Prelim - Data Com 2

Web Management (In-band GUI)

A management access method that provides a graphical user interface using a web browser with HTTPS or HTTP.

hostname

A command used in global configuration mode to name a device and distinguish it from others in the network.

banner motd

A command used in global configuration mode to provide legal notification of unauthorized access.

no shutdown

A command used to activate an interface.

clock rate

A command required on a serial interface with the DCE cable end when configuring in a lab environment.

show running-config interface

A command that displays the specific commands configured on a specified interface.

show interfaces

A verification command that displays detailed interface information and packet flow counts.

show ip interface

A command that displays the IPv4 related information for all interfaces on a router.

show ipv6 interface brief

A command used to verify that IPv6 Layers 1 and 2 are operational by checking for an up/up status.

show ipv6 interface

A command that shows the interface status and all IPv6 addresses belonging to that interface.

Pipe character (|)

A character used to filter the output of show commands.

Command History

A feature that stores previously executed commands, which can be recalled using the Up Arrow key or Ctrl+P.

terminal history size

A user EXEC command used to change the default number of lines stored in the command history buffer.

show history

A privileged EXEC command used to display the contents of the command history buffer.

flash:

The Cisco IOS file system used to store the Cisco IOS software image.

usbflash:

The Cisco IOS file system used for external storage.

Tab key

A CLI shortcut that automatically completes partial commands to increase productivity and reduce typing errors.

Ctrl+A

A keyboard shortcut that moves the cursor to the beginning of the command line.

Ctrl+E

A keyboard shortcut that moves the cursor to the end of the command line.

Ctrl+U

A keyboard shortcut used to clear the command line.

Ctrl+Z

A keyboard shortcut that exits the current configuration mode and returns to Privileged EXEC mode.

show version

A verification command used to display device information and verify the Cisco IOS software image.

show inventory

A verification command used to display hardware information for the device.

Network Documentation

Records of important information about the network infrastructure, including topology, IP addressing, and policies.

Interface Documentation

Records that identify how devices are connected, including interface IDs, VLAN assignments, and operational status.

Configuration Documentation

Records maintained for every configuration change, documenting the date, administrator, and purpose of the change.

Network Inventory

Documentation of all network equipment, recording details such as device model, serial number, and physical location.

Static Routing

Manually entering routes into a router's table rather than relying on dynamic routing protocols to automatically update them.

Dynamic Routing

Automatically adapts to topology changes but requires extra CPU, memory, and link bandwidth resources.

Standard Static Route

Manually configured route to connect to a specific remote network or a stub network.

Default Static Route

Matches all packets that do not have a specific entry in the routing table, creating a Gateway of Last Resort (0.0.0.0/0 or ::/0).

Floating Static Route

A backup path intentionally configured with a higher administrative distance than the primary routing protocol so it remains hidden until the primary route fails.

Host Route

A route to a single specific device, using a 32-bit mask for IPv4 or a 128-bit mask for IPv6.

Next-Hop IP Configuration

Identifies the next router's address but requires a recursive lookup to find the correct exit interface.

Directly Connected Configuration

Specifies only the outgoing interface, directly attaching the route without a recursive lookup.

Fully Specified Configuration

Dictates both the next-hop IP and the exit interface; mandatory when using IPv6 link-local addresses as the next hop.

show ip route / show ipv6 route

Commands used to verify routing tables and specific routing entries.

ping / traceroute

Commands used to test end-to-end connectivity and pinpoint exactly where a network path breaks.

show ip interface brief

Command used to investigate current interface status.

show cdp neighbors

Command used to identify and investigate directly connected devices.

Administrative Distance (AD)

A value representing the trustworthiness of a route source; standard static routes have an AD of 1.

Stub Network

A network accessed by a single route and with only one exit point, making it an ideal use case for static routing.

Gateway of Last Resort

The router to which all unroutable packets are sent, usually established by configuring a default static route.

Recursive Route Lookup

The process where a router must perform multiple routing table lookups to resolve a next-hop IP address to a specific exit interface.

Null0 Interface

A logical interface that acts as a discard point; traffic routed to Null0 is dropped, often used to prevent routing loops.

Summary Static Route

A single static route configured to encompass multiple specific network routes, reducing the overall size of the routing table.

