Networking – Connection to the NAS via a reverse proxy on an external VPN

Being behind a 4G-ISP with CGNAT, I cannot connect to my QNAP 269L NAS from the Internet.
I have configured a Raspberry 3B + as a VPN server with friends, with a fast Internet connection.
Could some of you brilliant people give me step by step instructions on how to configure this, so that I can connect to my NAS from the Internet, via this OpenVPN server (piVPN)?
If I understood days of searching on Google, I need to configure a reverse proxy and some sort of port forwarding on the piVPN server and iptables, but I couldn't get anything to work , due to lack of knowledge …
Thank you very much in advance, Mitscha, Denmark

networking – Can't download to wordpress from a home connection?

I have this really strange problem. I have several wordpress blogs, all on independent hosting (hostgator and GCP).

I am unable to upload images larger than 500 KB to a blog via the rest interface or API from my home connection.

Some of my colleagues can download correctly from their home. And I can download it very well from a server.

So I know that the problem is not my wordpress sites, it is my home connection. Still, I have literally never had a problem with other sites that I have used for years. Not a single problem. With the exception of this wordpress problem, which has been going on for as long as I have this internet connection.

How can I debug / fix the problem? Via Chrome, in the development tool network, demand wp-admin/async-upload.php just hold. No response, no error, no byte transferred. Through the rest API in node.js, I get either write EPIPE or read ECONNRESET

networking – Firewall: is an incoming rule required to obtain SYN-ACK from the server when the outgoing rule is already there?

I have a VPC, in which I have an EC2 instance deployed in a private subnet.

I have my NACL (subnet firewall) ALLOW ALL on incoming and outgoing calls.

I have my security group rule (Ec2 firewall), it blocks the public ip on the incoming rule and allows the public world on the outgoing rule.

Now my EC2 instance establishes a connection with the call provider (twilio) and initiates a call and it succeeds.

From my ec2 application, it initiates a three-way handshake, since my outgoing rule is ALLOW everything it reaches twilio via NAT. The packet will be like (the source IP: is the NAT IP and the random port number and the destination IP: is the twilio IP and the port number listening service)

The twilio then accepts the requests and provides the SYN-ACK response to the ec2 server. Now the packet will be (source IP: twilio ip and random port number and destination IP: is NAT IP and the port number of the Ec2 instance is (source-initiated random port number ec2).)

Now my question is, even if the incoming rule does not allow the twilio IP address, how did the three-way handshake work?

networking – Prevent Chrome from verifying a working Internet connection

My configuration:

I have a web server accessible via a WIFI access point, but the server is otherwise completely offline. It simply gives access to the locally hosted website.

Clients obtain their IP addresses and the DNS server (which is the local server) via DHCP. The server itself resolves a specific domain on the local web server (for example, ->

The client connects very well, but when I enter the URL in Google Chrome, it immediately indicates that there is no internet connection (which is true, but the & # 39; 39; URL must be accessible anyway). After about 10 seconds, the page loads as it should. When I reload the site, it appears immediately. Safari on MacOS and iOS does not show this behavior.

So my question is this: why and how does Google Chrome check if a working internet connection is available? Is there any way to prevent Chrome from doing this, in order to immediately access the website and not have to wait 10 seconds?

Networking – Need for a Live Chat Outsourcing Service

With the advent of technology to the world, the world has become tech savvy and people are now spending more time with gadgets. The market has gradually entered the mobile phone via social media advertising. The websites thus formed aim to give a personal touch to the customers by introducing live chat agents who are ready to help the customers by solving all their problems. They are interactive and get along well with customer questions.
The live chat outsourcing service is a new concept that has been widely accepted by customers. A secure feeling is what the consumer exposes after communicating with live chat operators. The availability of operators 24/7 is the most relaxing aspect from which a consumer benefits since he does not have to wait until the morning to open his stores. In addition, the live chat outsourcing service allows you to:
Increase your business sales
Generate more and more leads
Discover customers' pain points
Provide higher customer satisfaction
Increase customer engagement
Increase ORM
Reduce your expenses
Faster problem solving
By using live chat outsourcing, you can connect with your customer base in one of the channels they prefer and use it to deliver a memorable experience with your business. In addition, the live chat outsourcing service has many advantages, as it will reduce support costs and increase the average value of orders and overall sales. So go for the live chat service and win a win-win situation.
To learn more about the live chat service provider, visit the website

networking – Firefox has disabled local directory listings

I want to open certain files in a browser tab in Firefox.

