SLANG is a system for accurate measurements of RTT and derived metrics in an IP network.
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garberg Don't sudo when root locks up when started on a node without network connectivity as
sudo tries to reach the LDAP server. To avoid this, as a quick fix, was modified to not run sudo when already logged in as root.
Latest commit 3214b42 Apr 8, 2013
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appliance Don't sudo when root Apr 8, 2013
client Merge branch 'master' of May 25, 2011
debian Bumbed version number and kill probed Dec 9, 2012
manager Various, purely aesthetical, changes Jun 19, 2012
probed Changed sockaddr_in6 to addr_t Aug 20, 2012 Automake, new header style Feb 4, 2011
README Readme Feb 15, 2011


This is SLA-NG's "probed" application, which can be used as a ping tool
(a little bit like iperf) or a an SLA daemon collecting statistics for
many measurement sessions. The authors are of this program is Anders
Berggren <> and Lukas Garberg <>
working for Tele2 <>

In order to compile, you need Linux, libxml2, and pkg-config. In Debian, 
these are installed with (as root)

# apt-get install libxml2-dev pkg-config

You can then compile "probed" (the executable probed/probed) with

$ ./configure
$ make
After compiling, the executable "probed" is found in the folder "probed".
To try it out, start it 

$ probed -c -u

which will use user-land timestamping (-u) to ping itself (-c 
To ping another machine, start it with as a server with

$ probed -s -u

on one machine, and as a client

$ probed -c name-of-server -u

on the other machine. To try out kernel timestamping, you need a kernel
compiled with the configuration option CONFIG_NETWORK_PHY_TIMESTAMPING
and network drivers with timestamp patches. You can do this yourself by
adding "EXPORT_SYMBOL_GPL(skb_clone_tx_timestamp);" to the Linux file 
net/core/timestamping.c and "skb_tx_timestamp(skb);" in the beginning
of the "xmit" function of the driver that you're using. In order to get
hardware timestamping (very accurate!) to work, buy an Intel 82580 NIC,
download the latest Linux kernel, compile it (as noted above) with
CONFIG_NETWORK_PHY_TIMESTAMPING, and check out the Linux netdev thread if you're using 2.6.37 or older.


Q: It doesn't compile!
A: It requires Linux (newer versions), libxml2-dev and pkg-config. If
   you have, please report compile errors to us.

Q: It crashes!
A: Please contact us!

Q: It just says "Connecting to..."! 
A: You need to run probed in server mode (-s) on the other end, and make
   sure that both TCP and UDP on port 60666 (or whatever you choose with
   the flag -p) is open. 

Q: I get TX timestamp errors!
A: You have probably a kernel with CONFIG_NETWORK_PHY_TIMESTAMPING but
   not patched drivers with skb_tx_timestamp. See "RUNNING". Or, you
   have an Intel 82580 and would like to use hardware timestamping, but
   without using a good driver. See
   You also need to be root, in order to use hardware timestamping.

Q: I have checked everything, but still get timestamp errors!
A: Please contact us!