All Questions
289 questions
0
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0
answers
36
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Connect two devices with different subnets
I have a problem where I need to connect one system to another that exist on different networks. How do I do this. I have tried using this NAT configuration:
iptables -t nat -I PREROUTING -d 192.168.1....
- 1
1
vote
0
answers
26
views
Ping the uplink device via NAT
I have two routers. One is connected to the Internet, has a WAN IP XXX.XXX.XXX.XXX, internal IP 192.168.10.1, and DHCP server 192.168.10.*
The second router connects to the first one via WAN and gets ...
- 111
0
votes
0
answers
951
views
Can you run a VPN behind a double NAT?
I heard a double NAT can introduce problems with VPNs, but I don't understand why. I want to have a LAN behind a double NAT that can be connected to using a VPN.
My desired network would look ...
- 13
0
votes
0
answers
400
views
TP-Link omada ER706W gigabit VPN router configuration
I want to replace the router I bought with the router given by my service provider. The router my service provider gave me was specially produced and its name is TP-Link Archer C5v. The router I ...
0
votes
1
answer
470
views
NAT off on main router but second two routers will have NAT any Security Concerns?
This is what i've read somewhere
( Instead of turning off NAT on the main router, you may consider configuring the main router to pass through the necessary traffic to the two other routers without ...
1
vote
0
answers
95
views
Cannot access internal network server from internal network device using public IP
I cannot access server2 from my laptop under the office network using public external IP address.
And here is my experiment
Case
From
To
Command
Connection
Case 1
L
server1
ssh [email protected] -p ...
- 11
0
votes
0
answers
44
views
Getting 2 PFSense routers to communicate with eachother
I have two routers. R2 can communicate with R1 but R1 can not communicate with R2. I know that we are supposed to resolve this with static routes. I have a screenshot showing all my work. What am I ...
2
votes
1
answer
297
views
How does remote users connect to a device on a local network behind NAT without port forwarding or VPN? [closed]
How would someone at tech support for a product (assume for now any generic ethernet/wifi connected device) remotely access the device needing troubleshooting when the device is connected to a local ...
- 83
0
votes
1
answer
128
views
Creating an IP alias for a device on another subnet behind a VPN
I set up a site-to-site VPN with IPsec between two routers.
Router 1 (DLink DSR-250V2) controls the 11.11.11.0/24 subnet.
Router 2 controls the 192.168.1.0/24 subnet.
The tunnel itself works fine. ...
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1
vote
0
answers
859
views
How to setup two routers seamlessly without having double NAT
I have two wireless routers, a generic one provided by ISP which is GPON ONU/Wireless router and a TP-Link.
I need an upgrade because the generic one provided by the ISp unfortunately has several ...
- 111
1
vote
1
answer
138
views
In Linux how to loop-back the internal traffic that's destined to the server's own NATed public IP?
By internal I mean only the traffic originating within the server itself (not LAN or other servers). I have a cloud VM where the Public IP provided by the cloud vendor is not directly attached to the ...
- 35
0
votes
1
answer
477
views
Best way to access my computer/network from anywhere while having public IP. ISP uses NAT
I'd like to be able to access my home computer/devices from anywhere with remote desktop on my tablet, I tried using a free DDNS to see if that would work but I realized my router is behind NAT so the ...
- 325
0
votes
0
answers
65
views
Port forwarded public IP not reachable from private network but from outside
I am using double NAT, I can not put my provider provided modem in bridge mode so I put my unifi USG in it´s DMZ.
On my USG I set up forwarded ports, before I migrated my subnet away from a 10.0.0.0/8 ...
- 101
0
votes
1
answer
381
views
Internet connection activ only after restart of nftables
I configured a DIY Debian-based router without DHCP and DNS server.
MY PROBLEM:
When I switch on the router and the system boots, the Internet connection on clients becomes available for 4 -5seconds (...
- 1
1
vote
1
answer
383
views
Connect multiple devices behind single LAN IP Address
I'm looking for some enlightenment / validation on the best way to approach this problem.
I've several measurement devices that are connected to a computer (call it the "main" computer) ...
0
votes
1
answer
291
views
How iptables SNAT deal with src port dilemma between port translation fr local ip and DNAT rule that forwards all traffic to the same local ip?
Say we have a Linux based router with WAN interface eth0 ip addr 4.3.2.1 (w/ whatever gw ip) and LAN interface eth1 ip addr 192.168.51.1/24, which means we need an iptables rule below to make the ...