When I access a path like C: Folder, I get "Problem loading the page" when my permissions are all right. I can access


It says:

Access to the file was denied
It may have been deleted, moved or the file permissions may prevent access.

Is there a parameter to change this or an option in about: config?

Networking – Translate the IP address on the router

I don't know if this is possible, and if it is possible, it is surely frowned upon, but … is it possible to perform dynamic translation of an IP address on a router Cisco 3650 L3?

Here is the scenario:

  • Several clients exist on the to subnets.
  • The clients transmit data to the server.
  • The server IP address will change to
  • Clients must continue to transfer data to the server, but the server's IP setting cannot be changed on the client (i.e. clients will continue to send data at 10.101. 0.1 / 24).
  • Routing between these three networks is done by a Cisco 3650 L3 router.
  • Customers have not configured DNS.
  • Basically, the client settings cannot change.

I think there may be some funky layer three magic that could happen at the Cisco switch that would allow dynamic translation between and so that customers can keep sending data to server without modifying any client settings.

Is this scenario possible? If so, what specific Cisco configuration would be required and what strange disadvantages / ramifications could be expected?

Networking – Cannot use apt or ssh inside the Ubuntu virtual machine with the adapter bridged

The host is Windows 10, the guest is Peppermint 10.


I am trying to use a network separate from the host on the guest virtual machine, so that they do not interact. On the Windows 10 host there are 3 visible adapters, built-in LAN, Wi-Fi and the wired USB adapter for connection sharing from an Android phone, shown as "Ethernet 2 " on this image.

In VirtualBox, I defined the network connection as "bridged adapter" and chose the device "based on remote NDIS …", which works great for accessing regular websites (that is, – say I am writing this question from the virtual machine). Verification of the external IP address reported in the virtual machine is different from that of the host, but it is also not the same as that reported by the device that is it 39; attach (for example, the phone says, the virtual machine says, the host says The phone + VM are both on, so I guess it's on the side of the network created by the phone, which is fine as long as it doesn't go through the network of l & # 39; host. This is the guest login.

If I put the network in NAT in the VirtualBox parameters, apt and ssh work well – however, this leads the VM to share the host's IP.


Everything works as expected except the attempt to update via apt and the attempt to ssh to another remote machine (VPS). I can easily switch from the phone to the VPS, but not from the virtual machine that shares the same connection. I can ping addresses listed as inaccessible by apt with 0% packet loss. With ssh, all connections fail with "Connection timed out" (executed with -vvv, no other errors or messages except resolution, reading configuration, then connection).

I guess it's definitely a configuration / security issue somewhere, but the fact that everything else seems to be working fine is the reason I'm completely confused. Extensive research has led me to verify that the MAC address of the bridged network is the same in vbox and the guest, and that IPv6 may also be an issue but the addresses do not appear to be IPv6, so I'm not sure if this applies – most of the other threads seem to have no connection with a bridged adapter, which doesn't seem to be the problem in my case. I'm sure other things could also be broken, but apt / ssh are the only ones I have come across and I honestly can't find any indication of what they're doing that everything else is not.

Networking – Connect to RDS via a pairing connection via a private VPC

Here is my situation:

  • RDS in VPC-A and AWS-account-A
  • Server1 in VPC-B, AWS-account-B and is a private network only
  • Server2 in VPC-B, AWS-account-B and is on the public network (eth0) and the private network (eth1)

the private network subnet is

the public network subnet is

I have successfully established a pairing connection between the VPC-A network ( and the VPC-B private network. I have checked and I can connect from Server1 to RDS successfully.

There is a network connection between Server1 and Server2 working. Basically, Server2 has two network interfaces and eth1 is on the private network.

My problem is that I can't run it from Server2, for some reason there is a network problem.

from Server2 (I added a route for the RDS network:

$ route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface         UG    0      0        0 eth0   U     0      0        0 eth0   U     0      0        0 eth1     U     0      0        0 eth1

but traceroute shows that it is not accessible:

$ traceroute
traceroute to (, 30 hops max, 60 byte packets
 1 (  2998.396 ms !H  2998.376 ms !H  2998.372 ms !H


$ ping
PING ( 56(84) bytes of data.
64 bytes from icmp_seq=1 ttl=64 time=0.351 ms
64 bytes from icmp_seq=2 ttl=64 time=0.365 ms

What am I missing?

networking – Access the bridged subnet

I would like to use ISP2 instead of ISP1 Internet from PC1 computer. But I can't even ping the antenna Ahowever, antenna B shows that it is connected to antenna A. I would also like to access all devices on the 192.168.1.x subnet and vice versa. What am I missing?

Antenna A and B antenna configuration