This is a set of scripts (sometimes also called "Openscripts") that report, configure and measure (and improve) latency in home routers. These scripts work for OpenWrt and include:
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getstats.sh - a script to collect troubleshooting information that helps to diagnose problems in the OpenWrt distribution.
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opkgscript.sh - a script to save the list of currently-installed packages (say, before a sysupgrade), and then restore the full set of packages after the upgrade.
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config-openwrt.sh - a script to configure the OpenWrt router consistently after flashing factory firmware.
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config-spare-router.sh - Configure a "spare router" to known configuration so it's easy to re-use in a new setting.
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print-router-label.sh - Create a printable label showing LAN address and login credentials that can be taped on the side of the router.
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betterspeedtest.sh & netperfrunner.sh & networkhammer.sh - scripts that measure the performance of your router or offer load to the network for testing.
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idlelatency.sh - a script to measure the latency of an "idle line" without any additional traffic generation from the script.
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tunnelbroker.sh - a script to set up a IPv6 6-in-4 tunnel to TunnelBroker.net.
These scripts can be saved in the /usr/lib/OpenWrtScripts directory.
The easiest way to do this is to ssh into the router and enter these commands:
opkg update
opkg install netperf git git-http
cd /usr/lib
git clone https://github.com/richb-hanover/OpenWrtScripts.gitNB: Some of these scripts have instructions for running the script
from /tmp
The getstats.sh script helps diagnose problems with OpenWrt.
If you report a problem, it is always helpful to include the output of this script.
getstats.sh executes a built-in set of commands and writes the
collected output to /tmp/openwrtstats.txt.
The script also executes commands passed as arguments on the command line.
It also displays a list of user-installed opkg packages -
that is those not installed by default.
In the example below, the output would contain results from the
standard set of commands plus the two additional arguments:
Usage: sh getstats.sh "ls /usr/lib" "ls -al /etc/config"
To install and run this script: The script is self-contained, and can be placed in any directory. Read the top of the getstats.sh file for a simple procedure for using the script.
Sample output file: See a sample output file - openwrtstats.txt
NOTE: This script is deprecated. It still works, but when upgrading to a new OpenWrt release, a far easier option is to use the Attended Sysupgrade in recent versions of OpenWrt.
The opkgscript.sh script helps to restore the current set of packages
after a sysupgrade or even a clean install of either LEDE or OpenWrt.
By default, the write command saves the list of installed packages in
/etc/config/opkg.installed (where it will be preserved across sysupgrades),
and the install command reads the file, to restore that set of packages.
Cloned from Malte Forkel's
original script.
Usage:
sh opkgscript.sh write use before sysupgrade to save the current set of packages
sh opkgscript.sh install use after successful sysupgrade, to restore those packages
sh opkgscript.sh help display full help information for the script
Configure a "spare router" to known settings so that it's easy to use in a new situation. Many of us have a pile of routers that might be passed along to friends, family, or neighbors. But they're in an unknown state, and it's a hassle to figure out the current configuration to reuse them.
This script configures an OpenWrt router to a known state. It also prints a label that can be taped to the outside of the router so the next person "to touch it" can log in easily.
When you're taking a router out of service, install the latest OpenWrt firmware, then run this script. Print the label (below) and tape it to the router. It'll be easy to start using it again. For more details, read Why a "spare router"?
This script retrieves values from an OpenWrt router to create a label that contains the LAN address and important credentials. Tape this label to the side of the router so the next person to encounter the router (which may be you) can access it.
This process is reasonably secure - if the bad guy can read the label, they can also factory-reset the router (or steal your TV or your silverware). Here's a sample label:
======= Printed with: print-router-label.sh =======
Device: Linksys E8450 (UBI)
OpenWrt: OpenWrt 23.05.5 r24106-10cc5fcd00
Connect to: http://Belkin-RT3200.local
or: ssh [email protected]
LAN: 192.168.253.1
User: root
Login PW: abcd9876
Wifi SSID: My Wifi SSID
Wifi PW: <no password>
Configured: 2024-11-28
=== See github.com/richb-hanover/OpenWrtScripts ===
Label for Power Brick: Linksys E8450 (UBI)
The config-openwrt.sh script updates the factory settings of OpenWrt
to a known-good configuration.
If you frequently update your firmware, you can use this script to reconfigure
the router to a consistent state.
