Administering Oracle Linux 7: Part 2 — Network Management
This article is Part 2 of a series that explains how to administer Oracle Linux 7. This article focuses on how to configure and administer the network configuration in Oracle Linux 7.
Introduction to Network Management
Oracle Linux 7 has deeply changed its framework for the configuration and management of the network, so for anyone who works and configures common services such as web services, e-mail services, and LDAP services, this article shows the correct step-by-step procedures for how to administer the network.
From previous versions, there are basic commands that are used to monitor and verify the network configuration, and these commands can still be useful while administering and maintaining an Oracle Linux 7 environment. For example, to check the link state and IP address bound to each network interface, execute the following commands:
[root@oel73 ~]# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000
link/ether 00:0c:29:c4:c1:47 brd ff:ff:ff:ff:ff:ff
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT
link/ether 52:54:00:fc:40:f7 brd ff:ff:ff:ff:ff:ff
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN mode DEFAULT qlen 500
link/ether 52:54:00:fc:40:f7 brd ff:ff:ff:ff:ff:ff
[root@oel73 ~]# ip addr show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:c4:c1:47 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.112/24 brd 192.168.1.255 scope global ens33
inet6 fe80::20c:29ff:fec4:c147/64 scope link
valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN
link/ether 52:54:00:fc:40:f7 brd ff:ff:ff:ff:ff:ff
inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
inet6 fe80::5054:ff:fefc:40f7/64 scope link
valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN qlen 500
link/ether 52:54:00:fc:40:f7 brd ff:ff:ff:ff:ff:ffAs you can see in the output above, the main interface is ens33 (Oracle Linux 7 is running over VMware Workstation), it is connected to the network, and its IP address is 192.168.1.112. Additionally, the IP route table on the system is shown by running the following command:
[root@oel73 ~]# ip route show
default via 192.168.1.1 dev ens33 proto static metric 1024
192.168.1.0/24 dev ens33 proto kernel scope link src 192.168.1.112
192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1Indeed, there are two routes associated to ens33 network interface and one of them is the default gateway. The next step is to learn how to configure the network interfaces on Oracle Linux 7.
Gathering Information About the Network
Oracle Linux 7 has a very important daemon named Network Manager that monitors and manages all network settings. In the Network Manager context, a network interface is a device and a connection is a configuration used by this device. You can create multiple connections for a device, but only one of them can be active. Moreover, the configuration files from Network Manager are saved in the /etc/sysconfig/network-scripts directory, as shown below:
[root@oel73 ~]# cd /etc/sysconfig/network-scripts/
[root@oel73 network-scripts]# ls -al
-rw-r--r--. 1 root root 298 Apr 4 23:06 ifcfg-Auto_Ethernet-1
-rw-r--r--. 1 root root 254 Apr 2 2014 ifcfg-lo
lrwxrwxrwx. 1 root root 24 Feb 11 01:56 ifdown -> ../../../usr/sbin/ifdown
-rwxr-xr-x. 1 root root 627 Apr 2 2014 ifdown-bnep
-rwxr-xr-x. 1 root root 5553 Apr 2 2014 ifdown-eth
-rwxr-xr-x. 1 root root 781 Apr 2 2014 ifdown-ippp
-rwxr-xr-x. 1 root root 4141 Apr 2 2014 ifdown-ipv6
lrwxrwxrwx. 1 root root 11 Feb 11 01:56 ifdown-isdn -> ifdown-ippp
-rwxr-xr-x. 1 root root 1642 Apr 2 2014 ifdown-post
