LAN monitor
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Speed Test Server Network
yum install epel-release -y
yum install python python-pip -y
pip install --upgrade pip
pip install speedtest-cli
speedtest-cli # speedtest-cli
Retrieving speedtest.net configuration... Retrieving speedtest.net server list... Testing from WorldStream (109.236.84.3)... Selecting best server based on latency... Hosted by SoftLayer Technologies, Inc. (Amsterdam) [33.82 km]: 4.409 ms Testing download speed........................................ Download: 384.73 Mbit/s Testing upload speed.................................................. Upload: 367.74 Mbit/s
iftop – display bandwidth usage on an interface
# iftop -i eno1
Command to check network adapter names in Linux
[root@tswl ~]# lshw -class network -short
H/W path Device Class Description
=============================================================
/0/1/0/3/0 eno1 network Ethernet Connection X722 for 1GbE
/0/1/0/3/0.1 eno2 network Ethernet Connection X722 for 1GbE
/0/1/0/3/0.2 eno3 network Ethernet Connection X722 for 1GbE
/0/1/0/3/0.3 eno4 network Ethernet Connection X722 for 1GbE
/3 dummy0 network Ethernet interface
/4 virbr0-nic network Ethernet interface
/5 virbr0 network Ethernet interface
Ethernet device is up or down
[root@tswl ~]# nmcli device status
DEVICE TYPE STATE CONNECTION
eno1 ethernet connected eno1
eno2 ethernet connected eno2
virbr0 bridge connected virbr0
virbr0-nic tun connected virbr0-nic
eno3 ethernet unavailable --
eno4 ethernet unavailable --
dummy0 dummy unmanaged --
lo loopback unmanaged --
Packet Load Ping
[root@tswl ~]# ping -s 1024 8.8.8.8
change the state of the device to UP or DOWN
ip link set dev {DEVICE} {up|down}
# ip link set dev eth1 down
# ip link set dev eth1 up
change the MTU of the device
ip link set mtu {NUMBER} dev {DEVICE}
# ifconfig eth1 mtu 9000 up
# ip link set mtu 1300 dev eth0
# ip a list eth0
all network interface including received and send packets
# 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 eth0 1500 0 1955323 0 0 0 1563543 0 0 0 BMRU lo 16436 0 27472 0 0 0 27472 0 0 0 LRU
Kernel Interface ERROR
Displaying Kernel IP routing
# netstat -r Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 192.168.0.0 * 255.255.255.0 U 0 0 0 eth0 link-local * 255.255.0.0 U 0 0 0 eth0 default 192.168.0.1 0.0.0.0 UG 0 0 0 eth0
Listing all active listening ports connections with netstat -l.
# netstat -l Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 *:sunrpc *:* LISTEN tcp 0 0 *:58642 *:* LISTEN tcp 0 0 *:ssh *:* LISTEN udp 0 0 *:35036 *:* udp 0 0 *:npmp-local *:* Active UNIX domain sockets (only servers) Proto RefCnt Flags Type State I-Node Path unix 2 [ ACC ] STREAM LISTENING 16972 /tmp/orbit-root/linc-76b-0-6fa08790553d6 unix 2 [ ACC ] STREAM LISTENING 17149 /tmp/orbit-root/linc-794-0-7058d584166d2 unix 2 [ ACC ] STREAM LISTENING 17161 /tmp/orbit-root/linc-792-0-546fe905321cc unix 2 [ ACC ] STREAM LISTENING 15938 /tmp/orbit-root/linc-74b-0-415135cb6aeab
# ip -s link show eno1
2: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000 link/ether 00:1e:4f:c8:43:fc brd ff:ff:ff:ff:ff:ff RX: bytes packets errors dropped overrun mcast 224258568 418718 0 0 0 84376 TX: bytes packets errors dropped carrier collsns 6131373 78152 0 0 0 0
# ip route show
default via 192.168.0.1 dev enp0s25 proto static metric 100 169.254.0.0/16 dev enp0s25 scope link metric 1000 192.168.0.0/24 dev enp0s25 proto kernel scope link src 192.168.0.24 metric 100
[root@mail postfix]# netstat -lnp |grep :25
tcp 0 0 0.0.0.0:25 0.0.0.0:* LISTEN 25792/master
Old vs. new tool
Deprecated Linux command and their replacement cheat sheet:
root@mail ~]# dig +short myip.opendns.com @resolver1.opendns.com
207.76.248.149
[root@mail ~]# curl https://ipinfo.io/ip ; echo
275.229.184.259
[root@mail ~]# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 175.29.184.57 0.0.0.0 UG 100 0 0 em1
175.29.184.0 0.0.0.0 255.255.248.0 U 100 0 0 em1
192.168.9.0 0.0.0.0 255.255.255.0 U 101 0 0 em2
192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0
[root@mail ~]# netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
0.0.0.0 175.29.184.57 0.0.0.0 UG 0 0 0 em1
175.29.184.0 0.0.0.0 255.255.248.0 U 0 0 0 em1
192.168.9.0 0.0.0.0 255.255.255.0 U 0 0 0 em2
192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0
Netstat
netstat -nat [show ports allow]
netstat -ni [ show interface error]
netstat -r
netstat -i [Show the list of network interface]
netstat -ie [Display extended information on the interfaces]
Category
List of Unix and Linux commands
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