> ## Content Index > Fetch the complete content index at: https://devopscube.com/llms.txt > Use this file to discover other available public pages before exploring further. # 18 Best Linux Networking and Troubleshooting Commands for Beginners - URL: https://devopscube.com/list-linux-networking-troubleshooting-and-commands-beginners/ - Published: 2025-10-13T01:19:00.000Z - Updated: 2025-10-13T04:37:52.000Z - Author: devopscube - Tags: LINUX, Linux networking, #Migrated-1741795015845, #wp, #wp-post, #Import 2025-03-12 15:57, #blog, #syntax-highlight Network configuration, diagnostics and general **Linux troubleshooting** areessential parts of System administration. Even for a developer who works with Linux systems, knowledge about **Linux networking commands** is an added advantage. Specifically, if you want to [become a DevOps engineer](https://devopscube.com/become-devops-engineer/) or be part of SRE, it is essential to know all the **Linux troubleshooting commands** as they will be part of your day-to-day activities. Also, in real-world production systems, knowing how to diagnose DNS failures, slow connections, or blocked ports is very important. This post will cover the important **linux networking and troubleshooting commands** that are natively available in Linux systems. ## What are the best Linux Networking and Troubleshooting Commands? Following is the list of natively available troubleshooting commands. | **Command** | **Description** | | -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **hostname** | To check and set the hostname of the server. | | **host** | To get host DNS details | | **ping** | Checks if the remote server is reachable using [ICMP protocol](https://en.wikipedia.org/wiki/Internet%5FControl%5FMessage%5FProtocol?ref=devopscube.com). It also shows the round trip time of packets. | | **curl** | A cross-platform utility that is used to transfer data. It can be used for troubleshooting several network issues. | | **wget** | Utility to download files. Can be used for troubleshooting proxy connections and connectivity. | | **ip** | A replacement for ifconfig. Can be used to configure and retrieve information about systems network interfaces | | **arp** | Utility to view and manage [arp cache](https://en.wikipedia.org/wiki/ARP%5Fcache?ref=devopscube.com). | | **ss/netstat** | Primarily used to check the connections and PID on ports and Unix sockets. | | **traceroute** | This utility uses the ICMP protocol and finds the hops involved in reading the destination server. It also shows the time it takes between hops. | | **mtr** | mtr is a mix of ping and traceroute. It also provides additional information like intermediate hosts and responsiveness. | | **dig** | Helps you get the DNS records associated with a domain name. | | **nslookup** | Command similar to dig. | | **nc** | utility to debug TCP/UDP sockets. | | **telnet** | It can be used to test remote connectivity on ports | | **route** | Helps you get all the route table information | | **tcpdump** | This utility helps you to capture network packets and analyze them for network issues. | | **lsof** | list all the open files and the process information that opened it | | **resolvectl** | Checks DNS configuration and status | Let's understand each command and see how we can use it to troubleshoot Linux. 📌 ****Important Note:** Every command/utility mentioned in this post has many options and flags. Every command has a man page and you can use it to identify the flags and options that are required for your use case. For example, for `ip` command, you can just type it `man ip` in the terminal to get all the details about that command. ### 1\. hostname Hostname command is used to view the hostname of the machine and to set the hostname. ```bash hostname ``` You can use the hostname command to set a new hostname for the machine. For example, ```bash sudo hostname temp.com ``` If you set the hostname using "`hostname`" command, when you restart the machine, the hostname will change to the name specified in the hostname file ( eg: /etc/hostname). So if you want to change the hostname permanently, you can use the `/etc/hosts` file or relevant hostname file present on the server. 1. For ubuntu machines, you can change it in the **`/etc/hostname`** file. 2. For RHEL, CentOS and Fedora you can change it in the **`/etc/sysconfig/network`** file. ### 2\. host Host command is for the reverse lookup of IP or a DNS name. For example, If you want to find a DNS attached with an IP you can use the host commands as follows. ```bash host 8.8.8.8 ``` You can also do the reverse to find the IP address associated with the domain name. For example, ```bash host devopscube.com ``` ### 3\. ping The ping networking utility is used to check if the remote server is reachable or not. It is primarily used for checking the connectivity and troubleshooting the network. It provides the following details. 