-rwxr-xr-x. 1 root root 1068 Apr 2 2014 ifdown-ppp
-rwxr-xr-x. 1 root root 837 Apr 2 2014 ifdown-routes
-rwxr-xr-x. 1 root root 1444 Apr 2 2014 ifdown-sit…
To verify all connections and the active ones, execute the following commands:
[root@oel73 ~]# nmcli con show
NAME UUID TYPE DEVICE
Auto Ethernet 42cc5b4c-b574-41dc-9d3f-ddd6ec0e38d3 802-3-ethernet ens33
virbr0-nic 7d787f69-5536-4a95-8348-6bff621e1b05 generic virbr0-nic
virbr0 b70e08f1-1a85-449d-be7c-9a68d5942c63 bridge virbr0
[root@oel73 ~]# nmcli con show --active
NAME UUID TYPE DEVICE
Auto Ethernet 42cc5b4c-b574-41dc-9d3f-ddd6ec0e38d3 802-3-ethernet ens33
virbr0-nic 7d787f69-5536-4a95-8348-6bff621e1b05 generic virbr0-nic
virbr0 b70e08f1-1a85-449d-be7c-9a68d5942c63 bridge virbr0To collect further details about a specific connection, execute the following:
[root@oel73 ~]# nmcli con show "Auto Ethernet"
connection.id: Auto Ethernet
connection.uuid: 42cc5b4c-b574-41dc-9d3f-ddd6ec0e38d3
connection.interface-name: --
connection.type: 802-3-ethernet
connection.autoconnect: yes
connection.timestamp: 1428200895
connection.read-only: no
connection.permissions:
connection.zone: --
connection.master: --
connection.slave-type: --
connection.secondaries:
connection.gateway-ping-timeout: 0
802-3-ethernet.port: --
802-3-ethernet.speed: 0
802-3-ethernet.duplex: --
802-3-ethernet.auto-negotiate: yes
802-3-ethernet.mac-address: 00:0C:29:C4:C1:47
802-3-ethernet.cloned-mac-address: --
802-3-ethernet.mac-address-blacklist:
802-3-ethernet.mtu: auto
802-3-ethernet.s390-subchannels:
...The Universally Unique Identifier (UUID) of the connection also could be used, as shown below:
[root@oel73 ~]# nmcli con show 42cc5b4c-b574-41dc-9d3f-ddd6ec0e38d3
connection.id: Auto Ethernet
connection.uuid: 42cc5b4c-b574-41dc-9d3f-ddd6ec0e38d3
connection.interface-name: --
connection.type: 802-3-ethernet
...Instead of collecting details about a connection, we could gather essential information about a specific device (ens33) by running the following command:
[root@oel73 ~]# nmcli dev show ens33
GENERAL.DEVICE: ens33
GENERAL.TYPE: ethernet
GENERAL.HWADDR: 00:0C:29:C4:C1:47
GENERAL.MTU: 1500
GENERAL.STATE: 100 (connected)
GENERAL.CONNECTION: Auto Ethernet
GENERAL.CON-PATH: /org/freedesktop/NetworkManager/ActiveConnection/0
WIRED-PROPERTIES.CARRIER: on
IP4.ADDRESS[1]: ip = 192.168.1.112/24, gw = 192.168.1.1
IP4.DNS[1]: 192.168.1.1
IP4.DOMAIN[1]: example.com
IP6.ADDRESS[1]: ip = fe80::20c:29ff:fec4:c147/64, gw = ::To show the general status of each interface, execute the following:
[root@oel73 ~]# nmcli dev status
DEVICE TYPE STATE CONNECTION
ens33 ethernet connected Auto Ethernet
virbr0-nic tap connected virbr0-nic
virbr0 bridge connecting (getting IP configuration) virbr0
lo loopback unmanaged --Configuring a Network Interface
The network configuration procedure has changed a lot since Oracle Linux 6. It now can be done in an easy way using either the command line (nmcli tool) or a GUI tool (not discussed in this article).
To configure a network interface, we have to create a connection (for example, myconnection) and associate this new connection to a device (ens33). Furthermore, the IP configuration can be bound through either the DHCP service or a static IP address. In this example, the device (ens33) will be associated with an IP address by using the DHCP service. Thus, to perform both tasks, execute the following commands:
[root@oel73 ~]# nmcli con add con-name "myconnection" type ethernet ifname ens33
Connection 'myconnection' (a4f95890-34b4-457c-bedd-567b9560ec36) successfully added.
