=====Manage Networking====

Service configuration files are stored in the /etc/NetworkManager/system-connections/ directory.
====nmcli====
a staple for network management

Here are some nmcli command options and what they do
^  option  ^ function  |
^  nmcli dev status  | displays status of all network devices |
^  con show  | display all connections use <nowiki> --active</nowiki> to show active ones  or just a connection name for more details |
^  dev disconnect  | disconnects the specified network device|
^  con add con-name  | adds a network connection. need to specify a lot more stuff |
^  connection modify  | to make changes to the config of a connection |
^  con reload  | to reload a connection |
^  con up name  | Activate the connection name|
^  dev dis dev  | Disconnect the interface, which also deactivates the current connection |

example of one is
<code>nmcli con add con-name eno3 type ethernet ifname eno3 ipv4.method manual ipv4.addresses 192.168.0.5/24 ipv4.gateway 192.168.0.254</code>

<code> nmcli con mod static-ens3 ipv4.addresses 192.0.2.2/24 ipv4.gateway 192.0.2.254 connection.autoconnect yes </code>

====ip====
to get details about the networking config of a device use
<code>ip addr show dev eth0 

[user@host ~]$ ip addr show dev eth0
3: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 52:54:00:01:fa:0a brd ff:ff:ff:ff:ff:ff
    inet 10.42.0.1/16 brd 10.42.255.255 scope global noprefixroute eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::7418:cf98:c742:3681/64 scope link noprefixroute
       valid_lft forever preferred_lft forever</code>
       
TO just get the IP address use <code> --br</code>
here is for one device 
<code>
[user@host ~]$ ip -br addr show dev eth0
eth0          UP          10.42.0.1/16 fe80::7418:cf98:c742:3681/64</code>

and here it is for all nics
<code>
[u-ansible@dubrhsatserver62 plays]$ ip -br addr show
lo               UNKNOWN        127.0.0.1/8
ens192           UP             10.5.5.70/24
virbr0           DOWN           192.168.122.1/24
</code>

use **-s** option to show the statistic for interface
 <code>
[student@servera ~]$ ip -s link show enX
2: enX: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000
    link/ether 52:54:00:00:fa:0a brd ff:ff:ff:ff:ff:ff
    RX: bytes  packets  errors  dropped overrun mcast
    89014225   168251   0       154418  0       0
    TX: bytes  packets  errors  dropped carrier collsns
    608808     6090     0       0       0       0 </code>

====Network  troubleshooting tools====

^  command  ^  usage  ^
^  mtr  | similar to tracepath but does notinuos checking |
^  ss  | checkes the sockets best option to use with it is **-plunt** allows you to see ports opened per ip |
^  nmap  | use option **-sS** gives you what ports are open |
^  ip -s link show interace  | Displays statistics for the interface |