1. Bytes sent and received 2. Packets sent, received, and lost 3. Approximate round-trip time (in milliseconds) Ping command has the following syntax. ```bash ping ``` For example, ```bash ping devopscube.com ``` To ping IP address ```bash ping 8.8.8.8 ``` If you want to limit the ping output without using ctrl+c, then you can use the "-c" flag with a number as shown below. ```bash ping -c 1 devopscube.com ``` ### 4\. curl Curl utility is primarily used to transfer data from or to a server. However, you can use it for network troubleshooting. For network troubleshooting, `curl` supports protocols such as `DICT`, `FILE`, `FTP`, `FTPS`, `GOPHER`, `HTTP`, `HTTPS`, `IMAP`, `IMAPS`, `LDAP`, `LDAPS`, `MQTT`, `POP3`, `POP3S`, `RTMP`, `RTMPS`, `RTSP`, `SCP`, `SFTP`, `SMB`, `SMBS`, `SMTP`, `SMTPS`, `TELNET` and `TFTP` For example, `curl` can check connectivity on port 22 using telnet. ```bash curl -v telnet://192.168.33.10:22 ``` You can check the FTP connectivity using curl. ```bash curl ftp://ftptest.net ``` You can troubleshoot web server connectivity as well. ```bash curl http://devopscube.com -I ``` ### 5\. wget The `wget` command is primarily used to fetch web pages. You can use `wget` to troubleshoot network issues as well. For example, you can troubleshoot [proxy server](https://devopscube.com/setup-and-configure-proxy-server/) connections using wget. ```bash wget -e use_proxy=yes http_proxy= http://externalsite.com ``` You can check if a website is up by fetching the files. ```bash wget www.google.com ``` ### 6\. ip (ifconfig) **`ip`** command is used to display and manipulate routes and network interfaces. **ip** command is the newer version of **`ifconfig`.** ifconfig works in all the systems, but it is better to use ip command instead of ifconfig. Let's have a look at a few examples of `ip` command. #### Display network devices and configuration ```bash ip addr ``` You can use this command with pipes and grep to get more granular output like the IP address of the eth0 interface. It is very useful when you work on [automation tools](https://devopscube.com/devops-tools-for-infrastructure-automation/) that require IP to be fetched dynamically. The following command gets the IP address of `eth0` network interface. ```bash ip a | grep eth0 | grep "inet" | awk -F" " '{print $2}' ``` Get details of a specific interface ```bash ip a show eth0 ``` You can list the routing tables. ```bash ip route ip route list ``` ### 7\. arp ARP (**Address Resolution Protocol**) shows the cache table of local networks' IP addresses and MAC addresses that the system interacted with. ```bash arp ``` Example output, ```bash vagrant@dcubelab:~$ arp Address HWtype HWaddress Flags Mask Iface 10.0.2.3 ether 52:54:00:12:35:03 C eth0 192.168.33.1 ether 0a:00:27:00:00:00 C eth1 10.0.2.2 ether 52:54:00:12:35:02 C eth0 ``` ### 8\. ss (netstat) The `ss` command is a replacement for `netstat`. You can still use the `netstat` command on all systems. Using `ss` command, you can get more information than `netstat` command. ss command is fast because it gets all the information from the kernel userspace. Now let's have a look at a few usages of `ss` command. #### Listing all connections The "`ss`" command will list all the TCP, UDP, and Unix socket connections on your machine. ```bash ubuntu@devopscube:~$ ss Netid State Recv-Q Send-Q Local Address:Port Peer Address:Port u_str ESTAB 0 0 * 7594 * 0 u_str ESTAB 0 0 @/com/ubuntu/upstart 7605 * 0 u_str ESTAB 0 0 * 29701 * 0 u_str ESTAB 0 0 /var/run/dbus/system_bus_socket 29702 * 0 tcp ESTAB 0 400 172.31.18.184:ssh 1.22.167.31:61808 ``` The output of the `ss` command will be big so you can use " `ss | less` " command to make the output scrollable. #### Filtering out TCP, UDP and Unix sockets If you want to filter out TCP , UDP or UNIX socket details, use "-t" "-u" and "-x" flag with the "ss" command. It will show all the established connections to the specific ports. If you want to list both connected and listening ports using "a" with the specific flag as shown below. ```bash ss -ta ss -ua ss -xa ``` #### List all listening ports To list all the listening ports, use "-l" flag with ss command. To list specific TCP, UDP or UNIX socket, use "-t", "-u" and "-x" flag with "-l" as shown below. ```bash ubuntu@devopscube:~$ ss -lt State Recv-Q Send-Q Local Address:Port Peer Address:Port LISTEN 0 128 *:ssh *:* LISTEN 0 50 :::http-alt :::* LISTEN 0 50 :::55857 :::* LISTEN 0 128 :::ssh :::* LISTEN 0 50 :::53285 :::* ubuntu@devopscube:~$ ``` #### List all established To list all the established