## Can you enter the Schengen area with a residency visa from another country?

No, since Ireland, Romania, Croatia, Bulgaria and Cyprus do not fully implement the Schengen acquis and are therefore not considered a Contracting Party.

The Schengen Border Code uses the term Member States, but doesn’t define exactly what that means.

Since family members of EU-Citizens may require a Schengen Visa, when they reside in a non-Schengen EU Member state, to enter the Schengen Area, one can assume that Member States of the Schengen acquis. is meant.

Article 21(1) of the The Schengen acquis – Convention implementing the Schengen Agreement of 14 June 1985…: Aliens who hold valid residence permits issued by one of the Contracting Parties may, on the basis of that permit and a valid travel document, move freely for up to three months within the territories of the other Contracting Parties, provided that they fulfil the entry conditions referred to in Article 5(1)(a), (c) and (e) and are not on the national list of alerts of the Contracting Party concerned.

## networking – Trying to PenTest my client’s local network but their Public IP is the same as other people in the area

I posted something similar before and it was just Closed due to clarity. So I’ve updated it and added clarity and changed the title.

I had posted on Stack’s Network Engineering but apparently I was not smart enough so they told me to come to SuperUser but maybe I’m not even smart enough for here, considering my previous question was just closed and not left open for comment.

Plus, it said I could edit my question but…it still seems to be closed to any comments.
Why is my WAN/Public IP the same as my neighbor’s? Trying to PenTest

EDIT— I am using established PenTest scenarios that might be used by a hacker to get into a network. With all of the ransomware problems I worry that they might target my client. I tried posting this on Network Engineering, since I’m trying to lock down a business client’s network.

The problem I’m encountering is that IF the ISP is using CGN, is there a way to circumvent that? As I mention below, I imagine that a proficient hacker can get around that in some way.

The main question is, how do you PenTest a network under these circumstances? Apparently this is too basic for Network Engineering so they sent me here. So let’s assume I’m trying to be a SuperUser but I’m not there yet, where do I start? It doesn’t really help to just close my post, asking for more detail. I feel I provided enough detail for this situation. Is there a NotSuperUser site I should go to? I’ve already been downgraded from Network Engineering to SuperUser and now you are saying my question isn’t even valid here.

Please tell me what other site I can go to for help if you can’t help me here. Or tell me how much more detail I need to provide. I already said I can’t PenTest a router because it has the same IP as every other router in the area likely due to the ISP using CGN. But it still needs to be tested. There must be a way to test these networks. The fact that we have to test these networks means that all the things that are in place are not secure, including CGN.

I didn’t want to mention this because I felt it was an issue with ISP and not relevant to this discussion, but… I did a test on the “Public IP” and it indicated vulnerabilities, mainly lighthttpd. That’s not likely a problem on my client’s router. But, because I can’t test my client’s router specifically I don’t know for sure. I have contacted the ISP but they only work M-F. But the point is, I need to test my client’s router for problems, outside of the ISP. That was my question, how to test a router hidden behind a CGN, if possible.

I hope that was enough clarification. —EDIT

Hello and thank you in advance for any assistance. I’m new to this side of Stack. I tried posting this in Network Engineering but even thought I’m working on a commercial client’s network it was off-topic and they suggested I post here.

To start, I was wanting to do some Penetration Testing for a client. The client is a small office, not a home network. I’m starting with some very basic things. The most basic is pentest-tools website. I wanted to start by testing this at home because their network it not like some Google corporate network. The use off the shelf hardware. But today when I went to get their “Public/WAN” IP address, so that after I’d tested my own network I could test theirs remotely. What I found, using whatismyip, is that we both have the same public address.

I did read a few articles about CGN on NE and that is likely the case for me. (from this article here. https://networkengineering.stackexchange.com/questions/30184/is-my-dynamic-ip-address-provided-by-my-isp-shared ) I tried using the tool listed but it is a bit outdated.

