3. Fundamentals of WAN Flashcards
What are different names for a leased line
Serial Link Point to point T1 WAN link Private line
What are the two most used datalink protocols for leased lines1
HDLC
PPP
What does HDLC stand for
High-Level Data Link Control
What does PPP stand for
Point to Point Protocol
What are the parts of the HDLC headers and compare them to an Ethernet frame
Flag - Preamble/SFD Address - Destination MAC Control - N/A - no longer used today Type - Type FCS - FCS
Draw an HDLC frame
Flag 1 byte | Address 1 byte| Control 1 byte | Type 2byte | Data (variable) | FCS 2 byte
What is in a Cisco HDLC frame that’s different from ISO HDLC
Type
What are disadvantages with Leased Lines
higher cost
longer lead times to get service installed
slower compared to today’s standards (10Mbps)
What is the router on a customer’s site called
Customer Premise Equipment (CPE)
Where does the customer’s CPE connect to on the telco side
Telco switch
What are different names for Ethernet WAN
Ethernet Line Service (E-Line)
Ethernet emulation
Ethernet over MPLS (EoMPLS)
What kind of connections are used in lease lines
serial connections
Where does a customer’s router connect to
Service Provider Point of Presence (PoP)
What is the focus of Internet Protocol (IP)
Routing data in the form of IP packets form source host to destination host
What is the size of a IPv4 header
20 Bytes
What are the general steps for routing protocols to learn routes
- Each router adds a route to its routing table for each subnet directly connected.
- Each router’s routing protocol tells its neighbors about the routes in its routing table including directly connected routes and routes learned from other routers
- After learning new route from neighbor, it adds route to its IP table with neighbor as next hop
What are the two parts to ARP
ARP Request
ARP Reply
What are the 2 foundantional rules of subnetting
- Two IP addresses not separated by a router must be in the same subnet
- Two IP addresses separated from each other by at least one router must be in different subnets
What is the size of an IPv4 address
32 bits
What are the 2 foundational rules of subnetting
- Two IP addresses not separated by a router must be in the same subnet
- Two IP addresses separated from each other by at least one router must be in different subnets
What is a routing protocol
Protocol used by routers to build routes and maintain routing table
