How to know Router's IP what connect to Modem - networking

I have a network like that:
Internet <-> Modem <-> Router (broadcast wifi)
I'm using Windows. If I use command: ipconfig, I only know Modem's IP through info of Default Gateway.
So, how to know the Router's IP in this network.
Thanks.

If you want to know the external (from the Internet IP) you can browse to http://www.whatismyip.com/ and check it there.
Or
You can check it inside the router's configuration page. Unfortunately you can't simply know it by being a member of its network since this is a limitation of the NAT and the IP protocol.
If you wish to know the router's IP inside the internal network of the router .
when running ipconfig it should be the Default Gateway entry.

If you know your IP and you know your Netmask, then you can easy find out the subnet. The Router's IP is "always" the first avaible IP in the subnet. Thats the case for your private IP.
For the public IP you can try a service like this one.

Related

Accessing connected devices to a local network wirelessly

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).

My Router Internet IP is different from my public IP

I am running a ddns client on Ubuntu for Nextcloud server, however my ISP has done something to the router so internet IP showing in the router is different from my public IP which causes an issue when ddclient updates the IP of my domain.
I have tried to contact my ISP but they want me to pay a huge amount for a fixed IP.
Is there any solution for this?
My router model is HG8245Q2.
*PS: The IP shown in the image is just an example.
Note: I tried this on a another router model HG8245Q, and it gives me the same IP on both router and google. so no issue on the old router model.
The IP address you see in your router is just another internal IP address from private range 10.x.x.x
This means your router is not connected directly to the internet but to another subnet of your ISP. And only this subnet is connected to the internet over another router (with NAT) and this router has a public IP address.
This is standard behavior with most of ISP because they have limited count of public IP addresses. If you need public IP, you have to pay for it, change ISP who gives you one for free or try some edge case solution like rent VPS server and make VPN tunnel to your home router (this requires advanced networking skills)
Maybe DDNS comes in handy for you. You can opt for free DDNS services like DynDDNS or NoIP.
Steps [I personally prefer noip.com ]:
Create a Free Account
Choose a hostname(We can say a domain name pointing towards ur system IP)
Download their desktop client(To sync your Dynamic IP with the hostname you selected)
Boom it's done! Use that hostname instead of IP wherever needed, traffic will be redirected to your system. Just take care of port forwarding and firewall settings.

Cannot access machine via DNS in the private network

I have a machine in my private network with IP 192.168.1.10
I have a DNS name, "toto.mydns.com", a DNS client is running on the machine.
I configured the router for Port forwarding.
I can access the machine when i am outside my home, when using a pulic IP address it works but when i am at home and i get a dynamic IP address trough DHCP from my router, i cannot use toto.mydns.com anymore, i must use 192.168.1.10 to access.
I would like to know if i need to configure something on the router for that ?
Thank you !
toto.mydns.com will resolve to your external public IP
There will almost certainly be nothing routing that IP through to your router, and thus through NAT to your internal address.
The easiest way to resolve this (Pun very much intended) is to have a hosts file entry on your computers running inside your network so that they resolve the same DNS address to the internal address.
A much harder, but more fun, way would be to set up your own DNS server inside your network, have the DHCP dish it out as the primary DNS server for your network and put in an entry for your internal address :D
Have fun...
Toto.mydns.com is accessible from outside,this DNS is assigned on a machine with a static IP address(sorry not dynamic),so the IP of this machine is 192.168.1.10.
Whrn i am at home in my private network i need to enter 192.168.1.10 and toto.mydns.com does not work.Any help???

Cisco VPN IP address

I've some doubts about a VPN.
I've been given a Cisco VPN client to connect to the LAN of my society. I use this to connect to a local server. I don't understand how the VPN is working.
I'm at home now. In the VPN Client I see an IP. If I go to http://www.whatismyip.com/ I see another IP, which is the IP I've when I'm also without the VPN Client, while I expected to see the IP of the VPN Client. If I use $_SERVER['REMOTE_ADDR'] I see another (third!) IP, while I expected the IP I see in the VPN Client.
Can you clarify please?
I need this to know if I'm identifies always from the same IP from the local server.
If I'm not mistaken, this should be correct. Please correct me if I'm wrong.
By default you have 2 IP addresses.
Local IP: IP address used to identify yourself within your LAN.
Global IP: A public IP used to gain access to the internet. At home it will most likley be a public IP NATTED* by your ISP.
Because you're also using a VPN connection, you'll receive a third IP.
Local IP for VPN: IP address used to identify yourself on the other end of the VPN.
*NAT = Network Address Translation

Can I configure network broadcast address on Cisco ASA device

Working on Cisco ASA 5510 device I tried to use the broadcast IP address of a Public Network for NAT Static configuration and IOS allowed me to do it, but from outside it didn't work. After a while I changed the broadcast IP to an usable IP and it started to work.
I understand that on a physical interface we can't configured a broadcast IP address, but for NAT we have to do it, otherwise we loose many Public IP addresses from networks with /29 prefix.
I understand you need to squeeze one more IP address for you to use, however most routers don't support forwarding broadcast traffic, for a simple fact, if that is allowed, anyone can send a ping to someone's broadcast address and every host in that subnet has to reply, that is not acceptable.
Other Internet routers may not tell that IP address is broadcast or not, but think about your ISP router for your access circuit, it has to know that IP address is a broadcast, it has to know your ip range in order to set it up. And when someone send you a ping, the router will say: hey, that is a broadcast address on my client's interface, first thing I know as a router, I must not forward a broadcast, thus drop it.
Hope it helps.

Resources