You should make a copy of this script, customize it to your needs,
then use the "To run this script" procedure (below).
This script is designed to configure the settings after an initial "factory" firmware flash. There are sections below to configure many aspects of your router. All the sections are commented out. There are sections for:
- Set up the WAN interface to connect to your provider
- Update the software packages
- Update the root password
- Set the time zone
- Enable SNMP for traffic monitoring and measurements
- Enable mDNS/ZeroConf on the WAN interface
- Set the SQM (Smart Queue Management) parameters
[ Note: the remaining items have not been converted to work on OpenWrt yet ]
- Enable NetFlow export for traffic analysis
- Change default IP addresses and subnets for interfaces
- Change default DNS names
- Set the radio channels
- Set wireless SSID names
- Set the wireless security credentials]_
Flash the router with factory firmware. Then telnet/ssh in and execute these statements. You should do this over a wired connection because some of these changes may reset the wireless network.
ssh [email protected]
cd /tmp
cat > config.sh
[paste in the contents of this file, then hit ^D]
sh config.sh
Presto! (You should reboot the router when this completes.)Note: If you use a secondary OpenWrt router, you can create another copy of this script, and use it to set different configuration parameters (perhaps different subnets, radio channels, SSIDs, enable mDNS, etc).
The betterspeedtest.sh script emulates the web-based test performed
by speedtest.net, but does it one better. 1
While script performs a download and an upload to a server on the Internet,
it simultaneously measures latency of pings to see whether the file transfers
affect the responsiveness of your network.
Here's why that's important: If the data transfers do increase the latency/lag much, then other network activity, such as voice or video chat, gaming, and general network activity will also work poorly. Gamers will see this as lagging out when someone else uses the network. Skype and FaceTime will see dropouts or freezes. Latency is bad, and good routers will not allow it to happen.
The betterspeedtest.sh script measures latency during file transfers. To invoke it:
sh betterspeedtest.sh -Z passphrase [ -4 | -6 ] [ -H netperf-server ] [ -t duration ] [ -p host-to-ping ] [ -i ] [ -n simultaneous-streams ]Options, if present, are:
- -H | --host: DNS or Address of a netperf server (default - netperf.bufferbloat.net) Alternate servers are netperf-east (east coast US), netperf-west (California), and netperf-eu (Denmark)
- -4 | -6: Enable ipv4 or ipv6 testing (default - ipv4)
- -t | --time: Duration for how long each direction's test should run - (default - 60 seconds)
- -p | --ping: Host to ping to measure latency (default - gstatic.com)
- -i | --idle: Don't send traffic, only measure idle latency
- -n | --number: Number of simultaneous sessions (default - 5 sessions)
- -Z passphrase: Required to use the default netperf.bufferbloat.net server. Visit the site to get today's value.
The output shows separate (one-way) download and upload speed, along with a summary of latencies, including min, max, average, median, and 10th and 90th percentiles so you can get a sense of the distribution. The tool also displays the percent packet loss. The example below shows two measurements, bad and good.
The Idle test uses the same process to measure latency of the line, but without any additional traffic from this script. It runs for the specified --time.
Note: If the script displays all-zeros for the latency, check these possibilities:
- The named server may be down
- The script may have chosen an IPv6 address when it's not available.
Use the
-4or-6option to force the proper address type.
On the left is a test run without SQM. Note that the latency gets huge (greater than 5 seconds), meaning that network performance would be terrible for anyone else using the network.
On the right is a test using SQM: the latency goes up a little (less than 23 msec under load), and network performance remains good.
Example with NO SQM - BAD Example using SQM - GOOD
root@openwrt# sh betterspeedtest.sh root@openwrt# sh betterspeedtest.sh
[date] Testing against netperf.bufferbloat.net (ipv4) [date] Testing against netperf.bufferbloat.net (ipv4)
with 5 simultaneous sessions while pinging gstatic.com with 5 simultaneous sessions while pinging gstatic.com
(60 seconds in each direction) (60 seconds in each direction)
Download: 6.65 Mbps Download: 6.62 Mbps
Latency: (in msec, 58 pings, 0.00% packet loss) Latency: (in msec, 61 pings, 0.00% packet loss)
Min: 43.399 Min: 43.092
10pct: 156.092 10pct: 43.916
Median: 230.921 Median: 46.400
Avg: 248.849 Avg: 46.575
90pct: 354.738 90pct: 48.514
Max: 385.507 Max: 56.150
Upload: 0.72 Mbps Upload: 0.70 Mbps
Latency: (in msec, 59 pings, 0.00% packet loss) Latency: (in msec, 53 pings, 0.00% packet loss)
Min: 43.699 Min: 43.394
10pct: 352.521 10pct: 44.202
Median: 4208.574 Median: 50.061
Avg: 3587.534 Avg: 50.486
90pct: 5163.901 90pct: 56.061
Max: 5334.262 Max: 69.333
The netperfrunner.sh script runs several netperf commands simultaneously.
