Trying to understand router slot/port designation and slot/port.subinterface designation

I understand slots and port designations.
but I don't understand slot/port.subinterface designations.
What are they for?
brothertruffle880Asked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

naderzCommented:
It's best to explain using an example. Do you have an example that you would like to review?
0
kevinhsiehCommented:
Sub interface would normally be for a vlan on a trunk port. Each vlan would have its own sub interface.
0
brothertruffle880Author Commented:
I'm drawing a visio diagram for someone and I see notations for sub interfaces.  I know nothing about them whatsoever.  The reason for my posting the question was:  I wanted to educate myself about them.  I know about routers and switches but my knowledge is quite dated (back to the 1990's)
0
Big Business Goals? Which KPIs Will Help You

The most successful MSPs rely on metrics – known as key performance indicators (KPIs) – for making informed decisions that help their businesses thrive, rather than just survive. This eBook provides an overview of the most important KPIs used by top MSPs.

naderzCommented:
A sub-interface allows you to make one interface (Ethernet, Serial, Etc.) look and behave like multiple independent interfaces.

So, when you have Interface FastEthernet 0/1.1 and FastEthernet 0/1.2 you have essentially created two interfaces out of one. Each interface can have its own IP address, Access Lists, etc.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
AkinsdNetwork AdministratorCommented:
A common terminology for this is "Router-On-A-Stick"
This has multiple advantages but all are centered on apparently making 1 "port" appear as many "ports".
Popular with WAN links, ISPs etc
0
brothertruffle880Author Commented:
naderz:  So how do you address each of the interfaces?  If one interface can create multiple interfaces out of one, how do you differentiate or address the two different interfaces?
0
kevinhsiehCommented:
Say you have interface FastEthernet0/1. A sub interface would then be FastEthernet0/1.1, FastEthernet0/1.2, FastEthernet0/1.3, etc.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Network Architecture

From novice to tech pro — start learning today.