[root@oel73 ~]# nmcli con show
NAME UUID TYPE DEVICE
myconnection a4f95890-34b4-457c-bedd-567b9560ec36 802-3-ethernet --
Auto Ethernet 42cc5b4c-b574-41dc-9d3f-ddd6ec0e38d3 802-3-ethernet ens33
virbr0-nic 7d787f69-5536-4a95-8348-6bff621e1b05 generic virbr0-nic
virbr0 b70e08f1-1a85-449d-be7c-9a68d5942c63 bridge virbr0Because the chosen method to configure an IP address was by using DHCP service, the task is finished. To make myconnection active, execute the following:
[root@oel73 ~]# nmcli con up "myconnection"
Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/3)
[root@oel73 ~]# nmcli con show --active
NAME UUID TYPE DEVICE
myconnection a4f95890-34b4-457c-bedd-567b9560ec36 802-3-ethernet ens33
virbr0-nic d787f69-5536-4a95-8348-6bff621e1b05 generic virbr0-nic
virbr0 b70e08f1-1a85-449d-be7c-9a68d5942c63 bridge virbr0To verify the acquired configuration, run the following:
[root@oel73 ~]# nmcli con show myconnection | grep 'DHCP4|IP4'
IP4.ADDRESS[1]: ip = 192.168.1.112/24, gw = 192.168.1.1
IP4.DNS[1]: 192.168.1.1
IP4.DOMAIN[1]: example.com
DHCP4.OPTION[1]: requested_domain_search = 1
DHCP4.OPTION[2]: requested_nis_domain = 1
DHCP4.OPTION[3]: requested_time_offset = 1
DHCP4.OPTION[4]: requested_broadcast_address = 1
DHCP4.OPTION[5]: requested_rfc3442_classless_static_routes = 1
DHCP4.OPTION[6]: requested_classless_static_routes = 1
DHCP4.OPTION[7]: requested_domain_name = 1
DHCP4.OPTION[8]: expiry = 1428293140
DHCP4.OPTION[9]: domain_name = example.com
DHCP4.OPTION[10]: next_server = 0.0.0.0
DHCP4.OPTION[11]: broadcast_address = 192.168.1.255
DHCP4.OPTION[12]: dhcp_message_type = 5
DHCP4.OPTION[13]: requested_subnet_mask = 1
DHCP4.OPTION[14]: dhcp_lease_time = 86400
DHCP4.OPTION[15]: routers = 192.168.1.1
DHCP4.OPTION[16]: ip_address = 192.168.1.112
DHCP4.OPTION[17]: requested_static_routes = 1
DHCP4.OPTION[18]: requested_interface_mtu = 1
DHCP4.OPTION[19]: requested_nis_servers = 1
DHCP4.OPTION[20]: requested_wpad = 1
DHCP4.OPTION[21]: requested_ntp_servers = 1
DHCP4.OPTION[22]: requested_domain_name_servers = 1
DHCP4.OPTION[23]: domain_name_servers = 192.168.1.1
DHCP4.OPTION[24]: requested_ms_classless_static_routes = 1
DHCP4.OPTION[25]: requested_routers = 1
DHCP4.OPTION[26]: subnet_mask = 255.255.255.0
DHCP4.OPTION[27]: network_number = 192.168.1.0
DHCP4.OPTION[28]: requested_host_name = 1
DHCP4.OPTION[29]: dhcp_server_identifier = 192.168.1.1Let’s create a new connection (mystatic), but this time using a static IP address configuration, as shown below:
[root@oel73 ~]# nmcli con add con-name "mystatic" ifname ens33 autoconnect yes type ethernet ip4 192.168.1.98/24 gw4 192.168.1.1
Connection 'mystatic' (26aa478c-90e6-4172-9e17-07004e61478d) successfully added.Some of the options deserve a quick explanation:
- con-name specifies the name of the connection (mystatic)
