Why is WAN my weakness?

phoeneous

I've been studying icnd2 for about 9 months and I feel clueless to real-world L2 WAN scenarios. So I put together a list of questions that hopefully will clear things up for me. Somewhere along my icnd1 and icnd2 studies, I either missed this information or wasnt paying attention...

1. Whats the main differences between using a serial interace vs an ethernet interface for wan connectivity?

2. When can you and can you not use either a serial or ethernet interface?

3. Which type of interface is best used for: leased line internet connections, dedicated point-to-point, frame relay, mpls?

I know these are basic questions which is why I want to have a firm understanding of them not only for the exam but also for the job.

Thanks

ilcram19-2

phoeneous wrote: »

I've been studying icnd2 for about 9 months and I feel clueless to real-world L2 WAN scenarios. So I put together a list of questions that hopefully will clear things up for me. Somewhere along my icnd1 and icnd2 studies, I either missed this information or wasnt paying attention...

1. Whats the main differences between using a serial interace vs an ethernet interface for wan connectivity?
2. When can you and can you not use either a serial or ethernet interface?

3. Which type of interface is best used for: leased line internet connections, dedicated point-to-point, frame relay, mpls?

I know these are basic questions which is why I want to have a firm understanding of them not only for the exam but also for the job.

Thanks

1.- mainly speed and avaliability
2.- sometimes the only high speeds you can only buy a T1 (serial) or not even that DSL and or clable are also avaliable which if they provide a cable modem or dsl modem you should be able to use and ethernet port on your router.
3.-depends how cheap they are, if they are point to point they can provide you with an ATM or frame relay circuit which you will need and interface and/or a serial interface.
mpls is a whole other story simply because if provides you with a private circuit that most of the time is manage by the ISP
Basicaly it just depends how the ISP give you the connectivity to their network via ethernet or serial port or even a modem.

kryolla

ethernet is the same whether you are getting it from a provider or LAN. Metro-ethernet complications happens at the provider such as VPN and policing. You can usually get a cheaper and faster link via Metro-E than say a serial link like DS3 or OCx. Your limitation is usually your provider and what he offers and of course cost and scalability. Dont think too much into this as a customer.

dynamik

I believe as far as the CCNA is concerned, serial = WAN and ethernet = LAN.

Kaminsky

10mb and above are typically presented to you as ethernet so you just run an ethernet cable from your router's fast ethernet port to the carrier's NTU demarc.

Lower than that, you are typically using 2mb muxes/asdh nodes which typically present on G703 (bnc/rj45 (not ethernet) connectors) or Db15 serial which then connect to wics/aims in your router. These muxes/asdh have a chunk of bandwith supplied to the NTU by carrier fibre and that bw is split across the various ports on the NTU to the size of chunk you want so you can have several circuits from a single carrier device.

ISDN, Kilostreams, standard modems and DSL work over normal PSTN lines and can, except for kilostreams which are db-15 to db60/ss usually, have dedicated connections into the router, sometimes without actually needing a wic as they can be built in to specific types of router. The PSTN signal is just filtered differently for the type of circuit you are getting.

WAN is layer one and two whilst routing protocols are layer three and use that particular WAN method's layer two protocols to route it's layer three traffic across the link. You can use many different routing protocols over wan circuits.

phoeneous

Good info!

A few more questions (at a ccna level)

1. Which wan protocols are only used for internetwork connectivity and NOT internet access?

2. Which wan protocols are only used for internet access and NOT internetwork connectivity.

billscott92787

What resources are you using to prepare?

phoeneous

billscott92787 wrote: »

What resources are you using to prepare?

Cisco press ICND1/2 exam preparation library
Train signal
CBT Nuggets