14
votes
2
answers
5k
views
How does the airconditioner app on my phone access my aircon controller through my router?
I understand how a router uses NAT/NAPT to enable a client on my home network to request a packet from an external server, and hence how the router knows to which client to send the packet that is ...
- 141
-2
votes
1
answer
742
views
Can't ping my external CGNAT IP address from external network [duplicate]
I'm new to networking and I'm trying to scan my external IP from an external network.
I first tried finding my public IP from whatismyIP.com. The IP address on that site was different from the ...
0
votes
3
answers
245
views
How routers deal with only one external IP?
I recently discovered that all my devices connected to a WiFi router have the same external IP. Call it 20.20.20.20. The thing that I don't understand is how the router figures out which IP packet ...
- 133
-3
votes
1
answer
575
views
Can router give the same public IP to 2 different networks? [closed]
I have set up a virtual machine and specified an IP address for it that is outside my home network. I cannot ping this machine and access it through the Internet from my host machine. I presume it is ...
- 105
0
votes
1
answer
400
views
NAT masquerade refuses to work on Link-Local network
I am developing a device, in terms of usage and network connectivity it is similar to a printer with an Ethernet port. This device should also work in p2p scenarios, i.e. when the Ethernet port of the ...
- 113
0
votes
1
answer
378
views
NAT not working properly with more LANs - source address is replaced with LAN gateway IP
Running Mikrotik RouterOS, does not matter if version 6.48 or 7.9.
What works:
Default configuration makes NAT keep source address (i.e. public IP of client which connects to server, chain: input - ...
- 3
0
votes
1
answer
2k
views
Is it possible to enable UPnP without going into Router web interface?
So I lost the password for my router, and I am living in a rural area, so contacting the ISP is a hassle. I was wondering if it is possible to enable UPnP option without accessing the router settings. ...
-1
votes
1
answer
1k
views
How to access JioFiber's admin panel remotely?
I want to access my JioFiber router's admin panel from the internet. Can't simply forward the port because the ISP's using Carrier Grade Network Address Translation (CGNAT).
I don't have access to the ...
- 39
0
votes
1
answer
68
views
Remote administration between 2 host behind different NAT
I have 2 computers, both connect to the internet using different routers in different locations, therefore not having a fixed public IP address.
Computer A is the admin Pc and needs to get a shell on ...
- 49
1
vote
1
answer
178
views
How can I get connection attempts behind a NAT router?
I've been playing with nftables recently and set up logging every incoming TCP SYN packet to my local machine. I noticed every minute I get a couple of random connection attempts on various ports (...
1
vote
0
answers
543
views
Public IP configuration on Home router ( TP-link 940N)
I got 196.188.173.32/30 ip adress from my ISP with the following configuration.
Wan ip : 10.126.10.158/29
Gateway : 10.12.10.157
Lan Ip : 196.188.173.32/30
I have configured the router per the ISP,...
- 111
0
votes
0
answers
404
views
Access home web services remotely with DDNS and NAT forwarding
I have a local server running a couple of web service on different ports. The server is connected to a router so I can access these if I am on the same LAN.
The server has a static local ip: 192.169....
- 113
0
votes
0
answers
660
views
Unable to get access to router home page after disabling NAT
I have a private home network using a single NETGEAR cable router. I accidentally disabled NAT in the router's home page, and after that I cannot access the home page anymore.
The thing is that I was ...
- 1,670
0
votes
1
answer
816
views
Why does double-NAT networking intercommunication works only in one direction?
So I set up a simple network: first comes the modem, then comes the router and behind the router my end devices. I can access the modem network from my local area network behind the router, but when I ...
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4
votes
0
answers
134
views
How packets are delivered from server to local network?
I am new to networking and am trying to understand how packets are routed on the way back from the server. I learned that when packets go out from the local network, the source address is translated ...
- 41
0
votes
1
answer
1k
views
How can one open port 51820 to the internet behind a a CGNAT
I have a raspberry pi 400 running pi-hole which is working perfectly, I want to access my home network for the internet by using PiVPN running on the same raspberry pi but I am behind a CGNAT with a ...
0
votes
0
answers
78
views
Why did my external IP stop working from within my network, when it worked before?
I host a website from a computer in my home network. For the past year or so, I could connect to it with the external IP/domain name from within the network. Now (after no changes) I can only use the ...
- 101
0
votes
1
answer
742
views
Secure DNS, NAT, DSNMASQ, and local addresses
My home network consists of an ISP supplied router, a Raspberry PI providing DHCP, DNS with dnsmasq, including local addresses behind NAT. Some weeks ago, I noticed that when I tried to connect to my ...