This mimics the stress test of
Flent
[Github] but without the nice GUI result.
When you start this script, it concurrently uploads and downloads several streams (files) to a server on the Internet. This places a heavy load on the bottleneck link of your network (probably your connection to the Internet), and lets you measure both the total bandwidth and the latency of the link during the transfers.
To invoke the script:
sh netperfrunner.sh -Z passphrase [ -4 | -6 ] [ -H netperf-server ] [ -t duration ] [ -p host-to-ping ] [-n simultaneous-streams ]Options, if present, are:
- -H | --host: DNS or Address of a netperf server (default - netperf.bufferbloat.net) Alternate servers are netperf-east (East Coast US), netperf-west (California), netperf-eu (Denmark), or flent-fremont (also California)
- -4 | -6: Enable ipv4 or ipv6 testing (default - ipv4)
- -t | --time: Duration for how long each direction's test should run - (default - 60 seconds)
- -p | --ping: Host to ping to measure latency (default - gstatic.com)
- -n | --number: Number of simultaneous sessions (default - 4 sessions)
- -Z passphrase: Required for netperf.bufferbloat.net
See
betterspeedtest.sh
The output of the script looks like this:
root@openwrt:/usr/lib/OpenWrtScripts# sh netperfrunner.sh
[date/time] Testing netperf.bufferbloat.net (ipv4) with 4 streams down and up
while pinging gstatic.com. Takes about 60 seconds.
Download: 5.02 Mbps
Upload: 0.41 Mbps
Latency: (in msec, 61 pings, 15.00% packet loss)
Min: 44.494
10pct: 44.494
Median: 66.438
Avg: 68.559
90pct: 79.049
Max: 140.421Note: The download and upload speeds reported may be considerably lower than your line's rated speed. This is not a bug, nor is it a problem with your internet connection. That's because the acknowledge messages sent back to the sender consume a significant fraction of the link's capacity (as much as 25%).
The networkhammer.sh script continually invokes the netperfrunner script to
provide a heavy load.
It runs forever - Ctl-C will interrupt it.
This script is no longer maintained.
Use the --idle option of the betterspeedtest.sh script.
The tunnelbroker.sh script configures OpenWrt to create
an IPv6 tunnel via Hurricane Electric.
It's an easy way to become familiar with IPv6 if your ISP
doesn't offer native IPv6 capabilities.
There are several steps:
-
Go to the Hurricane Electric TunnelBroker.net site to set up your free account. There are detailed instructions for setting up an account and an IPv6 tunnel in the script itself, or at the IPv6 Tunnel page of bufferbloat.net
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From the tunnelbroker main page, click "Create Regular Tunnel"
- Enter your IP address in "IPv4 Endpoint" (paste in the address you're "viewing from")
- Select a nearby Tunnel Server
- Click "Create Tunnel"
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On the resulting Tunnel Details page, click Assign /48 to get a /48 prefix
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From the Tunnel Details page, copy and paste the matching values into the
tunnel.shfile. The User_Name is the name you used to create the account. Find the Update_Key on the Advanced Tab of the Tunnel Details page. -
ssh into the router and execute this script with these steps.
ssh [email protected] # use the address of your router
cd /tmp
cat > tunnel.sh
[paste in the contents of this file, then hit ^D]
[edit the script to match your tunnelbroker values]
sh tunnel.sh
[Restart your router. This seems to make a difference.]Presto! Your tunnel is up!
Your computer should get a global IPv6 address, and should be able to
communicate directly with IPv6 devices on the Internet.
To test it, try: ping6 ivp6.google.com
Footnotes
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Since the script was created all three of the major speed test sites now include a latency setting. But
betterspeedtest.shstill provides good numerical results. See: ↩