Security Intelligence Sources
...
Custom Block lists or feeds (or objects or groups)
Block specific IP addresses, URLs, or domain names using a manually-created list or feed (for IP addresses, you can also use network objects or groups.) For example, if you become aware of malicious sites or addresses that are not yet blocked by a feed, add these sites to a custom Security Intelligence list and add this custom list to the Block list in the Security Intelligence tab of your access control policy.
Security Intelligence Sources
...
Custom Block lists or feeds (or objects or groups)
Block specific IP addresses, URLs, or domain names using a manually-created list or feed (for IP addresses, you can also use network objects or groups.) For example, if you become aware of malicious sites or addresses that are not yet blocked by a feed, add these sites to a custom Security Intelligence list and add this custom list to the Block list in the Security Intelligence tab of your access control policy.
Security Intelligence Sources
...
Custom Block lists or feeds (or objects or groups)
Block specific IP addresses, URLs, or domain names using a manually-created list or feed (for IP addresses, you can also use network objects or groups.) For example, if you become aware of malicious sites or addresses that are not yet blocked by a feed, add these sites to a custom Security Intelligence list and add this custom list to the Block list in the Security Intelligence tab of your access control policy.

The traditional use of the pull model, where the client requests data from the network does not scale when what you want is near real-time data. Moreover, in some use cases, there is the need to be notified only when some data changes, like interfaces status, protocol neighbors change etc.
Model-Driven Telemetry is a new approach for network monitoring in which data is streamed from network devices continuously using a push model and provides near real-time access to operational statistics.
Applications can subscribe to specific data items they need, by using standard-based YANG data models over NETCONF-YANG. Cisco IOS XE streaming telemetry allows to push data off of the device to an external collector at a much higher frequency, more efficiently, as well as data on-change streaming.
The traditional use of the pull model, where the client requests data from the network does not scale when what you want is near real-time data. Moreover, in some use cases, there is the need to be notified only when some data changes, like interfaces status, protocol neighbors change etc.
Model-Driven Telemetry is a new approach for network monitoring in which data is streamed from network devices continuously using a push model and provides near real-time access to operational statistics.
Applications can subscribe to specific data items they need, by using standard-based YANG data models over NETCONF-YANG. Cisco IOS XE streaming telemetry allows to push data off of the device to an external collector at a much higher frequency, more efficiently, as well as data on-change streaming.
Reference:
The traditional use of the pull model, where the client requests data from the network does not scale when what you want is near real-time data. Moreover, in some use cases, there is the need to be notified only when some data changes, like interfaces status, protocol neighbors change etc.
Model-Driven Telemetry is a new approach for network monitoring in which data is streamed from network devices continuously using a push model and provides near real-time access to operational statistics.
Applications can subscribe to specific data items they need, by using standard-based YANG data models over NETCONF-YANG. Cisco IOS XE streaming telemetry allows to push data off of the device to an external collector at a much higher frequency, more efficiently, as well as data on-change streaming.

Explanation

Explanation
Explanation
To understand DHCP snooping we need to learn about DHCP spoofing attack first.
DHCP spoofing is a type of attack in that the attacker listens for DHCP Requests from clients and answers them with fake DHCP Response before the authorized DHCP Response comes to the clients. The fake DHCP Response often gives its IP address as the client default gateway -> all the traffic sent from the client will go through the attacker computer, the attacker becomes a "man-in-the-middle".
The attacker can have some ways to make sure its fake DHCP Response arrives first. In fact, if the attacker is "closer" than the DHCP Server then he doesn't need to do anything. Or he can DoS the DHCP Server so that it can't send the DHCP Response.
DHCP snooping can prevent DHCP spoofing attacks. DHCP snooping is a Cisco Catalyst feature that determines which switch ports can respond to DHCP requests. Ports are identified as trusted and untrusted.
Only ports that connect to an authorized DHCP server are trusted, and allowed to send all types of DHCP messages. All other ports on the switch are untrusted and can send only DHCP requests. If a DHCP response is seen on an untrusted port, the port is shut down.
The port connected to a DHCP server should be configured as trusted port with the "ip dhcp snooping trust" command. Other ports connecting to hosts are untrusted ports by default.
In this question, we need to configure the uplink to "trust" (under interface Gi1/0/1) as shown below.