ports, use the `state established` flag as shown below. ```bash ss -t -r state established ``` To list all sockets in listening state, ```bash ss -t -r state listening ``` ### 9\. traceroute If you do not have a `traceroute` utility in your system or server, you can install it from the native repository. `traceroute` is a network troubleshooting utility. Using traceroute you can find the number of hops required for a particular packet to reach the destination. You can essentially trace the path of the packet from your server to the remote host. For example, ```bash traceroute google.com ``` Here is the output. ```bash traceroute to google.com (173.194.33.163), 30 hops max, 60 byte packets 1 ec2-50-112-0-84.us-west-2.compute.amazonaws.com (50.112.0.84) 1.974 ms 1.895 ms 1.899 ms 2 100.64.1.247 (100.64.1.247) 1.414 ms 100.64.1.137 (100.64.1.137) 1.127 ms 100.64.1.97 (100.64.1.97) 1.313 ms 3 100.64.0.198 (100.64.0.198) 1.443 ms 100.64.0.62 (100.64.0.62) 2.160 ms 100.64.0.60 (100.64.0.60) 2.116 ms 10 66.249.94.214 (66.249.94.214) 6.313 ms 7.104 ms 209.85.249.34 (209.85.249.34) 5.986 ms 11 209.85.244.65 (209.85.244.65) 6.157 ms 6.341 ms 6.574 m. . 12 sea09s18-in-f3.1e100.net (173.194.33.163) 6.302 ms 6.517 ms 6.071 ms ubuntu@devopscube:~$ ``` The above output shows the hop count (12) to reach google.com from devopscube AWS ec2 server. This utiltity comes in handy when you want to troubleshoot issues related to network packets not reaching the host. ### 10\. mtr The `mtr` utility is a network diagnostic tool to troubleshoot the network bottlenecks. It combines the functionality of both `ping` and `traceroute` For example, the following command shows the `traceroute` output in real-time. ```bash mtr google.com ``` Here is the output. ![mtr network diagnostic tool](https://storage.ghost.io/c/5f/2f/5f2f4d20-2abf-4534-8d40-7aa233aedd43/content/images/2025/03/mtr-output-min-2.png) #### mtr report You can generate a report using the --report flag. When you run the mtr report, it sends 10 packets to the destination and creates the report. ```bash mtr -n --report google.com ``` ![network troubleshooting with mtr report](https://storage.ghost.io/c/5f/2f/5f2f4d20-2abf-4534-8d40-7aa233aedd43/content/images/2025/03/mtr-report-min-2.png) ### 11\. dig If you have any task related to DNS lookup, you can use "`dig`" command to query the DNS name servers. #### Get all DNS records with dig The following command returns all the DNS records and TTL information of a twitter.com ```bash dig twiter.com ANY ``` ![all DNS records with dig](https://storage.ghost.io/c/5f/2f/5f2f4d20-2abf-4534-8d40-7aa233aedd43/content/images/2025/03/dig-output-min-2.png) Use `+short` to get the output without verbose. ```bash dig google.com ANY +short ``` #### Get Specific DNS Record with dig For example, If you want to get the `A record` for the particular domain name, you can use the dig command. `+short` will provide the information without verbose ```bash dig www.google.com A +short ``` Similarly, you can get the other record information separately using the following commands. ```bash dig google.com CNAME +short dig google.com MX +short dig google.com TXT +short dig google.com NS +short ``` #### Reverse DNS Lookup with dig You can perform a reverse DNS lookup with dig using the following command. Replace `8.8.8.8` with the required IP ```bash dig -x 8.8.8.8 ``` ### 12\. nslookup **Nslookup** (Name Server Lookup) utility is used to check the DNS entries. It is similar to dig command. To check the DNS records of a domain, you can use the following command. ```bash nslookup google.com ``` You can also do a reverse lookup with the IP address. ```bash nslookup 8.8.8.8 ``` To get all the DNS records of a domain name, you can use the following. ```bash nslookup -type=any google.com ``` Similarly, you can query for records like `mx`, `soa` etc ### 13\. nc (netcat) The `nc` (netcat) command is known as the swiss army of networking commands. Using `nc`, you can check the connectivity of a service running on a specific port. For example, to check if `ssh` port is open, you can use the following command. ```bash nc -v -n 192.168.33.10 22 ``` `netcat` can also be used for data transfer over TCP/UDP and port scanning. Port scanning is not recommended in cloud environments. You need to request the cloud provider to perform port scanning operations in your environment. ### 14\. telnet The telnet command is used to troubleshoot the TCP connections on a port. To check port connectivity using telnet, use the following command. ```bash telnet 10.4.5.5 22 ``` ### 15\. route The "`route`" command is used to get the details of the route table for your system and to manipulate it. Let us look at a few examples for the route command. #### Listing all routes Execute the "`route`" command without any arguments to list all the existing routes in your system or server. ```bash ubuntu@devopscube:~$ route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface default ip-172-31-16-1. 