Wide Area Networks Flashcards
What are three WAN topologies
Point to Point Network, Hub & Spoke Network, Full Mesh Networks
What does single/dual and homed/multihomed represent
Single/dual = 1/2 or more connections, homed/multihomed = 1/2 or more ISPs
Tell me about Border Gateway Protocol
Path Vector routing protocols, uses path attributes to select path,
What is MPLS
Multiprotocol Layer Switching - Assigns labels to packets and the MPLS cloud makes forwarding decisions based on the labels (instead of ip)
How does MPLS encapsulate its label
Label is 20 bits and inserted between Layer 2 Header and Layer 3 header in a packet
What is the GRE Tunnel Theory
Generic routing encapsulation tunnel, a type of tunnel that can encapsulate multiple layer 3 protocols (single hop) GRE tunnel doesn’t have security but IPsec can do those things
What is a multipoint GRE
allows a single router interface to have multiple GRE tunnels
What is PPP
Layer 2 encapsulation used on leased lines, supports authentication, compression, error checking & connection, logical multilink
What is PAP, CHAP, and how are they different
PAP sends password over in clear text while CHAP sends password hashed up
What is LCP
Link control protocol, protocol used by PPP to setup, maintain, and tear down a connection
What is NCP
Network control protocol, protocol used to negotiate the configuration of protocols over a PPP link (whether that be ip, cdp, etc)
What is PPPoE
PPP over ethernet, carries 8 byte header within ethernet frame, commonly used with DSL client and Service Provider connections
What is the default encapsulation of an interface
HDLC, High Level Data Link Control Protocol
What side has the clocking, DCE or DTE
Data Circuit Terminating Equipment or DCE
What type of routing protocol is EIGRP
Advanced distance vector, as is RIP
What type of routing protocol is BGP
path vector routing protocol
How does BGP choose a route
Weight - BGP likes the path with the highest weight, Local preference - BGP selects the one with highest local preference value, Aggregate preferred over network, Shortest AS_Path is used as a tie breaker
What’s the flow of a packet through a MPLS system
Customer Premise Equipment CPE connects to MPLS Cloud, Edge Label Switch Router adds label to packet, LSR or Label Switch Routers with MPLS forward based on labels
What is a DMVPN
Dynamic Multipoint VPN, allows for a DMVPN tunnel to be created between two hosts
What is the Next Hop Resolution Protocol
Allows the interface at one end of the GRE tunnel to discover the IP address of the device at the other end of the tunnel
What is the administrative distance of a connected interface
0
What is the administrative distance of a static route
1
What is the administrative distance of external BGP
20
What is the administrative distance of Internal EIGRP
90
