Htb

The following scenario shows how to configure a HTB qdisc.

../../../../../_images/topology1.svg

Test HTB QDisc

Description

In this scenario, a Hierarchy Token Bucket (HTB) qdisc is configured in DUT0 (‘eth0’ interface) to achieve linksharing among a hierarchy of classes. Three classes are created with different matches (filters). Each match is allocated to a single class and evaluated in order.

Scenario

Step 1: Set the following configuration in DUT0:

set interfaces ethernet eth0 address 10.0.0.2/24
set interfaces ethernet eth0 traffic control out QDISC
set traffic control QDISC type htb bandwidth 100
set traffic control QDISC type htb class 1 bandwidth percentage 50
set traffic control QDISC type htb class 1 ceiling percentage 100
set traffic control QDISC type htb class 2 bandwidth percentage 20
set traffic control QDISC type htb class 2 ceiling percentage 0
set traffic control QDISC type htb class 3 bandwidth percentage 10
set traffic control QDISC type htb class 3 ceiling percentage 0
set traffic control QDISC type htb match 1 class 1
set traffic control QDISC type htb match 1 ip destination port 8080
set traffic control QDISC type htb match 2 class 2
set traffic control QDISC type htb match 2 ip protocol tcp
set traffic control QDISC type htb default-class 3

Step 2: Set the following configuration in DUT1:

set interfaces ethernet eth0 address 10.0.0.1/24

Step 3: Ping IP address 10.0.0.1 from DUT0:

admin@DUT0$ ping 10.0.0.1 count 1 size 56 timeout 1
Show output
PING 10.0.0.1 (10.0.0.1) 56(84) bytes of data.
64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=0.449 ms

--- 10.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.449/0.449/0.449/0.000 ms

Step 4: Initiate a bandwidth test from DUT0 to DUT1

admin@DUT1$ monitor test performance server port 8080
admin@DUT0$ monitor test performance client 10.0.0.1 duration 5 port 8080
Expect this output in DUT0:
Connecting to host 10.0.0.1, port 8080
[  5] local 10.0.0.2 port 58864 connected to 10.0.0.1 port 8080
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.47   sec  10.9 MBytes  62.4 Mbits/sec    0    189 KBytes
[  5]   1.47-2.00   sec  7.77 MBytes   123 Mbits/sec    0    257 KBytes
[  5]   2.00-3.00   sec  5.59 MBytes  46.9 Mbits/sec    0    334 KBytes
[  5]   3.00-4.00   sec  8.20 MBytes  68.8 Mbits/sec    1   1.41 KBytes
[  5]   4.00-5.00   sec  12.0 MBytes   101 Mbits/sec    0    355 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-5.00   sec  44.5 MBytes  74.7 Mbits/sec    1             sender
[  5]   0.00-5.00   sec  42.8 MBytes  71.8 Mbits/sec                  receiver

iperf Done.

Step 5: Initiate a bandwidth test from DUT0 to DUT1

admin@DUT1$ monitor test performance server port 1234
admin@DUT0$ monitor test performance client 10.0.0.1 duration 5 port 1234
Expect this output in DUT0:
Connecting to host 10.0.0.1, port 1234
[  5] local 10.0.0.2 port 48832 connected to 10.0.0.1 port 1234
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  2.68 MBytes  22.4 Mbits/sec    8   66.5 KBytes
[  5]   1.00-2.00   sec  2.42 MBytes  20.3 Mbits/sec    0   66.5 KBytes
[  5]   2.00-3.00   sec  2.24 MBytes  18.8 Mbits/sec    0   66.5 KBytes
[  5]   3.00-4.00   sec  2.17 MBytes  18.2 Mbits/sec    0   66.5 KBytes
[  5]   4.00-5.00   sec  2.49 MBytes  20.9 Mbits/sec   12   32.5 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-5.00   sec  12.0 MBytes  20.1 Mbits/sec   20             sender
[  5]   0.00-5.00   sec  11.4 MBytes  19.1 Mbits/sec                  receiver

iperf Done.

Step 6: Run command traffic control show at DUT0 and check if output contains the following tokens:

class 1
class 2
class 3 (default)
Show output
Traffic control for interface 'eth0' - 'egress' mode

------------------------------------------------------------------------------------
ID   traffic control        type         parent  bytes sent  pkts sent  pkts dropped
------------------------------------------------------------------------------------
1:0  QDISC            htb                root      59677315      39464             3
1:1  QDISC            class 1            1:0       47162981      31171             0
1:2  QDISC            class 2            1:0       12513628       8286             0
1:3  QDISC            class 3 (default)  1:0            706          7             0
2:0  -                fq_codel           1:1       47162981      31171             0
3:0  -                fq_codel           1:2       12513628       8286             3
4:0  -                fq_codel           1:3            706          7             0

Attention

The previous command output should include packets for the different HTB classes. If not, obtaining debugging information may prove usuful. This can be achieved by setting the following configuration commands: set traffic control <NAME> type htb match 1 log <PREFIX> or set traffic policy <NAME> rule 1 log prefix <PREFIX>. After generating some traffic, the system journal monitor command can be used to review log messages.