0.0.0.0 UG 0 0 0 eth0 172.17.0.0 * 255.255.0.0 U 0 0 0 docker0 172.31.16.0 * 255.255.240.0 U 0 0 0 eth0 ubuntu@devopscube:~$ ``` If you want to get the full output in numerical form without any hostname, you can use "-n" flag with the route command. ```bash ubuntu@devopscube:~$ route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 172.31.16.1 0.0.0.0 UG 0 0 0 eth0 172.17.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0 172.31.16.0 0.0.0.0 255.255.240.0 U 0 0 0 eth0 ubuntu@devopscube:~$ ``` ### 16\. tcpdump The `tcpdump` command is primarily used for troubleshooting network traffic. ****Note:** To analyze the output of `tcpdump` command requires some learning, so explaining it is out of the scope of this article. `tcpdump` command works with the network interfaces of the system. So you need to use administrative privileges to execute the command. #### List all network interfaces Use the following command to list all the interfaces. ```bash sudo tcpdump --list-interfaces ``` #### Capture Packets on Specific Interface To get the dump of packets on a specific interface, you can use the following command. ****Note:** press `ctrl + c `to stop capturing the packets. ```bash sudo tcpdump -i eth0 ``` To limit the packet capturing, you can use the `-c` flag with the number. For example, ```bash sudo tcpdump -i eth0 -c 10 ``` #### Capture Packets on All Interfaces To capture packets on all the interfaces, use the `any` flag as shown below. ```bash sudo tcpdump -i any ``` ### 17\. lsof `lsof` is a command that would used in day to day linux troubleshooting. This command is equally important for anyone working with Linux systems. To list all open files, execute the `lsof` command. ```bash lsof ``` One of the common error face by developers & DevOps engineers is "**Bind failed error: Address already in use**". You can find the process ID associated with a port using the following command. The you can kill the process to free up the port. ```bash lsof -i :8080 ``` ### 18\. resolvectl With resolvectl you can checks DNS configuration and status in systems using `systemd-resolved`. ```bash $ resolvectl query devopscube.com devopscube.com: 151.101.67.7 -- link: enp1s0 151.101.3.7 -- link: enp1s0 151.101.195.7 -- link: enp1s0 151.101.131.7 -- link: enp1s0 2a04:4e42:600::775 -- link: enp1s0 2a04:4e42::775 -- link: enp1s0 2a04:4e42:400::775 -- link: enp1s0 2a04:4e42:200::775 -- link: enp1s0 -- Information acquired via protocol DNS in 82.9ms. -- Data is authenticated: no; Data was acquired via local or encrypted transport: no -- Data from: network ``` It basically replaces the older /etc/resolv.conf based checks in modern systems ## Bonus Tools for DevOps/SRE There are more networking troubleshooting command-line utilities available from third-party solutions. You need to install them separately and use them for your troubleshooting purposes. Due to security compliance reasons, not every organisation will allow you to do it. However, if you have to option to use third-party tools, you can explore them. We have organized some tool information under different categories in the following table. | Category | Open-Source Tools | | ------------------------------- | -------------------------------- | | **Network Scanners** | Nmap, Zenmap (GUI for Nmap) | | **Packet Analyzers** | Wireshark, Tcpdump | | **Bandwidth Monitors** | BandwidthD, Cacti | | **Port Scanners** | Nmap, Masscan | | **Ping/Traceroute Tools** | MTR (My Traceroute) | | **Wireless Network Analyzers** | Wireshark (for wireless), Kismet | | **Network Simulators** | GNS3, Mininet | | **DNS Performance** | DNSperf, dnstop | | **Network Performance Testing** | iperf3, netperf | ## Conclusion In this article, we have covered the important Linux command-line utilities for **network troubleshooting and configuration.** If you are getting started with system administration, DevOps, or SRE roles, it is essential to learn about these utilities to support the projects you are working on. Each utility has many functionalities, and you can explore further to meet your requirements. If you think we missed any important commands, let us know in the comments section. Also, if you want to learn shell scripting, check out our guide on [how to learn shell scripting](https://devopscube.com/linux-shell-scripting-for-devops/). If you are developers, check out my guide on [Linux Commands ](https://devopscube.com/list-of-linux-commands-every-developer-should-know/)every Developer should know.