- if-name specifies the name of the device (ens33)
- autoconnect yes specifies that this connection should be made active at boot
- type ethernet specifies the OSI layer 2
- ip4192.168.1.98/24 specifies an IP address version 4 address and mask
- gw4192.168.1.1specifies the default router
To list the connections, execute the following:
[root@oel73 ~]# nmcli con show
NAME UUID TYPE DEVICE
myconnection a4f95890-34b4-457c-bedd-567b9560ec36 802-3-ethernet ens33
Auto Ethernet 42cc5b4c-b574-41dc-9d3f-ddd6ec0e38d3 802-3-ethernet --
virbr0-nic 7d787f69-5536-4a95-8348-6bff621e1b05 generic virbr0-nic
virbr0 b70e08f1-1a85-449d-be7c-9a68d5942c63 bridge virbr0
mystatic 26aa478c-90e6-4172-9e17-07004e61478d 802-3-ethernet --To make mystatic active, execute these commands:
[root@oel73 ~]# nmcli con show --active
NAME UUID TYPE DEVICE
myconnection a4f95890-34b4-457c-bedd-567b9560ec36 802-3-ethernet ens33
virbr0-nic 7d787f69-5536-4a95-8348-6bff621e1b05 generic virbr0-nic
virbr0 b70e08f1-1a85-449d-be7c-9a68d5942c63 bridge virbr0
[root@oel73 ~]# nmcli con up "mystatic"
Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/5)
[root@oel73 ~]# nmcli con show --active
NAME UUID TYPE DEVICE
virbr0-nic 7d787f69-5536-4a95-8348-6bff621e1b05 generic virbr0-nic
virbr0 b70e08f1-1a85-449d-be7c-9a68d5942c63 bridge virbr0
mystatic 26aa478c-90e6-4172-9e17-07004e61478d 802-3-ethernet ens33
[root@oel73 ~]# ip addr show ens33
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:c4:c1:47 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.98/24 brd 192.168.1.255 scope global ens33
inet6 fe80::20c:29ff:fec4:c147/64 scope link
valid_lft forever preferred_lft foreverThe mystatic connection has the following attributes:
[root@oel73 ~]# nmcli con show "mystatic" | grep ipv4
ipv4.method: manual
ipv4.dns:
ipv4.dns-search:
ipv4.addresses: { ip = 192.168.1.98/24, gw = 192.168.1.1 }
ipv4.routes:
ipv4.ignore-auto-routes: no
ipv4.ignore-auto-dns: no
ipv4.dhcp-client-id: --
ipv4.dhcp-send-hostname: yes
ipv4.dhcp-hostname: --
ipv4.never-default: no
ipv4.may-fail: yesAs we can see, there isn’t any DNS configuration. Thus, to configure the DNS (primary and second DNS servers), execute the following:
[root@oel73 ~]# nmcli con mod "mystatic" ipv4.dns 8.8.8.8
[root@oel73 ~]# nmcli con mod "mystatic" +ipv4.dns 8.8.4.4To change the domain search name, run this command:
[root@oel73 ~]# nmcli con mod "mystatic" ipv4.dns-search example.comThe new settings become active only after restarting the connection, as shown below:
[root@oel73 ~]# nmcli con down "mystatic"
[root@oel73 ~]# nmcli con up "mystatic"Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/9)
To check the new DNS settings, run the following:
[root@oel73 ~]# nmcli con show "mystatic" | grep ipv4.dns
ipv4.dns: 8.8.8.8, 8.8.4.4
