Q: WAN Basics

 In 200-301 V1 Ch03: Intro Routing, WAN, CCENT-OLD, Q&A

WAN connections span much longer distances than LANs – so what happens in that WAN? Even for CCENT and CCNA, you can understand some of the basic facts about how a WAN service provider builds a WAN connection. This next sample question asks about just that.

The Question

Both sites shown in the figure have a small number of devices located on one floor of a single building. The sites, a few hundred miles apart, connect with an Ethernet WAN service. Which are accurate when comparing the Ethernet LANs and WAN in this small network?

A) The data link frame that crosses the WAN uses the PCs’ MAC addresses

B) The WAN physical link likely uses fiber optic cabling

C) The WAN physical link likely uses UTP copper cabling

D) The WAN link uses a header that combines HDLC and Ethernet


Figure 1: Figure Reference


Answer Post in a Few Days!

I’ll post an answer post in a few days. Watch for it! It should be the next post in chronological order as well, so watch for the link at the bottom of this page (just above the comments section).

A: LAN Broadcasts
A: WAN Basics
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A) is incorrect. It uses the Gigabit MAC address in the Routers.

B) Is correct. These long distances require Fiber Optic

C) Is incorrect. UTP distances are limited to some meters.

D) Incorrect. The Header is only ethernet


B) The WAN physical link likely uses fiber optic cabling

Punya Atma

The answer is B, because the distance between the two sites, is said, a few hundred miles, so the right option, fibre.

The data link frame which crosses the WAN, not uses the PCs’ mac addresses, but, the routers’ mac addresses.
The WAN link uses only the Ethernet header, but not a combination of HDLC and Ethernet headers.
UTP cable not used here as the correct answer of this question simply knocked down that option.



Please correct me if I’m wrong, but shouldn’t the sentence “WAN connections span much longer distances than WANs” be “WAN connections span much longer distances than LANs”? So shouldn’t the last word be LAN instead of WAN? Because in its original version, the sentence compares the same thing to itself (WAN with WANs).

Have a nice day.
Best regards,

Wendell Odom

Doh! Yep, silly me. Thanks, Attila! All fixed now.


B) The WAN physical link likely uses fiber optic cabling

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