Download Cisco Certified Network Associate (200-301 CCNA).ITExamAnswers.200-301.2022-08-12.1e.669q.vcex

If we want to get an IP address from the DHCP server on a Cisco device, we can use the command "ip address dhcp".
Note: The command "ip helper-address" enables a router to become a DHCP Relay Agent.
Reference:  
https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipaddr_dhcp/configuration/12-4/dhcp-12-4-book/config-dhcp-client.html

When an interface is configured with IPv6 address, it automatically joins the all nodes (FF02::1) and solicited-node (FF02::1:FFxx:xxxx) multicast groups. The all-node group is used to communicate with all interfaces on the local link, and the solicited-nodes multicast group is required for link-layer address resolution. Routers also join a third multicast group, the all-routers group (FF02::2).
Reference:
https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipv6/configuration/xe-3s/ipv6-xe-36s-book/ip6-multicast.html

JSON data is written as name/value pairs.
A name/value pair consists of a field name (in double quotes), followed by a colon, followed by a value:
"name":"Mark"
JSON can use arrays. Array values must be of type string, number, object, array, boolean or null..
For example:
{
"name":"John",
"age":30,
"cars":[ "Ford", "BMW", "Fiat" ]
}

A IPv6 Unique Local Address is an IPv6 address in the block FC00::/7. It is the approximate IPv6 counterpart of the IPv4 private address. It is not routable on the global Internet.
Note: In the past, Site-local addresses (FEC0::/10) are equivalent to private IP addresses in IPv4 but now they are deprecated.
Link-local addresses only used for communications within the local subnet. It is usually created dynamically using a link-local prefix of FE80::/10 and a 64-bit interface identifier (based on 48-bit MAC address).

OpenFlow is a well-known southbound API. OpenFlow defines the way the SDN Controller should interact with the forwarding plane to make adjustments to the network, so it can better adapt to changing business requirements.
The Network Configuration Protocol (NetConf) uses Extensible Markup Language (XML) to install, manipulate and delete configuration to network devices.
Other southbound APIs are:
onePK: a Cisco proprietary SBI to inspect or modify the network element configuration without hardware upgrades.
OpFlex: an open-standard, distributed control system. It send "summary policy" to network elements.

This is an example of how two-factor authentication (2FA) works:
The user logs in to the website or service with their username and password.
The password is validated by an authentication server and, if correct, the user becomes eligible for the second factor.
The authentication server sends a unique code to the user's second-factor method (such as a smartphone app).
The user confirms their identity by providing the additional authentication for their second-factor method.

Cisco DNA Center offers 360-degree extensibility through four distinct types of platform capabilities:
Intent-based APIs leverage the controller and enable business and IT applications to deliver intent to the network and to reap network analytics and insights for IT and business innovation.
Process adapters, built on integration APIs, allow integration with other IT and network systems to streamline IT operations and processes.
Domain adapters, built on integration APIs, allow integration with other infrastructure domains such as data center, WAN, and security to deliver a consistent intent-based infrastructure across the entire IT environment.
SDKs allow management to be extended to third-party vendor's network devices to offer support for diverse environments.