How to show and clear DHCP bindings on the LAN Huawei VRP (Versatile routing platform) CLI

This is a quick reference guide for clearing DHCP bindings Huawei VRP CLI.

1. display ip pool

The following command will display all the dhcp bindings depending on how it is configured. It will either be interface or pool name. DHCP can either be configured on the interface or globally.

Cisco equivalent “sh ip dhcp binding

display ip pool interface vlanif21 used

display ip pool name testdhcp used

[Huawei]display ip pool ?
   interface     Information of interface pool
   name          Pool name
   vpn-instance  Show IP pool bind the VPN-instance
   |             Matching output

display ip pool interface vlanif21 used  
   Pool-name      : vlanif21
   Pool-No        : 0
   Lease          : 1 Days 0 Hours 0 Minutes
   Domain-name    : -
   DNS-server0    : 8.8.8.8         
   DNS-server1    : 8.8.8.4         
   NBNS-server0   : -               
   Netbios-type   : -               
   Position       : Interface       Status           : Unlocked
   Gateway-0      : 192.168.1.254   
   Mask           : 255.255.255.0
   VPN instance   : --
 
      Start           End     Total  Used  Idle(Expired)  Conflict  Disable
 
  192.168.1.1   192.168.1.254   253     1        252(0)         0        0
 
 Network section : 
 
 Index              IP               MAC      Lease   Status  
 
 252   192.168.1.253    5489-9877-235d      78724   Used

2. Reset ip pool

Cisco equivalent would be “clear ip dhcp binding“.

reset ip pool interface vlanif21 ?
   X.X.X.X   Start IP address
   all       All IP address
   conflict  Conflict IP address
   expired   Expired IP address
   used      Used IP address

or

By pool name

reset ip pool ?
   interface  Interface pool
   name       Pool name




Thank you for reading – please feel free to leave a comment

How to perform throughput testing using iPerf3 on Ubuntu 20.04 CLI

This is a detailed guide on how to perform throughput testing using IPERF on Linux Based Operating Systems.

1. Install iPerf3

You will need to have iPerf3 installed on both endpoints. iPerf3 works using a client and server model.

apt install iperf3

2. iPerf3 Server

Once installed you will need one end point to listen for iPerf traffic. By default this will listen on port 5201.

2.1 iperf3 -s

This command will start the iPerf server

root@FTP:/etc/conf.d# iperf3 -s
-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------

2.2 iperf3 -s -p

This will specify which port to listen on. You will need to ensure that this is specified on both client and server.

root@FTP:/etc/conf.d# iperf3 -s -p 5002
-----------------------------------------------------------
Server listening on 5002
-----------------------------------------------------------

3. iPerf3 Client

Command examples:

Replace 10.0.x.x with the server IP address.

iperf3 -c 10.0.x.x -t 5 -l 1000k
iperf3 -c 10.0.x.x -t 5 -l 1000k -w 2.5m
iperf3 -c 10.0.x.x -t 5 -l 1000k -w 2.5m -P 5
iperf3 -c 10.0.x x -t 60 -l 1000k -w 2.5m -P 5
iperf3 -c 10.0.x.x -t 60 -l 1000k -w 2.5m -P 10 
iperf3 -c 10.0.x.x -t 5 -l 1000k -R
-t, –time nThe time in seconds to transmit for. iPerf normally works by repeatedly sending an array of len bytes for time seconds. Default is 10 seconds.
-l, –length n[KM]The length of buffers to read or write. iPerf works by writing an array of len bytes a number of times. Default is 128 KB for TCP, 8 KB for UDP
-w, –window n[KM]Sets the socket buffer sizes to the specified value. For TCP, this sets the TCP window size. (this gets sent to the server and used on that side too)
-R, –reverseRun in reverse mode (server sends, client receives).

4. Testing using Wondershaper (Traffic Shaper)

You can install wondershaper to shape the client or servers interface bandwidth.

4.1 Install Wondershaper

apt install wondershaper

IMPORTANT: The following installation will create the directory for where the traffic shaping configuration will go.

cd bin
git clone https://github.com/magnific0/wondershaper.git
cd wondershaper
make install

4.2 Edit /etc/conf.d/wondershaper.conf

nano /etc/conf.d/wondershaper.conf

Example configuration:

You will need to specify which interface and what the bandwidth is restricted to in kbps.

