What command can you use on a Linux computer to report the IP configuration?
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There are a few commands that should always be in your sysadmin toolbox. Get to know these 7 essential networking commands. Show
Posted: June 2, 2021 |%t min read| by Evans Amoany (Sudoer), Tyler Carrigan (Editorial Team, Red Hat) Image  Image by Hebi B. from Pixabay This article is the first in a series centered around 'crowd sourced' command recommendations. I asked a group of our core contributors what their favorite Linux commands were, and the feedback was overwhelming. We received 46 individual commands, and many of them were underscored by multiple submissions. This series represents the complete list, broken down by category. I have dubbed these first seven commands "Networking commands that everyone should know." Editors Note: Evans Amoany provided the command information and examples. One of our Sudoers and a talented *nix admin. Shoutout to Evans for doing the heavy lifting here. [ You might also enjoy: Linux networking: 13 uses for netstat ] More about cloud services
ipThe The syntax is as follows: ip The OBJECT is the most important part of the synopsis, and the following are supported (some omitted for brevity): address - protocol (IPv4 or IPv6) address on a device.
Here are some common use cases for the To show the IP addresses assigned to an interface on your server: To assign an IP to an interface, for example, enps03: To delete an IP on an interface: Alter the status of the interface by bringing the interface eth0 online: Alter the status of the interface by bringing the interface eth0 offline: Alter the status of the interface by changing the MTU of eth0: Alter the status of the interface by enabling promiscuous mode for eth0: Add a default route (for all addresses) via the local gateway 192.168.1.254 that can be reached on device eth0: Add a route to 192.168.1.0/24 via the gateway at 192.168.1.254: Add a route to 192.168.1.0/24 that can be reached on device eth0: Delete the route for 192.168.1.0/24 via the gateway at 192.168.1.254: Display the route taken for IP 10.10.1.4: ifconfigThe mtrMTR (Matt's traceroute) is a program with a command-line interface that serves as a network diagnostic and troubleshooting tool. This command combines the functionality of the The syntax of the command is as follows: mtr Let's look at some common use cases. The basic Show numeric IP addresses (if you use Show the numeric IP addresses and hostnames, too: Set the number of pings that you want to send: Get a report of the or: Force the use of the TCP instead of the ICMP: Force the use of the UDP instead of the ICMP: Set the maximum amount of hops: Define the packet size: Print to CSV output: Print to XML output: tcpdump
The You can install Before starting any capture, you need to know which interfaces If you want to capture traffic on eth0, you can initiate that with Capture traffic to and from one hostYou can filter out traffic coming from a specific host. For example, to find traffic coming from and going to 8.8.8.8, use the command: For traffic coming from 8.8.8.8, use: For outbound traffic going to 8.8.8.8, use: Capture traffic to and from a networkYou can also capture traffic to and from a specific network using the command below: or: You can also filter based on either source or destination. Based on the source (traffic coming from): Based on the destination (traffic going to): Capture traffic to and from port numbersCapture only DNS port 53 traffic: For a specific host, To capture only HTTPS traffic, To capture all port except port 80 and 25, netstatThe If The primary usage of For advanced usage, expand the Or list the options one by one: To list all ports and connections regardless of their state or protocol, use: List all TCP ports by running: List all UDP ports with: To return a list of only listening ports for all protocols, use: List all listening TCP ports with: Return only listening UDP ports by running: To list UNIX listening ports, use: Display statistics for all ports regardless of the protocol with: List statistics for TCP ports only with: To view the TCP connections with the PID/Program name listed, use: To find a process that is using a particular port number, run: nslookupUse the Consider the following common examples. To find the A record of а domain: To check the NS records of a domain: To find the MX records responsible for the email exchange: To find all of the available DNS records of a domain: To check the use of a specific DNS server (in this case, query using the specific nameserver ns1.nsexample.com): Checking DNS A records to see the IPs of a domain is a common practice, but sometimes you need to verify if an IP address is related to a specific domain. For that purpose, you need a reverse DNS lookup. pingPing is a tool that verifies IP-level connectivity to another TCP/IP computer by sending Internet Control Message Protocol (ICMP) Echo Request messages. The receipt of corresponding Echo Reply messages is displayed, along with round-trip times. Ping is the primary TCP/IP command used to troubleshoot connectivity, reachability, and name resolution. Simple You need to stop the
Also, you will see TTL, which stands for Time To Live. Ping uses a numerical TTL value to attempt to reach a given host computer via the route path. This is also known as the hop limit. Normally, when you run a simple Use option On systems with multiple interfaces, you can specify the interface for the Or use the address on the interface, assuming the interface as 10.233.201.45 as the IP: You can also While pinging a host, you'll find different output from the More Linux resources
Destination Host UnreachableThe possible best reason is there is no route from the local host system and to the destination desired destination host, or a remote router reports that it has no route to the destination host. Request timed outThis result means that no Echo Reply messages were received within the default time of one second or the time that you set while you are pinging that host. This can be due to many different causes; the most common include network congestion, failure of the ARP request, packet filtering/firewall, etc. Unknown host/Ping Request Could Not Find HostMaybe you misspelled the hostname or the host does not exist at all in the network. You must have 0% packet loss for every [ Free cheat sheet: Get a list of Linux utilities and commands for managing servers and networks. ] Looking forwardYou should add these commands and examples into your routines as you configure and troubleshoot your own networks. If you found this type of article helpful, be sure to reach out and let us know. Also, keep an eye out for part two of our community commands list. The next one is 16 general Linux commands that you can't do without.
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Evans AmoanyI work as Unix/Linux Administrator with a passion for high availability systems and clusters. I am a student of performance and optimization of systems and DevOps. I have passion for anything IT related and most importantly automation, high availability, and security. More about me Tyler CarriganTyler is the Sr. Community Manager at Enable Sysadmin, a submarine veteran, and an all-round tech enthusiast! He was first introduced to Red Hat in 2012 by way of a Red Hat Enterprise Linux-based combat system inside the USS Georgia Missile Control Center. More about me Red Hat Summit 2022: On DemandGet the latest on Ansible, Red Hat Enterprise Linux, OpenShift, and more from our virtual event on demand. Register for free Related ContentImage How to schedule jobs using the Linux 'cron' utility Scheduling tasks to run automatically at specific times is essential knowledge for any sysadmin. Posted: December 15, 2022 Author: Alexon Oliveira (Sudoer, Red Hat) Image Learn how Unix influenced Linux, understand Ansible lists and dictionaries, and more tips for sysadmin Which command will display the configured IP address?Using the ipconfig Command
The ipconfig command displays the basic IP addressing information for each network interface on the Windows system. This information includes both the IP address and subnet mask.
Which of the following commands will display the IP address on a Linux system?Using the ifconfig Command
The system will display all network connections – including connected, disconnected, and virtual. Look for the one labeled UP, BROADCAST, RUNNING, MULTICAST to find your IP address.
Which command can we use to get the IP address of a Linux computer quizlet?In Linux, the ipconfig command is used to examine current IP address settings.
What is the Linux macOS equivalent of ipconfig?ifconfig is a command in Unix-like operating systems like Linux, FreeBSD, OpenBSD, macOS for Ethernet network interface configuration. In macOS, the ifconfig command functions as a wrapper to the IPConfiguration agent, and can control the BootP and DHCP clients from the command-line.
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