ipv4.dns-search: example.comIf we need to change the IP address of the mystatic connection (keeping the default gateway), then we have to execute the following commands:
[root@oel73 ~]# nmcli con mod "mystatic" ipv4.addresses "192.168.1.86/24 192.168.1.1"
[root@oel73 ~]# nmcli con down "mystatic"
[root@oel73 ~]# nmcli con up "mystatic"
Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/13)
[root@oel73 ~]# nmcli con show "mystatic" | grep -i ip4.address
IP4.ADDRESS[1]: ip = 192.168.1.86/24, gw = 192.168.1.1When the mystatic connection was created, the autoconnect attribute was set to yes. The problem is that the myconnection connection also has the autoconnect attribute set to yes. Therefore, we have to change one of them to no and this change can be done by executing the following commands:
[root@oel73 ~]# nmcli con mod "myconnection" connection.autoconnect no
[root@oel73 ~]# nmcli con show "myconnection" | grep -i autoconnect
connection.autoconnect: noIf we wish to delete a connection, run the following:
[root@oel73 ~]# nmcli con delete "Auto Ethernet"To make sure that everything is working, we can reboot the Oracle Linux 7 system:
[root@oel73 ~]# systemctl reboot
[root@oel73 ~]# ip addr show ens33
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:c4:c1:47 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.86/24 brd 192.168.1.255 scope global ens33
inet6 fe80::20c:29ff:fec4:c147/64 scope link
valid_lft forever preferred_lft foreverTo verify network access from the current system to Oracle’s website, we can run the traceroutecommand using the –I option (which uses ICMP rather than UDP), as shown below:
[root@oel73 ~]# traceroute -I www.oracle.com
traceroute to www.oracle.com (23.216.182.140), 30 hops max, 60 byte packets
1 192.168.1.1 (192.168.1.1) 0.449 ms 0.541 ms 0.470 ms
2 192.168.0.1 (192.168.0.1) 1.404 ms 2.343 ms 2.878 ms
3 * * *
4 c906009d.virtua.com.br (201.6.0.157) 60.403 ms 60.372 ms 60.313 ms
5 c9062985.virtua.com.br (201.6.41.133) 61.191 ms 62.129 ms 62.076 ms
6 embratel-T0-0-1-1-uacc03.spomb.embratel.net.br (201.64.46.13) 61.012 ms 16.462 ms 17.325 ms
7 200.244.212.105 (200.244.212.105) 25.647 ms 200.244.212.77 (200.244.212.77) 31.840 ms 200.244.212.75 (200.244.212.75) 30.765 ms
8 200.244.212.71 (200.244.212.71) 38.244 ms ebt-B10-tcore01.spo.embratel.net.br (200.230.0.2) 36.754 ms 36.295 ms
9 200.230.231.89 (200.230.231.89) 35.309 ms 35.749 ms ebt-T0-2-5-0-tacc02.spo.embratel.net.br (200.230.158.69) 36.877 ms
10 189.2.4.130 (189.2.4.130) 33.618 ms 49.345 ms 49.257 ms
11 a23-216-182-140.deploy.static.akamaitechnologies.com (23.216.182.140) 47.033 ms 47.936 ms 56.556 msSometimes we could face problems when using the conventional traceroute command with the ICMP protocol. To circumvent this problem, we should use UDP packets, but they are usually blocked and, even when firewalls allow UDP traffic, the traceroute command fails.
