Watched this one during lunch today, I thought This was a good way to explain Network behavor.

I'd like to think of "L3 switch" as being short for switch with layer 3 functions.
Often they are used for routing traffic between VLANs. A router can do that as well but a L3 switch can usually do faster and on more ports at the same time.

Typical is to have a bunch of L2 switches where the end points connect and then the L2 switches are uplinked to one L3 switch that takes care connecting the L2 switches together and do inter-VLAN routing.

There are also L3 Lite switches (aka L2+) which are L2 switches with a limited L3 functionality like for instance static routing.

L3 switches are usually the ones with the most features in all categories so sometimes you need to buy a L3 switch because you are after some other feature, like redundant power or what not.

In small networks L3 switches are usually not needed.

As an example Dell's PowerSwitches for instance are managed switches for building out the network to end points (campus).

They are like this:

N1100 series - L2 switch N1500 series - L3 Lite switch N2000, N3000 series - L3 switch

They have the same OS and work the same but each step up in the series gives you more features and more speed and higher cost.

this is amazingly didactical... really enjoy this.

This video was a great introduction to networks. I like the description of the moving truck, it gives an image to start.

@brianwinkelmann said in Windows Firewall with Advanced Security - CompTIA A+ 220-1002 Prof Messer:

what about the Windows Defender, I mean the antivirus and the firewall of Windows They go hand in hand right?

They go together as in they are both security components of the Windows operating system. But that's about the extent of it. They are both very good, they should both always be used, they are both for the purpose of security. But they are not actually associated other than in name.

Useful tools for networking!

Issue was fixed. Enclosure back plane was bad. A new C7000 had to be purchased and swapped out and it worked right away.

I remember when sometimes I used some of the network tools mentioned on this video, also making my own RJ45 cable connection for first time.

@scottalanmiller said in Internet Connection Types - CompTIA A+ 220-1001 Prof Messer:

Satellites were launched last week

f3dba3be-8a5f-415b-a2bc-0a7043c71d98-image.png

@scottalanmiller said in Internet Connection Types - CompTIA A+ 220-1001 Prof Messer:

Satellites were launched last week that should be a total global game changer.

Those 60 are not going to do that. They do not have the point to point lasers for relay. These are all still engineering tests that have to relay all communications through ground stations.

@scottalanmiller said in Using IP Addresses - CompTIA A+ 220-1001 Prof Messer:

@connorsoliver said in Using IP Addresses - CompTIA A+ 220-1001 Prof Messer:

When using an SSL VPN, if the VPN concentrator decrypts the data being sent, wouldn't it be possible for someone to capture the data and also decrypt it?

Possible, sure. But very, very hard. The VPN concentrator has the keys, someone intercepting the traffic presumably does not. The point of VPN encryption is to make it so hard to decrypt the data that you don't care if they see it. It's about making something safe enough that we assume we will send it in the open and not worry.

So we assume that people capture that data constantly - but we have made it so hard to use, that they can't do it.

We more than assume that - we pretty much know the NSA is doing that after the Snowden leaks.

Cool very interesting!

taking a few mins to watch this!

@scottalanmiller said in Network Services - CompTIA A+ 220-1001 Prof Messer:

@valentina said in Network Services - CompTIA A+ 220-1001 Prof Messer:

are proxy servers used for security purposes? do they have other functions?

Yes, very much so.

They are also very commonly used to allow a single IP address to be used for many services. The most common example... a single proxy server with a single (expensive) public IP address can handle requests for hundreds of thousands, or even millions, of websites. Behind the proxy server can be one or one million separate web servers each serving out applications or web sites or whatever and the proxy server can look at the incoming request and determine, based on the URL used, which server and port to send the request to behind itself.

Because of the above, they are often used for load balancing because they can send requests to different servers for the same application or site.

Proxy servers often have caches in them, too. So they quite often store simple, static information "at the edge" to deliver it faster while the application servers behind them do the heavy work for database requests and stuff.

Proxy servers are sometimes used to "hide" the true location of a server. Cloudflare famously does this so that attackers have no idea where a web site actually comes from, all they see is Cloudflare's proxies.

A proxy can also do things like handle SSL security so that web servers behind it (or other servers, proxy doesn't imply web) don't have to do that work, as well.

Hrm, I only have around 20 subdomains pointing to the same IP so far. If my home lab box was a little beefier I'd take this as a challenge. (Scott might as well be describing my home lab environment here.)

Interesting

@Osvaldo said in Wireless Network Technologies - CompTIA A+ 220-1001 Prof Messer:

I wonder if there is a tool for radio hacking zigbee?

Many of the devices that use the protocol are never updated, therefor quite a large target for hacking.

The radio protocol itself I doubt is much use to "hack" (Any cheap software defined radio will be able to imitate a Zigbee device.)

I made this safe for work

test.png

Done with this one!

@Dashrender said in Installing a SOHO Network - CompTIA A+ 220-1001 Prof Messer:

@scottalanmiller said in Installing a SOHO Network - CompTIA A+ 220-1001 Prof Messer:

@Dashrender said in Installing a SOHO Network - CompTIA A+ 220-1001 Prof Messer:

@scottalanmiller said in Installing a SOHO Network - CompTIA A+ 220-1001 Prof Messer:

Think about a thermostat that you can connect to online. The thermostat IoT device is in your home. The IoT vendor has a server. You work with the thermostat through the hosted server somewhere. If that server was compromised, bad guys could run up your AC bill.

To bad most cameras don't work that way - instead they use uPNP to open ports and just spew your video feeds to the world.
https://www.insecam.org/

"Most" of anything is crap. No good camera does that. What a bizarre system.

Agreed - but it's very likely type of equipment they'll run into out in the wild.

I've never seen that with a client in the wild. I'm sure it happens, but it's not something we really run into. Common with home users, for sure. As business class routers don't allow that, it limits it in the field a lot.

And it's not like we don't see cameras, worked with a security company just today!

Also, lots of customers on cheaper or less "business" equipment often have double NAT which while awful, stops UPnP.

Done with this one too! Reading the comment section : - )