[wondershaper]
# Adapter
#
IFACE="eth0"

# Download rate in Kbps
#
DSPEED="10240"

# Upload rate in Kbps
#
USPEED="10240"

4.3 Restart Wondershaper

service wondershaper restart

5. iPerf Before and after Wondershaper.

root@FTP:~# iperf3 -c 10.0.125.14
Connecting to host 10.0.125.14, port 5201
[  4] local 10.0.125.11 port 38860 connected to 10.0.125.14 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec   115 MBytes   968 Mbits/sec    0   3.03 MBytes
[  4]   1.00-2.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   2.00-3.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   3.00-4.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   4.00-5.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   5.00-6.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   6.00-7.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   7.00-8.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   8.00-9.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   9.00-10.00  sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec  1.10 GBytes   942 Mbits/sec    0             sender
[  4]   0.00-10.00  sec  1.09 GBytes   939 Mbits/sec                  receiver

iperf Done.
root@FTP:~# service wondershaper start
root@FTP:~# iperf3 -c 10.0.125.14
Connecting to host 10.0.125.14, port 5201
[  4] local 10.0.125.11 port 38864 connected to 10.0.125.14 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec  1.71 MBytes  14.3 Mbits/sec    0    102 KBytes
[  4]   1.00-2.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   2.00-3.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   3.00-4.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   4.00-5.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   5.00-6.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   6.00-7.00   sec  1.06 MBytes  8.86 Mbits/sec    0    102 KBytes
[  4]   7.00-8.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   8.00-9.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   9.00-10.00  sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec  11.7 MBytes  9.83 Mbits/sec    0             sender
[  4]   0.00-10.00  sec  11.1 MBytes  9.31 Mbits/sec                  receiver

iperf Done.

Thank you for reading and please feel free to leave any feedback.

How to shape traffic using Wondershaper on Ubuntu 20.04 CLI

This is a quick reference guide on how to shape traffic using Wondershaper on Linux Based Operating Systems.

1. Install Wondershaper

apt install wondershaper

IMPORTANT: The following installation will create the directory for where the traffic shaping configuration will go.

cd bin
git clone https://github.com/magnific0/wondershaper.git
cd wondershaper
make install

2. Edit /etc/conf.d/wondershaper.conf

nano /etc/conf.d/wondershaper.conf

Example configuration:

You will need to specify which interface and what the bandwidth is restricted to in kbps.

[wondershaper]
# Adapter
#
IFACE="eth0"

# Download rate in Kbps
#
DSPEED="10240"

# Upload rate in Kbps
#
USPEED="10240"

3. Restart Wondershaper

service wondershaper restart

4. iPerf Before and after Wondershaper.

root@FTP:~# iperf3 -c 10.0.125.14
Connecting to host 10.0.125.14, port 5201
[  4] local 10.0.125.11 port 38860 connected to 10.0.125.14 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec   115 MBytes   968 Mbits/sec    0   3.03 MBytes
[  4]   1.00-2.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   2.00-3.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   3.00-4.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   4.00-5.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   5.00-6.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   6.00-7.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   7.00-8.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   8.00-9.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   9.00-10.00  sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec  1.10 GBytes   942 Mbits/sec    0             sender
[  4]   0.00-10.00  sec  1.09 GBytes   939 Mbits/sec                  receiver

iperf Done.
root@FTP:~# service wondershaper start
root@FTP:~# iperf3 -c 10.0.125.14
Connecting to host 10.0.125.14, port 5201
[  4] local 10.0.125.11 port 38864 connected to 10.0.125.14 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec  1.71 MBytes  14.3 Mbits/sec    0    102 KBytes
[  4]   1.00-2.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   2.00-3.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   3.00-4.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   4.00-5.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   5.00-6.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   6.00-7.00   sec  1.06 MBytes  8.86 Mbits/sec    0    102 KBytes
[  4]   7.00-8.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   8.00-9.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   9.00-10.00  sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec  11.7 MBytes  9.83 Mbits/sec    0             sender
[  4]   0.00-10.00  sec  11.1 MBytes  9.31 Mbits/sec                  receiver

iperf Done.

Thank you for reading and please feel free to leave any feedback.

Getting started with UFW (Uncomplicated Firewall) Ubuntu CLI

This is a quick reference guide about getting started with UFW (Uncomplicated Firewall) Ubuntu CLI

1.Check the status of the firewall

ufw status

root@FTP:~# ufw status
Status: inactive

IMPORTANT! Please see step 2 before enabling the firewall

root@FTP:~# ufw status
Status: active

To                         Action      From
--                         ------      ----
22/tcp                     ALLOW       Anywhere
22/tcp (v6)                ALLOW       Anywhere (v6)

ufw status verbose – gives more information about the firewall status.

root@FTP:~# ufw status verbose
Status: active
Logging: on (low)
Default: deny (incoming), allow (outgoing), disabled (routed)
New profiles: skip