My tracert shows this at the beginning. The public IP I get does start with 98.163 but it is not the same as the one shown in tracert. When I do ipconfig, in Windows, my gateway is the first hop here.

``````  1     1 ms    <1 ms    <1 ms  192.168.1.1
2     1 ms     1 ms     1 ms  192.168.10.1
3     5 ms     4 ms     3 ms  10.4.x.254
4     6 ms     4 ms     6 ms  98.163.xx.x
``````

My first concern is, how do I PenTest their local network remotely, or basically as if I were a hacker, if I can’t get to their router directly, or is this not something I should not worry about with CGN? ie, it’s not even possible to do and I should just worry about someone who gets onto their local network using a provided WiFi access code. I really can’t imagine that is the case for an experienced hacker, they must know their way around CGN.

Regards, Dewi

## Can Brazil residence permit holder enter Schengen area without visa?

Citizens of Brazil can enter the area visa free (90 days within a 180-day period). But not sure about residents of Brazil.

If you don’t know the answer, you can reply for Argentina or Mexico since I believe they have similar policies.

## mg.metric geometry – A circle with radius R, find the total area of all the circles added together

A circle with radius R is shown below in figure a. In figure b, two circles with a radius of 1/2 R are placed on top of the original circle from figure a. In figure c, four circles with a radius of 1/4 R are placed on top of the circles from figure b.

The image

Assuming this pattern continues indefinitely, find the total area of all the circles added together.

(With steps would be wonderful, I really don’t understand)

## geometry – Minimum area binding box for set of points

I am writing some paper and stuck at proving that in min area binding box there needs to be 2 points on the edge of min square. Every single time I make a new case I got that. By getting extreme points of that set and making lines trough them there must be one on corner, but is there any formal proof to support that?

## algorithms – Finding the distance from a point to a \$R^m\$ restricted area in \$R^n\$

The problem is described below:

When m=2 and n=3, it is basically finding the distance between a point and a line segment in $$R^3$$.

But when both m and n are larger, do I have to use a generic optimizer to solve this, or this problem can be precisely solved with mathematics, like the case when m=2 and n=3?

What I have done for now:

Approach A:

I tried to solve it with Gram–Schmidt process and projection but got stuck.

For example, the following R code:

``````P <- c(1,1,1,1)

m <- rbind(c(1,-1,1,2)*1/3,c(1,2,1,1)*1/5)

m2 <- qr.Q(qr(t(m)))

P2 <- P%*%m2(,1)*m2(,1)+P%*%m2(,2)*m2(,2)
``````

It does not take into account the restriction $$w_1+w_2=1$$

Approach B:

Tried to solve it with lagrangian optimization, but also got stuck there.

## Length of Tubing required in a rectangular area

I have a rectangular area of 170cm x 540cm and I would like to fill it with tubing of diameter 16cm. I need to calculate the approximate Max length of tubing I need to buy if I am going to fill the maximum area. I assume the best thing would to wind the tubing around in an elongated spiral fashion. Can you help me ?

## Sou novo na Área de shell-scripts, eu estou na dúvida de como fazer e como começar esse programa

Queria saber como fazer esse script.Crie um programa onde você passa o nome do usuário como argumento. Se passar 2
nomes, você deveria imprimir os 2 nomes. Se passar mais do que 2 argumentos, você
deveria imprimir uma mensagem: “Apenas 2 nomes são permitidos. Tente de novo!”,
e saia do programa.
Queria como eu passaria esses argumentos.

## focal length – Is x50 zoom camera able to zoom 500 meter target area from a 6 km distance?

I have a x50 zoom camera and here is some specs of the camera and lens:

• Focal length: 6 mm ~ 300 mm
• Field of view: 58.4° ~ 1.4°
• Resolution: 2 MP

I drew a scheme to explain my question properly, you can see below:

I have a 500 meter diameter circle area 6 km distance to my camera. My question is that is this camera able to zoom to this target area or not ? Can we calculate this with these camera specs ? If yes how ?

Thank you all.

## sensor – Capturing Lightning with Pi Camera – Hard purple lines in overexposed area

Can I fix the purple lines in this image in capture processing on my Pi HQ Camera?

When shooting long exposures at night, my Pi HQ Camera has purple line artefacts where the lightning strikes, or there is extreme over exposure. This is not something I can avoid, as I do not know if there is lightning and ideally, the sensor processing would better handle this. The sensor in question is a Sony IMX477 sensor and the software controls for night exposures are manual shutter speed, digital and analogue gain settings.

For reference, please see the example image (of which I have many more). A one-off could be repaired without too much fuss, but having dozens is a pain.