IP Routing Flashcards
Address Resolution Protocol (ARP)
Translates IP addresses between MAC addresses
Routing
Selecting paths in a network along which to send network traffic
Static Routing
Manually configure routers with specific paths
Describe Static Routing
Simple, but lacks flexibility and scalability
Routing Information Protocol (RIP)
One of the oldest distance vector routing protocols
What is the maximum number of hops for RIP ?
15
Which of the two RIP versions supports subnetting, multicast updates, and simple authentication
RIPv2 (classless)
What environments is RIP suitable for?
Small-to-medium networks with limited scalability and slower convergence
Open Shortest Path First
Link-state routing protocol
What are the key features of OSPF?
Hierarchal design, supports VLSM and CIDR, and updates are only sent when there are changes in the topology
What are the advantages of OSPF ?
Efficient, scalable, flexible, load-balancing, and fault tolerant
What networks is OSPF suitable for?
Large, complex networks
Enhanced Interior Gateway Routing Protocol (EIGRP/Hybrid Protocol)
Enhanced distance vector protocol, combining features of distance vector and link-state protocols
What metrics does EIGRP use?
Bandwidth, delay, load, and reliability
What are the key features of EIGRP?
Supports VLSM and CIDR, sends updates when changes occur, and uses metrics
Describe the advantages of EIGRP
Highly efficient, scalable, and quick convergence
What else can EIGRP provide?
Loop-free paths and load balancing
What network is EIGRP suitable for? What devices are especially suitable for EIGRP?
Medium to large networks especially with Cisco devices
Metric
Value associated with routes to evaluate the cost of path traversal
What value metrics are most desirable?
Lower Values
Border Gateway Protocol
Essential for inter-domain routing on the internet
What does BGP support?
CIDR for efficient IP address allocation
What does BGP employ?
Policies for route selection and advertisement
What protocol is used between BGP peers?
TCP for reliabile communications
Where is BGP crucial?
ISPs and large enterprises with multiple connections to the internet
Describe the characteristics of BGP
Highly flexible and scalable
What can BGP manage?
Large routing tables and complex policies
Route Selection
Determines the best path from source to destination
Which criteria does route selection use?
Administrative distance, prefix length, and metric
Administrative Distance
Metric used by routes to rank the trustworthiness
What do the lower values indicate?
More preferred routes
Prefix Length
Number of continuous bits of the network mask
First-Hop Redundancy Protocol
Used to achieve high availability with multiple physical redundant routers
Hot Standby Router Protocol
Cisco’s proprietary redundancy protocol
Virtual Router Redundancy Protocol
Open standard redundancy
Virtual IP (VIP)
IP address that is not tied to a specific physical network interface
What does VIP provide?
Redundancy and load balancing for services hosted on multiple servers
Where are VIPs commonly used?
Network load balancers and failover configurations
Do several servers share the same IP through VIP?
Yes
Subinterface
It is a virtual interface where the physical interface is divided into multiple logical interfaces
Where are the subinterfaces commonly used? What do they manage?
Where multiple VLANs exist on a router or switch’s single interface to manage various services or protocols
NAT
Translates one IP address to another
What provides NAT?
Router or firewall
What are four advantages of NAT?
Conserve public IPs, no address overlaps with other LANs, easy to connect to the internet, no address renumbering if your network changes
What are the disadvantages of NAT?
Translation delays packet forwarding, loss of end-to-end IP traceability, and some applications do not function with NAT
Static NAT (One-to-one)
One internal address to one external address
Dynamic NAT (Many-to-many)
Many different internal addresses to many different external addresses
Port Address Translation
Many different internal addresses to one external address
What is PAT aka and is it commonly used?
Overloading NAT or PNAT, the most common to access the internet
