (metal casing), and a lot of features above the usual unmanaged stuff:

  • Effective network monitoring via Port Mirroring, Loop Prevention and Cable Diagnostics
  • Port and tag-based QoS enable smooth latency-sensitive traffic
  • Abundant VLAN features improve network security via traffic segmentation
  • IGMP Snooping optimizes multicast applications

Unfortunately, it uses a windows application to manage the switches – the 5 and 8 port varieties don’t have a usable built-in web server to manage them. Luckely, there’s a way to make that still work on Linux ;) as it seems that it’s just a JavaFX application. The only thing you’ll ever need a windows installation for (or use Wine) is to install the actual application.

After installation, You’ll find a file called “Easy Smart Configuration Utility.exe” in the installation path. Copy that to your Linux installation, rename to .jar, and you’re good to go.

To run it, you’ll also need the Oracle Java distribution, as JavaFX is not yet part of OpenJDK. Install that in your distribution of choice, and you’ll be able to start the application using java -jar “Easy Smart Configuration Utility.jar” and it’ll start right up.

tplink_easysmart

Unfortunately, it doesn’t work out of the box. The tool doesn’t find any devices on the network, but they are there.
Checking with netstat, the tool bound itself on UDP port 29809, on the local ip address.

$ PID=$(pgrep -f "java -jar Easy Smart Configuration Utility.jar"); netstat -lnput | grep -e Proto -e $PID

Proto  Recv-Q  Send-Q  Local Address            Foreign Address  State  PID/Program name 
udp6   0       0       [your ip address]:29809  :::*                    28529/java

Checking with tcpdump showed that the traffic was returning, but since our tool is only listening on the local ip, and not the UDP broadcast address, it never sees anything.

# tcpdump udp port 29809
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on wlp1s0, link-type EN10MB (Ethernet), capture size 262144 bytes
09:35:48.652235 IP [your ip address].29809 > 255.255.255.255.29808: UDP, length 36
09:35:48.961586 IP [switch ip address].29808 > 255.255.255.255.29809: UDP, length 159

It seems the tool binds to the local IP instead of the ‘any ip’, 0.0.0.0, so you need to locally forward the traffic incoming on the port to your local ip. To do this, execute this command (and/or add it to your local firewall script):

# iptables -t nat -A PREROUTING -p udp -d 255.255.255.255 --dport 29809 -j DNAT --to [your ip address]:29809

And don’t forget to enable IP forwarding

# echo 1 > /proc/sys/net/ipv4/ip_forward

Now you should be able to find and configure the switches in your local network.

OpenWRT, dual routers, dual SSIDs and VLANS

Back in the day I used to have one router in the house: the D-Link DIR-825, flashed with OpenWRT. Configured with two SSIDs – one for internal network use, and one for guest access – the latter being separate from the internal network of the flat.

After moving to our house, I discovered that the house construction materials provide a better shielding for radio signals, which in turn meant that the reach of my WiFi router wasn’t quite what it should be to reach the far corners of the place. I tried increasing the output wattage, but that had only a marginal increase in reach. So in the end I opted getting a new primary router – the TP-Link Archer C5 (though mine has three antennas?), which was promptly reflashed with OpenWRT. The DIR-825 was moved to the opposite corner of the house to increase reach, and at the same time I lowered the output wattage of the radios.
Because of time constraints, I didn’t bother stretching the guest wifi to the second router, as it requires a bit more configuration to properly separate the flows of data between the two networks: vlan configuration.

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