Ch. 4 - Network Layer (Data Plane) Flashcards
What are the key functions of the data plane and the control plane?
Data plane = forwarding - local
Control plane = routing - network-wide
What is a router?
A device that examines header fields in IP datagrams and forwards them between networks.
What are the two control-plane approaches?
Traditional routing algorithms (routers) and
Software-defined networking (SDN) (servers)
What is the difference between forwarding and routing?
In essence, routing is the “brain” that figures out the best path, while forwarding is the “muscle” that moves the packets along that path.
What is the role of a forwarding table within a router?
A router uses a packet’s header to index the forwarding table, which is then used to determine the outgoing link interface.
What is DHCP?
Dynamic Host Configuration Protocol (DHCP) is a network management protocol used to dynamically assign IP addresses to devices on a network.
What is NAT?
Network Address Translation (NAT) is a technique that allows multiple devices on a private network to share a single public IP address.
What is ARP?
Address Resolution Protocol (ARP) is a network communication protocol that translates a computer’s dynamic IP address to its permanent MAC address.
What is HOL blocking? Does it occur in input ports or output ports?
HOL blocking is “Head of the Line” blocking - when a queued datagram at the beginning of a packet prevents others from moving forward. It occurs in input ports
How many IP addresses does a router have?
The router interface has two IP addresses, one public and one private.
What is SDN?
Software-Defined Networking (SDN) - centralized control and configuration management often in public/private cloud
OpenFlow
Protocol for implementing SDN match + action rules.
Quality of Service (QoS)
Guarantees for bandwidth, loss, order, timing.
Best Effort Service Model
No guarantees on delivery, timing, or order of datagrams nor bandwidth available.
Encapsulation
Wrapping data segments into datagrams for transmission.
What is Destination-Based Forwarding?
Forwarding based solely on destination IP address.
What is Input Port Queuing?
Storing datagrams when arrival exceeds processing rate.
What is TCAM?
Ternary Content Addressable Memory (TCAM) is a memory type for fast address retrieval.
What is CIDR?
Classless Inter-Domain Routing (CIDR): A more flexible method using variable-length subnet masks (VLSM).
What is Classful Addressing?
A historical method of dividing IP addresses into classes (A, B, C) based on the first few bits.
Subnetting
Dividing a network into smaller subnetworks to improve network efficiency and security. Uses subnet masks to identify the network and host portions of an IP address.
What are the main differences between IPv4 and IPv6?
IPv4: 32-bit address space, represented in dotted-decimal notation (e.g., 192.168.1.1)
IPv6: 128-bit address space, represented in hexadecimal notation (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334)
Why the switch to IPv6?
Running out of addresses for IPv4 due to the rapid growth of the internet. IPv6 has a vastly larger address space to accommodate future growth.
What is the ARP frame structure?
Hardware Type, Protocol Type, Hardware Address Length, Protocol Address Length, Sender Hardware Address (MAC), Sender Protocol Address (IP), Target Hardware Address (MAC), Target Protocol Address (IP)
