
When you configure a network device, say Router A with an IP address of 10.10.10.1, to operate as an [Network Time Protocol (NTP)](/network-time-protocol-ntp) server, you don’t actually have to explicitly configure it as a server. When an NTP client such as Router B is configured with the command `ntp server 10.10.10.1` this makes Router A the NTP server, and Router B the NTP client.

Router A in turn can also be an NTP client.  For example, the `ntp server pool.ntp.org` command actually makes Router A an NTP client to the pool.ntp.org server, but at the same time it retains the role of NTP server for Router B.

Now the `master` command is simply used to let a device know to consider its own clock as the NTP source, and it is also used to manually set a stratum number for this NTP source. This way, clients of this device will adopt their stratum number based on the locally configured one. This type of configuration means that no external NTP sources are used for synchronization.

## Links

https://networklessons.com/cisco/ccie-enterprise-infrastructure/cisco-network-time-protocol-ntp

NTP server and client and the master command

Multicast PIM sparse mode

Multicast PIM sparse-dense mode

Multicast PIM what triggers an assert forwarder election

Multicast PIM with multiple RPs

Multicast PIM with multiple mapping-agents

Multicast PIM-assert forwarder election

Multicast SPT and RPT

Multicast bidirectional PIM advantages

Multicast boundary filtering - filter auto RP

Multicast enabling Bidir in BSR mode

Multicast ip pim autorp listener

Multicast ip pim rp-address override

Multicast load splitting across equal-cost paths

Multicast local subnetwork address range

Multicast mapping IP to MAC addresses

Multicast mapping agent IGMP membership report

Multicast ping on a Nexus device

Multicast using Anycast RP with Auto-RP and BSR

Multicast

NAT - Translation Table

NAT - Twice NAT

NAT - Understanding debug nat detailed output

NAT - Virtual Interface (NVI)

NAT - What is Policy NAT

NAT - add-route keyword

NAT - ip nat inside destination

NAT - ports used for translation

NAT - show NAT translations

NAT - translate address not directly connected to edge device

NAT Extendable on Cisco IOS

NAT Order of Operation

NAT address naming conventions

NAT and IPv6

NAT how port numbers are chosen when using PAT

NAT intra-VRF NAT

NAT port forwarding - specifying outside IP address

NAT prefix-length keyword on nat pool command

NAT vrf-aware

NBAR classifies only established sessions

NETCONF

NHRP - Authentication

NHRP - Destination Protocol Address

NHRP - Holding Time

NHRP - resolution redirect from hub

NHRP show ip nhrp flags

NHRP

NIC Promiscuous Mode

NTP - securing with MD5 authentication and a Windows NTP server

NTP poll interval

NTP troubleshooting and debugging tools

NTP versions 3 and 4

Native VLAN Traffic Flow on Trunk Ports

Native VLAN

Native VLANs and untagged frames

NetFlow - Flexible NetFlow

NetFlow - Flow Samplers

NetFlow - applying to an SVI

NetFlow - what is a flow

NetFlow local cache size

NetFlow

Network - BUM Traffic

Network - Discontiguous or Discontinuous

Network - Discontiguous

Network - Example of communication, encapsulation, and decapsulation, between hosts

Network - Layer 3 network

Network - Monitoring multiple IPs of a single device with Observium

Network - Observium vs LibreNMS

Network - Simultaneous network traffic handling

Network - Transient traffic

Network - Two Way Active Measurement Protocol (TWAMP)

Network - control plane

Network - data plane

Network Address Translation (NAT)

Network Collisions

Network Design - Choosing a technology for multiple datacenter topology

Network Design - Load Balancing vs Load Sharing

Network Design - Spine and leaf architecture

Network Design - Switch oversubscription ratios

Network Design - Traffic Engineering

Network Design - on-premises and off-premises

Network Design Achieving Redundancy with PE Devices

Network Design Considerations Involving PE and P Routers

Network Flapping

Network Management Areas

Network Speed, Bandwidth, and Throughput

Network Time Protocol (NTP)

Network design - confine VLANs to as few access switches as possible

Network planes

Networking - Understanding Chassis devices

Networking - what is a socket

Networks - Overlay Network

Networks - Overlay Transport Virtualization (OTV)

Networks - Spanning Layer 2 networks across remote sites

Networks - Underlay Network

Next Generation Multicast Virtual Private Network (NG-MVPN)

Next Hop

Nexus - using vPC with HSRP

Nexus - what is vPC

Nexus lacp rate fast