IP Addressing is one of the most important lessons in networking and for CCNA 200-301. We can manually assign an ip address to the devices or we use DHCP Servers to do this. The first one is static ip addressing and the second one is dynamic ip addressing. We know how to configure static ip addressing or how to set up a DHCP server for this role. How about verification? How can we verify IP parameters for client OS? How can we verify ip addressing in Windows, Linux and MacOS? In this lesson, we will focus on IP parameters verification on different client OS like Windows, Linux and MacOS.
IP address verification is often the first step of any network problem troubleshooting. First of all, we check the ip address of the devices in the network and we verify ip reachability. To do this in different Client devices, we need to know how to verify IP parameters for Client OS for different Operating Systems. Here, we will learn these steps.
Table of Contents
Windows is one of the most used operating system by users in the World. To verify windows IP parameters, we have two important commands. These are:
With “ipconfig”, we can check IP parameters configured on the client device. We can use only “ipconfig” command or we can use it with “all” keyword.
With “netstat”, we can view important information about networking. We can do this by using different parameters with netstat command.
If we do not use any parameters with netstat, it gives us the statistics and current TCP/IP network connections
To view ethernet statistics, we use “netstat -e” command.
C:\Users\asus> netstat -e
Bytes 605777019 136248929
Unicast packets 798603 526038
Non-unicast packets 63 13254
Discards 0 0
Errors 0 0
Unknown protocols 0
To display all the connections and listening ports, we use “netstat -a” command.
C:\Users\asus> netstat -a
Proto Local Address Foreign Address State
TCP 0.0.0.0:135 LAPTOP-73BD6FUS:0 LISTENING
TCP 0.0.0.0:445 LAPTOP-73BD6FUS:0 LISTENING
TCP 0.0.0.0:902 LAPTOP-73BD6FUS:0 LISTENING
TCP 0.0.0.0:912 LAPTOP-73BD6FUS:0 LISTENING
TCP 0.0.0.0:5040 LAPTOP-73BD6FUS:0 LISTENING
TCP 0.0.0.0:7070 LAPTOP-73BD6FUS:0 LISTENING
TCP 0.0.0.0:17500 LAPTOP-73BD6FUS:0 LISTENING
TCP 0.0.0.0:49664 LAPTOP-73BD6FUS:0 LISTENING
TCP 0.0.0.0:49665 LAPTOP-73BD6FUS:0 LISTENING
TCP 0.0.0.0:49666 LAPTOP-73BD6FUS:0 LISTENING
TCP 0.0.0.0:49667 LAPTOP-73BD6FUS:0 LISTENING
TCP 0.0.0.0:49668 LAPTOP-73BD6FUS:0 LISTENING
TCP 0.0.0.0:49670 LAPTOP-73BD6FUS:0 LISTENING
TCP 0.0.0.0:49671 LAPTOP-73BD6FUS:0 LISTENING
TCP 0.0.0.0:49672 LAPTOP-73BD6FUS:0 LISTENING
TCP 10.0.33.57:139 LAPTOP-73BD6FUS:0 LISTENING
To view routing table, we use “netstat -r” command.
With “netstat -n”, we displays addresses and port numbers in numerical form.
C:\Users\asus> netstat -n
Proto Local Address Foreign Address State
TCP 10.0.33.57:51224 220.127.116.11:443 CLOSE_WAIT
TCP 10.0.33.57:51233 18.104.22.168:443 CLOSE_WAIT
TCP 10.0.33.57:51249 22.214.171.124:443 ESTABLISHED
TCP 10.0.33.57:51254 126.96.36.199:443 CLOSE_WAIT
TCP 10.0.33.57:51269 188.8.131.52:443 CLOSE_WAIT
TCP 10.0.33.57:51312 184.108.40.206:443 ESTABLISHED
TCP 10.0.33.57:51326 220.127.116.11:443 ESTABLISHED
There are different ip addressing problems in a network. Here, we will focus on some of these network problems.
Duplicate IP address one of the most faced network problems. Especially when you add a new device to a network, this problem can occur. The existing configuration in this device or the open DHCP Service on this device can cause this Duplicate IP Address problem.
TO avoid from Duplicate IP address problem, before adding a new device to your network, disable its DHCP service. And if you have some manual ip configurations, check your network’s ip addresses good.
DNS Problem can be another problem that we face in network environments. DNS configuration is done on DHCP Server. If there is a wrong configuration on this part, your DNS service will not work for your device.
If you have such a problem in your network, the first thing you should check is DNS settings on your DHCP Server.
There can be different reasons of IP Address exhaustion. Maybe, there is a connection failure to DHCP Server and your device can not reach to DHCP Server to get an ip address. Or your DHCP server has a small DHCP pool that has very few ip address that do not enough for your network.
If your device can not get an ip address from your DHCP Server, it uses APIPA addresses. APIPA addresses are the addresses inside the range 192.168.x.x/24.
If you have such an ip address exhaustion, you can check your DHCP Server connections or you can check the configuration of your DHCP Server.