Using Flent to Generate Traffic

Install packages required to run Flent on Fedora-39 (also works on Fedora-36).
1. Install flent - installing flent will also install dependencies netperf, netserver, fping and irtt
  sudo dnf install flent
Install packages from source when required to run Flent on Fedora-30.
Additional packages may need to be installed. See flent.org for more info.
1. Install automake and texinfo
  sudo dnf install automake texinfo autoconf autotools-dev kernel-devel
2. Flent
  git clone https://github.com/tohojo/flent.git
  cd flent
  git checkout v1.3.2
  sudo python3 setup.py install
3. Flent GUI - only necessary to view flent output graphs
  sudo dnf install python3-matplotlib python3-matplotlib-qt5
  sudo dnf install python3-qt5 python3-PyQt5 python3-QtPy
4. Netperf/Netserver
  git clone https://github.com/HewlettPackard/netperf.git
  cd netperf
  sudo ./autogen.sh
  sudo ./configure --enable-demo=yes
  sudo make
  sudo make install
5. Fping
  git clone https://github.com/schweikert/fping.com
  cd fping
  git checkout 3.6
  sudo ./autogen.sh
  sudo ./configure
  sudo make
  sudo make install
6. Iperf2 - Required for the --enhanced option which will display enhanced output in reports.
  dnf install iperf

To view a list of possible Flent tests, or run Flent by command line, open a terminal window.

[lanforge@ct523c-0b29 ~]$ flent --list-tests 
Available tests: 
bursts                     :  Latency measurements under intermittent UDP bursts 
bursts_11e                 :  802.11e Latency measurements under intermittent UDP bursts 
cisco_5tcpup               :  RTT Fair Realtime Response Under Load 
cisco_5tcpup_2udpflood     :  Cisco 5TCP up + 2 6Mbit UDP 
cubic_bbr                  :  Cubic VS BBR smackdown 
cubic_cdg                  :  Cubic VS CDG smackdown 
cubic_dctcp                :  Cubic VS DCTCP smackdown 
cubic_ledbat               :  Cubic VS Ledbat smackdown 
cubic_ledbat_1             :  Cubic vs LEDBAT upload streams w/ping 
cubic_reno                 :  Cubic VS Reno smackdown 
cubic_westwood             :  Cubic VS Westwood 
dslreports_8dn             :  8 down - dslreports dsl test equivalent 
http                       :  HTTP latency test 
http-1down                 :  HTTP get latency with competing TCP download stream 
http-1up                   :  HTTP get latency with competing TCP upload stream 
http-rrul                  :  HTTP get latency with competing RRUL test 
iterated_bidirectional     :  Iterated TCP bidirectional transfers example 
ledbat_cubic_1             :  Cubic vs LEDBAT upload streams w/ping 
ping                       :  Ping test (ICMP and UDP) 
qdisc-stats                :  Capture qdisc stats 
reno_cubic_westwood_cdg    :  Realtime Response Under Load 
(with different congestion control algs) 
reno_cubic_westwood_ledbat :  Realtime Response Under Load 
(with different congestion control algs) 
reno_cubic_westwood_lp     :  Realtime Response Under Load 
(with different congestion control algs) 
rrul                       :  Realtime Response Under Load 
rrul46                     :  Realtime Response Under Load - Mixed IPv4/6 
rrul46compete              :  Realtime Response Under Load - Mixed v4/v6 compete 
rrul_100_up                :  100 up vs 1 down - exclusively Best Effort 
rrul_50_down               :  50 down vs 1 up - exclusively Best Effort 
rrul_50_up                 :  50 up vs 1 down - exclusively Best Effort 
rrul_be                    :  Realtime Response Under Load - exclusively Best Effort 
rrul_be_iperf              :  Realtime Response Under Load - exclusively Best Effort (Iperf TCP) 
rrul_be_nflows             :  Realtime Response Under Load - Best Effort, configurable no of flows 
rrul_cs8                   :  Realtime Response Under Load CS8, one flow per CS/precedence level 
rrul_icmp                  :  Realtime Response Under Load - Best Effort, only ICMP ping 
rrul_noclassification      :  Realtime Response Under Load - no classification on data flows 
rrul_prio                  :  Realtime Response Under Load - Test Prio Queue 
rrul_torrent               :  Torrent-like competition 
rrul_up                    :  Realtime Response Under Load - upload only 
rrul_var                   :  Realtime Response Under Load - variable configurable streams 
rtt_fair                   :  RTT Fair Realtime Response Under Load 
rtt_fair4be                :  RTT Fair Realtime Response Under Load 
rtt_fair6be                :  RTT Fair Realtime Response Under Load 
rtt_fair_up                :  RTT Fair upstream only 
rtt_fair_var               :  RTT Fair - variable number of hosts 
rtt_fair_var_down          :  RTT Fair - variable number of hosts (download only) 
rtt_fair_var_mixed         :  RTT Fair - variable number of hosts (mixed up and down) 
rtt_fair_var_up            :  RTT Fair - variable number of hosts (upload only) 
sctp_vs_tcp                :  SCTP vs TCP 
tcp_12down                 :  TCP download - 12 streams w/ping 
tcp_12up                   :  TCP upload - 12 streams w/ping 
tcp_1down                  :  Single TCP download stream w/ping 
tcp_1up                    :  Single TCP upload stream w/ping 
tcp_1up_noping             :  Single TCP upload stream 
tcp_2down                  :  TCP download - 2 streams w/ping 
tcp_2up                    :  TCP upload - 2 streams w/ping 
tcp_2up_delay              :  Two TCP upload streams; 2nd stream started delayed 
tcp_2up_square             :  Two TCP upload streams; 2nd stream started delayed 
tcp_2up_square_westwood    :  Two TCP upload streams; 2nd stream started delayed 
tcp_4down                  :  TCP download - 4 streams w/ping 
tcp_4up                    :  TCP upload - 4 streams w/ping 
tcp_4up_squarewave         :  Four TCP upload streams; 2nd streams started delayed, cubic vs BBR 
tcp_6down                  :  TCP download - 6 streams w/ping 
tcp_6up                    :  TCP upload - 6 streams w/ping 
tcp_8down                  :  TCP download - 8 streams w/ping 
tcp_8up                    :  TCP upload - 8 streams w/ping 
tcp_bidirectional          :  Bidirectional TCP streams w/ping 
tcp_download               :  TCP download stream w/ping 
tcp_ndown                  :  TCP download - N streams w/ping 
tcp_nup                    :  TCP upload - N streams w/ping 
tcp_upload                 :  TCP upload stream w/ping 
tcp_upload_1000            :  1000 up - exclusively Best Effort 
tcp_upload_prio            :  TCP upload stream w/ToS prio bits 
udp_flood                  :  UDP flood w/ping 
udp_flood_var_up           :  UDP flood w/ping - variable number of hosts 
udp_flood_var_up_stagger   :  UDP flood w/ping - variable number of hosts, staggered start 
voip                       :  VoIP one-way stream test 
voip-1up                   :  VoIP one-way stream test with competing TCP stream 
voip-rrul                  :  VoIP one-way stream test with competing RRUL test

