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How to retrieve a device name from IP or MAC on LAN

In Visual Studio 2015, VB, in Windows 10, I have a small program where I use the arp -a command
to pick up the mac and I/P addresses of connected devices on my lan. From everything I've read (and tried), the answer
somehow comes back to DNS.getHostEntry which throws a No Such Host when fed a cell's I/P and
I understand that, a cell phone is not a host. Does anyone know of the appropriate DNS or other type
command that, fed an I/P or MAC will return the device's name?

Thank you.

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Mixing broadband packages

Sorry, but my question requires a long-winded explanation. Because of where we live, my wife and I cannot get decent broadband except through a satellite package which recently went down for two days. It leaves us totally isolated since the phone is also satellite and we get no mobile reception here either. So calling any technical support or anyone is almost impossible!! So we will get a landline installed but the basic broadband costs only marginally more and would be useful as back up when the satellite package goes down, though it's only 1- 5 Mb/s instead of 45 Mb/s. Rather than use wireless both my wife and I connect to our computers through Home Plugs which work well for us. My question is this. If both the landline broadband and satellite broadband are connected to a homeplug, what will I get when I connect my computer to my homeplug . . . a scrabbled mess or two distinct LAN connections that I can choose at random?

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Issues with AppSec

To understand the current and future state of application security, we obtained insights from five IT executives. We asked them, “What are the most common issues you see with application security?” Here’s what they told us: 

  • Two issues are the human attention span and the accuracy of automated systems. People who monitor or engage with security need to focus time and effort on things that matter and produce outcomes that serve a purpose. They cannot do that without accuracy, and accuracy comes from application-insight. The other is automation systems, where simply sending data is not helpful. Data must be relevant, with enough metadata to properly act. This relevance is tied to the application's insight.
  • There are so many guidelines right now. Authenticity, authorization, encryption, and availability mechanism – ensure all four are done with discipline and automation. Do the fundamentals well on APIs and mobile and modern web to avoid the majority of data breaches. When security hooks up with DevOps, it’s an impedance mismatch that causes a lot of friction.
  • The most common issue I see is doing nothing to secure your applications, followed closely by taking too narrow an approach to application security (for example, looking at security from only one perspective, such as static code analysis) and falling prey to a false sense of security. I don’t have the data to identify which is the largest actual risk based on break-ins, but I wouldn’t be surprised if the latter point is more critical.
  • We commonly see applications that are designed with security principles in mind but not from a network perspective. How an application acts on a single node in a network is different from how it behaves as it traverses the LAN and WAN. Our solution helps customers keep applications secure as they traverse networks, both local and wide-area.
  • Don’t use tools. AppSec testing technology today can come as a tool or a cloud service. Technology emerges first as a tool you learn to use, run, and be responsible for its accuracy and breadth. The next wave is when the technology is delivered as a cloud service. Now, we have more services than tools. Adopt technologies like cloud services rather than tools. Delegate AppSec to third-party vendors operating at high scale in the cloud.

Here’s who shared their insights:

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Odd CraigsList Issue

Greetings,

Okay, so having an odd issue with a network at work. This is a fairly small LAN with about 30-50 workstations / devices / printers / etc. So the issue in essence is that only one of the workstation on the network can access craigslist. All others time out.

This is not a DNS issue as a ping to craigslist.org resolves correctly to 208.82.237.226 on all workstations. Also a tracert completes on all workstations with nothing remarkable.

I have only seen this once before and the issue was never resolved.

This is not an ISP issue as one of the workstations can connect and browse Craigslist without issue. Also one of the workstations that is unable to connect from the LAN was able to connect when direclty linked to the ISP modem.

Okay, so that points to an issue with one of the routers or perhaps a switch.

And to add to the confusion.... All of the workstations that "time out" DO receive a cookie from Craigslist. The cookie, 'cl_b' is one of the same cookies that the workstation that CAN connect also receives.

Let me also add that this issue of timing out is ONLY happening with Craigslist. No other sites have this issue.

The basic topology of the network is: Cable Modem (in bridge mode) -> Bridged PFSENSE Router v2.4.3-RELEASE-p1 -> Zyxel Switch (GS1900) -> TPLink Router (TL-R470T+) -> HP Switch (Procurve 2824) -> Worstations / Printers / AP's / Etc.
The reason for the two routers are servers that are wired to first switch with external IP addresses. The first router acts as a firewall / IDS / IPS. Router two does limited NAT.

I have scoured logs of the switches and routers. I have also done a packet capture from one of the afflicted workstations, please see attachment. It's not browser specific as the problem exists with all browsers with the exception of TOR browser, but we all know whay that is. This isn't a firewall / AV issue as all have been disabled during testing.

Any help in this matter would be greatly appreciated. I am stumped. If this were a home issue I could probably just replace the router with a different device, but honestly I would like not only a solution, but an understanding of why this is occuring. What makes Craigslist different than all other sites? What makes the one workstation that can connect different than the others?

Thanks