Equal-Cost Load Balancing

The practice of configuring multiple static routes to the same destination with the same metrics to distribute traffic across multiple paths.

ip route

The Cisco IOS command used in global configuration mode to create an IPv4 static route.

ipv6 route

The Cisco IOS command used in global configuration mode to create an IPv6 static route.

Dynamic Routing

Routing that automatically learns and maintains routes to remote networks and adapts to topology changes.

Static Routing

Routing that is manually configured, does not adapt automatically, and is suitable for small or predictable networks.

Data structures

Tables or databases kept in RAM that serve as a main component of dynamic routing protocols.

Routing protocol messages

Messages used to discover neighboring routers, exchange routing information, and maintain accurate network information.

Algorithms

Components used in dynamic routing protocols to facilitate learning routing information and for best path determination.

RIPv2

A classless, distance-vector routing protocol that uses hop count as its metric and includes the subnet mask with network addresses in routing updates.

OSPF

A link-state dynamic routing protocol commonly used in enterprise networks that uses cost as its metric.

EIGRP

An advanced distance-vector routing protocol that uses bandwidth and delay as metrics.

BGP

A path-vector dynamic routing protocol.

Directly Connected Networks

Networks that are automatically added to the routing table when the interface is configured and activated.

Route source

A routing table entry that identifies how the network was learned by the router.

Destination network

A routing table entry that identifies the remote network.

Administrative distance (AD)

A value indicating how trustworthy a route source is; a lower AD is more preferred when a router learns the same destination from different sources.

Metric

A value assigned to reach a remote network that determines which path is preferred within a routing protocol; a lower value is better.

Next-hop

The IPv4 address of the next router that a packet should be forwarded to.

Route timestamp

The time since the route was updated.

Outgoing interface

The exit interface on a router used to forward a packet to its destination.

Longest match

The route in the routing table that has the greatest number of far left matching bits with the destination IPv4 address of the packet; it is always the preferred route.

Hop count

The metric used by the RIPv2 routing protocol, which has a maximum usable distance of 15 hops.

Distance-vector

A classification of dynamic routing protocols, such as RIPv2, that use metrics like hop count to select paths.

Link-state

A classification of dynamic routing protocols, such as OSPF, that use link-state information and cost to calculate routes.

Advanced distance-vector

A classification of dynamic routing protocols, such as EIGRP, that use bandwidth and delay to select paths.

Path-vector

A classification of dynamic routing protocols, such as BGP.

Cost

The metric used by the OSPF routing protocol to select routes.

Bandwidth and delay

The metrics used by the EIGRP routing protocol to select routes.

CIDR (Classless Inter-Domain Routing)

A routing method supported by RIPv2.

VLSM (Variable Length Subnet Mask)

A subnetting feature supported by RIPv2.

224.0.0.9

The multicast IP address used by RIPv2 to send routing updates.

no auto-summary

The command used to disable the automatic summarization of routing updates in RIP.

16 hops

The distance at which a network is considered unreachable in the RIPv2 protocol.

S

The routing table source code that identifies a Static Route.

D

The routing table source code that identifies a route learned via the EIGRP routing protocol.

O

The routing table source code that identifies a route learned via the OSPF routing protocol.

R

The routing table source code that identifies a route learned via the RIP routing protocol.

C

The routing table source code that identifies a directly connected network.

OSPF

A link-state IGP that uses the SPF (Dijkstra) algorithm to calculate shortest paths based on cost, with a default administrative distance of 110.

EIGRP

An advanced distance-vector routing protocol that uses the DUAL algorithm and a composite metric to select efficient, loop-free paths.

Cost

The metric used by the OSPF routing protocol, where a lower total value is preferred.

Composite metric

The primary metric used by EIGRP, determined by bandwidth and delay by default.

Area 0

The backbone area that is central to multi-area OSPF configurations.

LSAs (Link-State Advertisements)

Information packets that describe topology information and are stored in the link-state database in OSPF.

SPF (Shortest Path First)

An algorithm used by OSPF to calculate the shortest-path tree from the router's perspective.

DUAL

The core algorithm used by EIGRP that maintains loop-free, fast convergence.

Router ID

A value that uniquely identifies an OSPF router.