The reason for the traceroute command failing when the target website allows UDP packets is that even we are able to set up the starting port by using the –p option, the destination port is increased by one for each interaction, and firewalls usually block lots of ports that are essential for a website to work. A long time ago, Michael Schiffman created a patched traceroute (version 1.4a13), which can be downloaded here: http://packetfactory.openwall.net/projects/firewalk/dist/traceroute/traceroute-1.4a12-packetfatory.tar.gz. (The correct file is downloaded even though the URL contains “1.4a12.”). It has the –S option, which forces the destination port number to a fixed value. This patched version of traceroute is used by many security professionals (including myself). To compile it, run these commands:
[root@oel73 ~]# tar zxvf traceroute-1.4a12-packetfatory.tar.gz
[root@oel73 ~]# cd traceroute-1.4a13/
[root@oel73 traceroute-1.4a13]# cp -r linux-include/ /usr/include/
[root@oel73 traceroute-1.4a13]# cd /usr/include/netinet/
[root@oel73 netinet]# cp * ../linux-include/netinet/
cp: overwrite ‘../linux-include/netinet/in_systm.h’? n
cp: overwrite ‘../linux-include/netinet/ip.h’? n
cp: overwrite ‘../linux-include/netinet/ip_icmp.h’? n
cp: overwrite ‘../linux-include/netinet/udp.h’? nEdit the traceroute.c file and change the following lines from:
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/ip_icmp.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>To this:
#include <linux-include/netinet/in_systm.h>
#include <linux-include/netinet/in.h>
#include <linux-include/netinet/ip.h>
#include <linux-include/netinet/ip_var.h>
#include <linux-include/netinet/ip_icmp.h>
#include <linux-include/netinet/udp.h>
#include <linux-include/netinet/udp_var.h>Run the configuration script:
[root@oel73 traceroute-1.4a13]# ./configure
[root@oel73 traceroute-1.4a13]# makeOnce more, most firewalls don’t allow UDP packets coming from the internet. However, in case we find one that allows them, fixing the destination port to 53 (usually opened and used by the DNS service) will increase our chances. The suggested syntax to perform this task would be the following:
[root@oel73 traceroute-1.4a13]# ./traceroute -S -p53 192.168.1.115This question about security is out of scope for this article, but it is good to dedicate some time to study it.
Checking Network Files and Changing a Host Name
Although manually editing network files has been a frequently used approach by administrators, the nmclicommand offers a simple and robust interface to do this task without running any risks.
Anyway, it’s possible to change the network configuration by editing the network files. For example, we can verify our mystatic connection by executing the following commands:
[root@oel73 ~]# cd /etc/sysconfig/network-scripts/
[root@oel73 network-scripts]# more ifcfg-mystatic
TYPE=Ethernet
BOOTPROTO=none
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
NAME=mystatic
UUID=26aa478c-90e6-4172-9e17-07004e61478d
DEVICE=ens33
ONBOOT=yes
DNS1=8.8.8.8
DNS2=8.8.4.4
DOMAIN=example.com
IPADDR=192.168.1.86
PREFIX=24
GATEWAY=192.168.1.1
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yesIf we change this file or any other network configuration file by using a text editor, we have to execute the following commands for the changes to take effect:
[root@oel73 network-scripts]# nmcli con reload
[root@oel73 network-scripts]# nmcli con down "mystatic"
[root@oel73 network-scripts]# nmcli con up "mystatic"Finally, to change the system’s host name, execute these commands:
[root@oel73 ~]# hostname
oel73.example.com
[root@oel73 ~]# hostnamectl set-hostname myoracle.example.com
[root@oel73 ~]# hostname
myoracle.example.com
[root@oel73 ~]# more /etc/hostname
myoracle.example.comEdit the /etc/hosts file to reflect the new host name and to make the name resolution work:
[root@oel73 ~]# more /etc/hosts | grep myoracle
192.168.1.86myoracle.example.com myoracleTo see the summarized system information, execute the following:
[root@oel73 ~]# hostnamectl status
Static hostname: myoracle.example.com
Icon name: computer
Chassis: n/a
Machine ID: 4b2c3503d92b46d39c4f71a40716fee3
Boot ID: 10a9f862daab4319a682287d730211bf
Virtualization: vmware
Operating System: Oracle Linux Server 7.0
CPE OS Name: cpe:/o:oracle:oracle_linux:7.0:GA:server
Kernel: Linux 3.8.13-55.1.5.el7uek.x86_64
Architecture: x86_64As we saw, network management on Oracle Linux 7 is a simple and straightforward task that any administrator will be involved with on a regular basis.
See Also
Here are some links to other things I’ve written:
- Alexandre Borges on Twitter
- Alexandre Borges’ personal blog
- “Exploring Installation Options and User Roles in Oracle Solaris 11“
- “Exploring Networking, Services, and the New Image Packaging System in Oracle Solaris 11“
- ZFS Series https://community.oracle.com/docs/DOC-914874
