Determine the network and IP configuration of your own client

A network and IP configuration include various information that you need again and again. Among other things, if you want to find out if your own network configuration is complete and correct. Only then is participation in the network possible.

task

1. Determine the MAC address of your client.
2. Determine the private IPv4 address of your client.
3. Determine the public IPv4 address of your client.
4. Determine the subnet mask?
5. Determine the link-local IPv6 address of your client.
6. Determine the global IPv6 address of your client.
7. Determine the length of the prefix.
8. What is the IP address of the default gateway?
9. What is the IP address of the DHCP server?
10. What is the IP address of the DNS server?

Solution with Windows 7 (ipconfig)
Entering “ipconfig / all” in the command prompt (Start menu: Run “cmd”) on Windows 7 results in the following output:

ipconfig/all

Windows IP Configuration
   Hostname. , , , , , , , , , , , , : CLIENT
   Primary DNS suffix. , , , , , , :
   Node type. , , , , , , , , , , , : Hybrid
   IP routing enabled. , , , , , , : No
   WINS proxy enabled. , , , , , , : No
   Ethernet adapter LAN connection:
   Connection-specific DNS suffix: t-online.de
   Description. , , , , , , , , , , : Intel (R) PRO / 100
   Physical address. , , , , , : 68-A8-6D-34-34-18
   DHCP enabled. , , , , , , , , , : Yes
   Autoconfiguration enabled. , , : Yes
   IPv6 address. , , , , , , , , , , : 2001: db8: 1: 1: 2570: 79ba: 984b: f44b (preferred)
   Link-local IPv6 address. , : fe80 :: 2570: 79ba: 984b: f44b% 1 (preferred)
   IP address. , , , , , , , , , , , : 192.168.168.107
   Subnet mask. , , , , , , , , , , : 255.255.255.0
   Lease received. , , , , , , , , , : Tuesday, August 30, 2014
   Lease expires. , , , , , , , , , : Tuesday, August 30, 2014
   Standard gateway. , , , , , , , , : fe80 :: 2b7: 4aff: fe34: 09e4% 1
                                       192.168.168.8
   DHCP server. , , , , , , , , , , : 192.168.168.8
   DNS server. , , , , , , , , , , , : 192.168.168.8

From this, the following information can be drawn:

• a. MAC Address: 68-A8-6D-34-34-18
• b. IPv4 address: 192.168.168.107
• c. no public IPv4 address
• d. Subnet mask: 255.255.255.0
• e. Link-local IPv6 address: fe80 :: 2570: 79ba: 984b: f44b
• f. Public IPv6 Address: 2001: db8: 1: 1: 2570: 79ba: 984b: f44b
• G. Prefix: 64
• H. Default Gateway: fe80 :: 2b7: 4aff: fe34: 09e4 (IPv6) and 192.168.168.8 (IPv4)
• i. DHCP server: 192.168.168.8
• j. DNS server: 192.168.168.8

Solution with Linux and Mac OS (ifconfig, route, …)
Typing “ifconfig” on Mac OS produces the following output:

ifconfig

en1: flags = 8863 <UP, BROADCAST, SMART, RUNNING, SIMPLEX, MULTICAST> mtu 1500
   ether 68: a8: 6d: 34: 34: 18
   inet6 fe80 :: 6aa8: 6dff: fe34: 3418% en1 prefixlen 64 scopeid 0x5
   inet 192.168.168.107 netmask 0xffffff00 broadcast 192.168.168.255
   nd6 options = 1 <PERFORMNUD>
   media: autoselect
   status: active

From this, the following information can be drawn:

• a. MAC Address: 68: a8: 6d: 34: 34: 18
• b. and c. IPv4 address: 192.168.168.107 (private only, no public address)
• d. Subnet mask: 255.255.255.0 or 0xffffff00
• e. and f. IPv6 address: fe80 :: 6aa8: 6dff: fe34: 3418 (link-local only)
• G. Prefix: 64

For the standard gateway, we still need the command “route”, which gives us information about the routing. Among other things, the default route 0.0.0.0 is entered here.

route -n

Kernel IP routing table
   Target Router Genmask Flags Metric Ref Use Iface
   0.0.0.0 192.168.168.8 0.0.0.0 UG 0 0 0 eth0
   192.168.168.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0

• H. Default gateway for default route 0.0.0.0: 192.168.168.8

The address of the DNS server can also be determined from the file shown above. If the IP configuration was made manually, you have to view the contents of another file.

cat /etc/resolv.conf

domain internally
search internally
nameserver 192.168.168.8

• j. DNS server: 192.168.168.8

Alternatively, you can also look directly into the file with the network settings.