- 103
2
votes
1
answer
986
views
When I set up port forwarding on my home router, why does connecting to a local server via the public IP show the router's address as the client IP?
I'm trying to understand how NAT works on a basic level within my home network (just a consumer Google Fiber router with no custom configuration other than the port forwarding I'm about to describe). ...
0
votes
1
answer
1k
views
What is the name of a Network Switch that can do NAT and DHCP? [closed]
I have an industrial system composed of several devices (ip-cameras, PC, ethernet sensors...). Unfortunately most of them don't have DHCP or don't have a hostname. Thus, I cannot install this system ...
- 2,937
1
vote
1
answer
616
views
Unable to connect to device which is on the same router in network using external IP and external port
I am not sure if this is the right place to ask this question but here goes.
I have a modem with ONR fibre connected to the internet.
It has 4 Lan ports. 1, 2, 3, 4.
I have 1 PC and 3 routers ...
- 257
0
votes
1
answer
2k
views
Cannot access my public IP outside the network
So I want to test opening one port to the public. I know how to do port forwarding in the router and I have done so. I tested this with gameranger and it works. I check my global IP, say it is 121.111....
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0
votes
1
answer
68k
views
Port forwarding on ZTE router
I'm trying to forward the following ports on my ZTE router (as per PlayStation's recommendations):
TCP: 80, 443, 3478, 3479, 3480
UDP: 3478, 3479
The manual for my router gives very limited ...
user1634332
0
votes
0
answers
1k
views
Can I have 2 routers in a network without bridging
My ISP-supplied router is very bad. I have a lot of issues with the NAT rules, NATLOOPBACK, UPNP ...
I will buy another one (Router 2). I have to keep the old one connected as a master (Router 1).
I ...
- 91
0
votes
0
answers
503
views
How does Resilio Sync connect from the internet when there's a firewall and no port is listening?
Resilio Sync, formally BitTorrent Sync is able to somehow find a way around 2 NAT firewalls I have all while no port is setup to listen externally nor port forwarding on the routers. When I say I have ...
- 195
0
votes
1
answer
6k
views
What exactly is router cascade option doing? [duplicate]
I'm trying to understand what exactly happens when routers are cascaded. All description I can find state that it is done when I want to connect router to router but I can do it without any setup.
So ...
- 835
0
votes
0
answers
561
views
Ubuntu Router, cant make NAT work LAN/WAN interface
Im trying to make my own router using Ubuntu 20.04.2 LTS
I have followed this guide: https://kifarunix.com/configure-ubuntu-20-04-as-linux-router/
The only difference between his setup and mine is ...
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1
vote
1
answer
2k
views
Bridging router without a bridge mode
My ISP-supplied router is very buggy and has various issues with port forwarding and NAT loopback which they can't fix (even after sending a replacement, it had the exact same issue), so I've decided ...
- 2,468
0
votes
1
answer
1k
views
How to open my NAT type on PC?
As a gamer it is really frustrating to have a NAT type that's "strict", as it makes it really hard to find games/matches with other people online. After some research I came across something ...
- 111
0
votes
1
answer
147
views
How does the router not have conflicts with other devices as it is using the same public IP address? (NAT)
So I've been learning about NAT and how it allows us to reuse IPv4 addresses by using a NAT table and having basically an alias for the private IP to a public IP and vice versa along with storing the ...
0
votes
0
answers
34
views
How to connect 12 devices with identical IPs on a single network when device IPs can't be changed?
I have a customer who has 12 PLCs (Programmable Controllers) on his shop-floor. All these PLCs have identical IPs, and cannot be changed for some reason. My task is to access information from all ...
- 1
0
votes
0
answers
106
views
Webhosting on a "Double NAT" network behind Altice One Gateway
I have a home network with a small web-server hosted behind a LAN-WAN cascaded router. The port forwarding rules on my Altice One router point traffic on port 8080 to my cascaded routers port 8080 ...
- 101
0
votes
1
answer
3k
views
Port forwarding and NAT using pf on freebsd
I have a network router that connects three networks with the outside world. One of the internal networks is public facing the other two are not and connected via NAT. I am part of a larger network ...
- 213
0
votes
1
answer
498
views
Am I doing anything wrong with my double NAT?
I have added two routers in double NAT configuration, in order to protect my inner network from some risky devices that exist on my outer network (the private network of my internet-facing router).
(...
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