Enter interface names to be used in Flent tests into the /etc/hosts file.
This is necessary for some of the Flent tools that can only use an interface name rather than IP address.
To run Flent tests by command line:
1. Run netserver. This will start the netserver program which is the traffic server for the other Flent tools specifically netperf.
```
[lanforge@ct523c-0b29 ~]$ netserver
Starting netserver with host 'IN(6)ADDR_ANY' port '12865' and family AF_UNSPEC
```
2. Run one of the available tests. Because LANforge is using vrf, use the vrf_exec.bash script to specify which interface to run the test. The direction of the test is from the perspective of the wired interface. Use the --swap-up-down option to change the direction to the host interface which is the wireless station sta00000 in this example.
To run Flent tests from the LANforge GUI, select the Generic tab from the main GUI window.
Create the Flent netserver.
Here it is useful to create one Generic endpoint to start netserver and one to stop it because the netserver program runs in the background once it is started.
Create the Flent test or tests.
To start any Flent test, start the netserver first, then start the tests one at a time.

Use the Flent GUI to view Flent test results.

[lanforge@ct523c-0b29 ~]$ flent-gui rtt_fair_var-2020-04-15T130555.781338.flent.gz

Use the Flent GUI to compare Flent test results.

[lanforge@ct523c-0b29 ~]$ flent-gui tcp_download-2020-04-15T112442.452934.flent.gz tcp_download-2020-04-15T113910.591355.flent.gz

Flent batch files can be setup to run consecutive and repeated tests.

[lanforge@ct523c-0b29 ~]$ cat flent-batch.txt
 
[Batch::tcp-down]
test_name = tcp_download
hosts = sta00000
title = sta00000-tcp-down rep:${repetition}
filename_extra = sta00000-tcp-down-${repetition}
repetitions = 5
[Batch::tcp-up]
test_name = tcp_upload
hosts = sta00000
title = sta00000-tcp-up rep:${repetition}
filename_extra = sta00000-tcp-up-${repetition}
repetitions = 5
[Batch::rrul]
test_name = rrul
hosts = sta00000
title = sta00000-rrul rep:${repetition}
filename_extra = sta00000-rrul-${repetition}
repetitions = 5\

Flent batch results for rrul.
The rrul test is the Realtime Response Under Load test which attempts to completely use up the link with four upstream TCP connections and four downstream TCP connections each with a different IP ToS setting plus ping and UDP to measure latency all running simultaneously for the purpose of exposing bufferbloat in the network under test.
Flent batch results for five rrul repetitions.

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	Network Testing and Emulation Solutions

Using Flent to Generate Traffic

Goal: Set up virtual stations using a LANforge system, connect them to an AP under test, set up Flent, and run tests.