Htb

The following scenario shows how to configure a HTB qdisc.

../../../../../_images/topology8.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=4.16 ms

--- 10.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 4.163/4.163/4.163/0.000 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 49022 connected to 10.0.0.1 port 8080
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  14.1 MBytes   118 Mbits/sec    0    209 KBytes
[  5]   1.00-2.00   sec  11.3 MBytes  94.9 Mbits/sec    0    229 KBytes
[  5]   2.00-3.00   sec  11.2 MBytes  93.8 Mbits/sec    0    229 KBytes
[  5]   3.00-4.00   sec  12.1 MBytes   101 Mbits/sec    0    262 KBytes
[  5]   4.00-5.00   sec  11.2 MBytes  94.4 Mbits/sec    0    262 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-5.00   sec  59.9 MBytes   100 Mbits/sec    0             sender
[  5]   0.00-5.00   sec  58.5 MBytes  98.0 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 45308 connected to 10.0.0.1 port 1234
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  2.80 MBytes  23.5 Mbits/sec    8   70.7 KBytes
[  5]   1.00-2.00   sec  2.24 MBytes  18.8 Mbits/sec    0   70.7 KBytes
[  5]   2.00-3.00   sec  2.24 MBytes  18.8 Mbits/sec    0   70.7 KBytes
[  5]   3.00-4.00   sec  2.24 MBytes  18.8 Mbits/sec    0   70.7 KBytes
[  5]   4.00-5.00   sec  2.24 MBytes  18.8 Mbits/sec    0   70.7 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-5.00   sec  11.7 MBytes  19.7 Mbits/sec    8             sender
[  5]   0.00-5.00   sec  11.3 MBytes  18.9 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      76617542      50653             1
1:1  QDISC            class 1            1:0       64213628      42433             0
1:2  QDISC            class 2            1:0       12403058       8212             0
1:3  QDISC            class 3 (default)  1:0            856          8             0
2:0  -                fq_codel           1:1       64213628      42433             0
3:0  -                fq_codel           1:2       12403058       8212             1
4:0  -                fq_codel           1:3            856          8             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.