What is a Dynamic Host Configuration Protocol(DHCP) server? and What is the difference between DHCP server and
a Domain Name Server(DNS) server?
DHCP (Dynamic Host Configuration Protocol)
is for assigning IP addresses (or other network parameters) to devices so they can communicate with each other.
If you for example want to establish a wireless connection, then you need amongst other things request a DHCP server that assigns your device an IP address so you can communicate with other nodes.
DNS (Domain Name System)
is a hierarchical decentralised service which associates informations with domain names.
If you for example want to request google.com you first need to figure out what the corresponding IP address is. Therefore you request a DNS server.
DHCP is a layer 2 network protocol that will offer IP address from its pool to device not connected to the network, but who wanted to. It's used in LAN network.
DNS is like a dictionary. Consider you are trying to go to stackoverflow.com, so your device isn't able to know what's the IP address of stackoverflow.com. He will ask to DNS server to found the IP address for him.
DHCP = IP dynamic allocation
DNS = IP retrieval of an existing and registered device
Related
I am making an application which will start a HTTP server on a hard-coded port (assume the port is 32654)
There can be multiple clients on the same network which will try to search for this HTTP server. Since they don't know the server IP address, they will need to parallelly scan on each IP address from xxx.xxx.xxx.1 to xxx.xxx.xxx.254 at port 32654. (assume the subnet mask is 255.255.255.0)
Question-1) If the server finds that 32654 port is already taken by another application, it will need to start on other port. How should I re-design my IP address & port scanning logic in my client to efficiently search the new server port and IP address..
Question-2) If it is a large network and the subnet mask for the network is 255.255.0.0, is there an efficient way to search the correct IP address across this vast new search space?
Hello Everyone!
I want to know that is there any way to access a photocopier machine which is connected to a computer through Ethernet wire and that computer is connected to my WiFi network?
P.S: What if I don't know the IP assigned to that Photocopier machine?
If the wireless network is part of the wired network you should have any problem reaching the photocopier.
If you don't know the IP address, you can reach it by host name if the DHCP and DNS are working properly. If you are on an Active Directory infrastructure and DHCP and DNS are integrated it should be transparent.
If you are on your home with a "home" router they usually do the hostname to IP resolve (DNS).
You can nslookup hostname in your machine to see if your dns is resolving the ip address. you can also ping hostname or ping ip address to test that you can reach the desired host. Some hosts block ping (ICMP) requests, please note that ping is ping does not respond is not a definitive solution.
Please note that in your home router you should use your router or default gateway to be the DNS also, and then add the google public DNS or your ISP.
Also when connecting the access point to an existing network you may have 2 DHCP servers providing IP addresses to hosts, you should disable DHCP on the Access Point and connect the AP to the network using the switch port and not the WAN port (the WAN port will try to do NAT and assign a different set of IP addresses).
I am facing a very strange problem. I have a task to establish a TCP connection to a server who has a trusted IP. And I have to run the code in a host with private IP address. The trusted IP is 10.10.10.15, which is also a private IP. And the question arises that the IP address of my host and the trusted IP is not on the same network. To be specific, my IP address is 10.0.35.1/24. Please let me know if there is any solution to this problem
Presumably these subnets, i.e. 10.10.10.0/24 (?) and 10.0.35.0/24, are part of your local network. You will need a Layer 3 device to perform inter-VLAN routing.
This will be a router with Layer 3 VLAN interfaces, in the Cisco world they would be SVIs, that would be acting as the default gateway of the subnets in your network. What happens is all traffic that needs to go between two hosts between different networks, has to go through their default gateway and it will be routed to the destination network/VLAN.
As long as the network devices between the two clients are able to route packets between these networks, the hosts will be able to reach each other. In your code, you simply need to specify that these packets need to go to the private IP address of the other host.
Im new to networking,If I have a window server and in that server I have a normal soho router, will that server assign the ip address to each device? or will that router do it. What I've learned is that the server is suppose to be the DHCP but sometimes if you plug a router directly in the server it kicks the server off and the router starts to assign the ip address. If that is so, how would you fix that?
Most routers will take on the role of a DHCP Server out-of-the-box. That is, they will distribute ip addresses to whatever DHCP Client requests an address.
By default, a Windows server will not have set up a fully configured DHCP Server.
By default a Windows machine (either client or server) and most other networked devices will have set their network interface to be a DHCP Client.
Therefore, by simply plugging in your Windows server to one of your router's LAN ports will make the router set the Windows server's network interface to the next available ip address using DHCP.
If you were to connect more devices to the router's LAN ports it will still be the router that assigns those extra devices an ip address.
Ideally you want only one DHCP server in your network.
Also, if you want your Windows server to always have the same ip address you can do two things:
Log in to the router and set a fixed ip address for your Windows server network card's unique MAC address.
Modify the router's DHCP range (e.g. from .10 to .200) so it leaves some addresses free (e.g. .1 to .9 and from .201 to .254). Then set your Windows server network card's fixed IPV4 address to a fixed address (e.g. .210). You may also need to set a DNS server then.
This is only briefly skimming the subject of IPV4 networks, DHCP and friends so when you have some time try to read the wikipedia pages for them.
http://en.wikipedia.org/wiki/IPv4
http://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol
Server assigns your public IP address, in fact it assigns your router a public IP address.
While the router assigns each device connected a local IP address.
With respect to your router, the IP address server assigns it is its IPv4 address and the addresses router assigns to its clients are IPv6 address.
When you browse the internet through your router, the router reads your requests and responds according to that IPv6 address and when the router requests something to the server, server sees it as its IPv4 address. :)
I'm having a static IP address, say:127.254.x.x
Is it possible to access my web application from some other place by just replacing the local host with my IP???
Also, what will I replace the local host with if Ithe server is on a wifi network.? I.e. The router assigns a different ip to my server(because of dhcp) other than my original static ip. In this case should it be
192.x.x.2:8090
Or
127.254.x.x
Any help is appreciated.
I'm having a static IP address, say:127.254.x.x Is it possible to access my web application from some other place by just replacing the local host with my IP???
Yes, provided you configure it correctly.
Normally, you have a broadband modem/router which talks to the outside world, and provides a NAT network range to your devices. So you have an external IP address (the one the modem/router uses to talk to the outside world), and probably several internal IP addresses (for your phone, your laptop, your other laptop, your Kindle, etc.).
So to access a web server on your internal network from the outside world, you have to do two things:
Configure your modem/router to "forward" traffic it receives on the desired port (port 80 for HTTP) to the server on your network. How you do this depends on your modem/router. Look for "port forwarding."
When trying to access the app from the outside world, use your external, not internal, IP address.
So for instance, if your external IP address is 222.111.222.12, and the IP address of the machine you're using as your web server is 127.154.0.23, then you tell your modem/router that whatever traffic it receives on port 80 it should forward to 127.154.0.23 (this configuration may be by IP address, or may be by the MAC address of the network card in your web server machine; it depends on the modem/router). Then to view your app from outside your network, you go to http://222.111.222.12 (or whatever name you assign that IP address to in DNS).