To                         Action      From
--                         ------      ----
22/tcp                     ALLOW IN    Anywhere
22/tcp (v6)                ALLOW IN    Anywhere (v6)


2. Enabling ufw

2.1 CAUTION! Before enabling your firewall make sure that you have added a policy to allow SSH.

root@FTP:/etc/ufw# ufw  allow ssh
Rules updated
Rules updated (v6)

You can check this has been added in the following file: /etc/ufw/user.rules

nano /etc/ufw/user.rules

]

### RULES ###

### tuple ### allow tcp 22 0.0.0.0/0 any 0.0.0.0/0 in
-A ufw-user-input -p tcp --dport 22 -j ACCEPT

2.2 ufw enable

ufw enable

3. Adding ufw rules

3.1 Basic ufw rule examples

The below rules will be from any source to a specific port on the local server.

root@FTP:~# ufw allow http
Rule added
Rule added (v6)
root@FTP:~# ufw allow https
Rule added
Rule added (v6)
root@FTP:~# ufw allow ftp
Rule added
Rule added (v6)
root@FTP:~# ufw allow tftp
Rule added
Rule added (v6)
root@FTP:~# ufw allow snmp
Rule added
Rule added (v6)
root@FTP:~# ufw allow sftp
Rule added
Rule added (v6)
root@FTP:~# ufw allow smtp
Rule added
Rule added (v6)
root@FTP:~# ufw allow 3389
Rule added
Rule added (v6)

3.2 Check ufw rules

root@FTP:~# ufw status
Status: active

To                         Action      From
--                         ------      ----
22/tcp                     ALLOW       Anywhere
80/tcp                     ALLOW       Anywhere
443/tcp                    ALLOW       Anywhere
21/tcp                     ALLOW       Anywhere
69/udp                     ALLOW       Anywhere
161                        ALLOW       Anywhere
115/tcp                    ALLOW       Anywhere
25/tcp                     ALLOW       Anywhere
3389                       ALLOW       Anywhere

3.3 Source and destination specific ufw rules

root@FTP:~# ufw allow from 10.0.125.0/24 to any
Rule added
root@FTP:~# ufw allow from 10.0.130.0/24 to any  port sftp
Rule added
root@FTP:~# ufw status
Anywhere                   ALLOW       10.0.125.0/24
115/tcp                    ALLOW       10.0.130.0/24

4. Delete ufw rules

root@FTP:~# ufw delete allow https
Rule deleted
Rule deleted (v6)
root@FTP:~#

Thank you for reading and please feel free to leave any feedback.

How to shape traffic using Wondershaper on Ubuntu 18.04 CLI

This is a quick reference guide on how to shape traffic using Wondershaper on Linux Based Operating Systems.

1. Install Wondershaper

apt install wondershaper

IMPORTANT: The following installation will create the directory for where the traffic shaping configuration will go.

cd bin
git clone https://github.com/magnific0/wondershaper.git
cd wondershaper
make install

2. Edit /etc/conf.d/wondershaper.conf

nano /etc/conf.d/wondershaper.conf

Example configuration:

You will need to specify which interface and what the bandwidth is restricted to in kbps.

[wondershaper]
# Adapter
#
IFACE="eth0"

# Download rate in Kbps
#
DSPEED="10240"

# Upload rate in Kbps
#
USPEED="10240"

3. Restart Wondershaper

service wondershaper restart

4. iPerf Before and after Wondershaper.

root@FTP:~# iperf3 -c 10.0.125.14
Connecting to host 10.0.125.14, port 5201
[  4] local 10.0.125.11 port 38860 connected to 10.0.125.14 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec   115 MBytes   968 Mbits/sec    0   3.03 MBytes
[  4]   1.00-2.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   2.00-3.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   3.00-4.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   4.00-5.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   5.00-6.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   6.00-7.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   7.00-8.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   8.00-9.00   sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
[  4]   9.00-10.00  sec   112 MBytes   939 Mbits/sec    0   3.03 MBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec  1.10 GBytes   942 Mbits/sec    0             sender
[  4]   0.00-10.00  sec  1.09 GBytes   939 Mbits/sec                  receiver

iperf Done.
root@FTP:~# service wondershaper start
root@FTP:~# iperf3 -c 10.0.125.14
Connecting to host 10.0.125.14, port 5201
[  4] local 10.0.125.11 port 38864 connected to 10.0.125.14 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec  1.71 MBytes  14.3 Mbits/sec    0    102 KBytes
[  4]   1.00-2.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   2.00-3.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   3.00-4.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   4.00-5.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   5.00-6.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   6.00-7.00   sec  1.06 MBytes  8.86 Mbits/sec    0    102 KBytes
[  4]   7.00-8.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   8.00-9.00   sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
[  4]   9.00-10.00  sec  1.12 MBytes  9.38 Mbits/sec    0    102 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec  11.7 MBytes  9.83 Mbits/sec    0             sender
[  4]   0.00-10.00  sec  11.1 MBytes  9.31 Mbits/sec                  receiver

iperf Done.

