Yes, #IPv4 is the legacy Internet protocol, but unfortunately we're facing a long period of dual-stack networks and #subnetting is still a thing. In his #deepdive Kevin Wallace explained it in a simple way with easy hints to remember. https://youtu.be/vY4cjGpRiIs

#CIDR Notation vs #Subnet Size
#networking #subnetting

Hier ein kleiner Ausschnitt aus meinem neuen Video zum Thema #Subnetting :) https://youtu.be/jgwWFKryrOw

Cisco has long since retired the CCENT certification but if I were a hiring manager and a candidate had only that one cert under their belt I'd hire them immediately. That knowledge proves one can learn and move forward in a career. #Subnetting #CCENT #ICND1 #Certification #EntryLevelNetworking #SkillSet

Old subnetting notes I had to dig up and refresh on while studying tonight. Enjoy!

Subnetting:

The representations of IP’s and prefixes (our masks) exist for each range. Whenever we see a /8, /16, or /24, the /number is a prefix, so 10.10.10.1 /24 is an address with a prefix. The classes listed for IPv4 aren't actually too scary when you space out exactly what is going on.

Let’s say we have a 255.255.255.0 mask

Try to look at it this way: Class A is X.Y.Y.Y Y being the hosts by number

If we have a /24 and need to understand how this translates:

255.255.255.0 is the value we end up with because the binary equivalent to 255 is 11111111

If we do this for every portion of our mask we get:

11111111.11111111.11111111.00000000

We end up with /24 because we are counting each set of 1's (11111111 + 11111111 + 11111111 = 24).

All we're essentially doing here when we subnet is counting the bits and looking at a mask.
If you look at it this way then the 2^n-2 formula makes a lot more sense and becomes clearer.

What would be a /26 ? 11111111.11111111.11111111.11000000 or 24 +2

We added 2 bits to the sum we had when we converted and if we convert 11000000 again, we get 192 as a number. Then we subtract.

** Resources:**
https://subnetting.org

https://www.youtube.com/watch?v=ZxAwQB8TZsM

Thema Broadcastdomäne. Es geht um Performance Einbußen bei der Vernetzung mehrerer Subnetze über Layer 2 Switches im Vergleich zu einer sauberen Trennung (ein Switch, ein Subnetz oder eben port- / tagbasiertes VLAN). Bin auf der Suche nach Informationen zu diesem Thema, vor allem nach einer Gegenüberstellung aus der klar hervorgeht dass die Performance stark darunter leidet (Broadcasts und Netzlast). Vom Sicherheitsaspekt mal völlig abgesehen. Würde mich freuen. VG #IT #Subnetting #Broadcast

#Network #Subnetting

#Networking #Subnet #IPv4 #CIDR #CheatSheet