Thank you for reading and please feel free to leave any feedback.

How to make a shell script executable Linux CLI

This is a quick reference guide on how to make a shell script executable on Linux Based Operating Systems.

1. chmod +x

root@FTP:~# ./shell.sh
-bash: ./shell.sh: Permission denied
root@FTP:~# chmod +x shell.sh
root@FTP:~# ./shell.sh

Thank you for reading and please feel free to leave any feedback.

How to add a user to a group Linux CLI

This is a quick reference guide on how to check your network interfaces on Linux Based Operating Systems.

1. ifconfig -a

root@FTP1:~# addgroup ftpgroup user1
addgroup: The user `ftpgroup' does not exist.
root@FTP1:~# adduser user1 ftpgroup
Adding user `user1' to group `ftpgroup' ...
Adding user user1 to group ftpgroup
Done.
root@FTP1:~# adduser user2 ftpgroup
Adding user `user2' to group `ftpgroup' ...
Adding user user2 to group ftpgroup
Done.

Thank you for reading and please feel free to leave any feedback.

How to change group ownership of a file Linux CLI

This is a quick reference guide on how to change group ownership of a file on Linux Based Operating Systems.

1. Change group ownership of a file using chgrp command

[root@vps1 ~]# chgrp root file1
[root@vps1 ~]# ls -l file1
-rw-r--r-- 1 root root 0 Jun  4 11:06 file1
[root@vps1 ~]# chgrp vpsuser file1
[root@vps1 ~]# ls -l file1
-rw-r--r-- 1 root vpsuser 0 Jun  4 11:06 file1

2. Check the file permission using ls -l

root@vps:~# ls -l file1
-rwxr-x--x 1 root root 0 Jun  3 08:17 file1

A dash (-) indicates that the file is a regular file.

The letter (d) indicates that the file is a directory as per below:

A letter (l) preceding indicates a special file type called a symlink. A symlink is a pointer to another location in the file system.

drwxr-xr-x 3 root root       4096 Oct 18  2018 ufw

The first three letters above refer to the permission of the user so in this case rwx, so read, write, and execute.

The next three letters is for group r-x, so read and execute, but not write as indicated by the dash.

The next three letters is for other r-x, so read and execute, but not write as indicated by the dash. (so the same as group in this example)

The number 3 in this example after the permissions indicates the number of files or sub-directories contained within this particular directory.

The first name after the number (directory and file number) in the example below is the user or file owner. “vpsuser”

The second name refers to the files group. “group1”

-rwxr-x--x 1 vpsuser group1 0 Jun  3 08:17 file1
root@vps:~#

The remainder of the file details are the size of the file, the date and time that the file was created or last modified, and the file name.

Thank you for reading and please feel free to leave any feedback.

How to show interface statistics using netstat -i command Linux CLI

This is a quick reference on how to show interface statistics using the netstat -i command on Linux Based Operating Systems.

1. netstat -i

root@GNS3-Server:~# netstat -i
Kernel Interface table
Iface   MTU Met   RX-OK RX-ERR RX-DRP RX-OVR    TX-OK TX-ERR TX-DRP TX-OVR Flg
docker0    1500 0         0      0      0 0             0      0      0      0 BMU
eth0       1500 0       572      0      0 0           359      0      0      0 BMRU
eth1       1500 0        43      0      0 0            37      0      0      0 BMRU
lo        65536 0      3172      0      0 0          3172      0      0      0 LRU
tun1194    1500 0         0      0      0 0             0      0      0      0 MOPRU
virbr0     1500 0         0      0      0 0             0      0      0      0 BMU
root@GNS3-Server:~#

Thank you for reading and please feel free to leave any feedback.

How to show established tcp connections using the netstat command Linux (Ubuntu | Debian | Centos) CLI

This is a quick reference on how to show established tcp connections using the netstat command on Linux Based Operating Systems.

1. netstat

root@GNS3-Server:~# netstat
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0      0 172.16.253.1:3080       172.16.253.1:43486      ESTABLISHED
tcp        0      0 172.16.253.1:43486      172.16.253.1:3080       ESTABLISHED
tcp        0      0 10.0.125.10:ssh         90.240.10.190:59675     ESTABLISHED

Thank you for reading and please feel free to leave any feedback.