350-701 Leak Questions

To create an access control list (ACL) on a Cisco Adaptive Security Appliance (ASA) firewall, you need to use the access-list command followed by the name of the ACL, the action (permit or deny), the protocol, the source address and mask, and the destination address and mask. For example, to permit HTTP traffic from the inside network 192.168.1.0/24 to any destination on the internet, you can use this command:

access-list inside_access_in permit tcp 192.168.1.0 255.255.255.0 any eq www

This command creates an ACL named inside_access_in that permits TCP traffic from the source network 192.168.1.0/24 to any destination with the destination port equal to 80 (www). The eq keyword is used to specify the port number or name. You can also use the range keyword to specify a range of ports.

To apply the ACL to an interface, you need to use the access-group command followed by the name of the ACL and the direction (in or out). For example, to apply the ACL to the inside interface in the inbound direction, you can use this command:

access-group inside_access_in in interface inside

This command applies the ACL inside_access_in to the interface named inside in the inbound direction. This means that the ACL will filter the traffic that enters the firewall through the inside interface.

Option D is the only option that matches the syntax of the access-list command for the ASA firewall. Option A is incorrect because it uses the ip keyword instead of the tcp keyword. Option B is incorrect because it uses the any keyword for both the source and destination addresses. Option C is incorrect because it uses the host keyword for the source address, which is not valid for a network address.

References:

• Configure ASA Access Control List for Various Scenarios
• Cisco ASA Access Lists Concepts and Configuration
• How to Configure Access Control Lists (ACL) on Cisco ASA 5500 Firewalls

Southbound APIs are used to communicate between the SDN Controller and the switches and routers of the network. They can be open-source or proprietary. They facilitate control over the network and enable the SDN Controller to dynamically make changes according to real-time demands and needs. OpenFlow and OpFlex are two examples of southbound APIs. OpenFlow, which was developed by the Open Networking Foundation (ONF), is the first and probably most well-known southbound interface. 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. With OpenFlow, entries can be added and removed to the internal flow-table of switches and routers to make the network more responsive to real-time traffic demands. OpFlex, which was proposed by Cisco, is another southbound interface that uses a declarative model to communicate policies and state between the controller and the network devices. OpFlex allows the network devices to retain some intelligence and autonomy, while still being managed by the controller. OpFlex is designed to be flexible and extensible, and can support different types of network devices and services. Services running over the network, external application APIs, and applications running over the network are not southbound APIs, as they do not directly communicate between the controller and the network devices. Therefore, the correct answer is B and E. References :=

Some possible references are:

• What are SDN Southbound APIs? - Where they are used. - SDxCentral
• SDN North-bound and South-bound APIs and Interfaces
• Cisco Application Centric Infrastructure Fundamentals

DHCP option 82 is a feature that allows the network access device (NAD) to insert additional information into the DHCP request packet from the endpoint. This information can include the switch ID, port number, VLAN ID, and other attributes that can help Cisco ISE to identify and profile the endpoint. Cisco ISE can use DHCP option 82 to assign the endpoint to the appropriate identity group, policy, and authorization profile. DHCP option 82 is also useful to prevent rogue DHCP servers from assigning IP addresses to endpoints, as Cisco ISE can verify the legitimacy of the DHCP request based on the option 82 data. To use DHCP option 82, the NAD must be configured to enable this feature and send the option 82 data to Cisco ISE. Cisco ISE must also be configured to accept and parse the option 82 data from the NAD. For more details on how to configure DHCP option 82 on Cisco ISE and NAD, see the references below. References:

• Configuring the DHCP Probe
• Securing Your Network From DHCP Risks
• Can we use ISE as DHCP/DNS server to prevent guest traffic using …

Northbound and southbound APIs are two types of interfaces that enable communication between different layers of the SDN architecture. Northbound APIs relay information between the controller and the applications or policy engines, while southbound APIs relay information between the controller and the network devices.

Northbound APIs allow applications to request network services or resources from the controller, such as bandwidth, latency, security, or routing. The controller then translates these requests into network configurations and applies them to the network devices via the southbound APIs. Northbound APIs typically use RESTful API methods such as GET, POST, and DELETE to communicate with the controller.

Southbound APIs allow the controller to program the network devices to perform forwarding and other functions. The controller can use different protocols or standards to communicate with the network devices, depending on their capabilities and vendor-specific features. Some common examples of southbound APIs are CLI, SNMP, RESTCONF, NETCONF, OpenFlow, and OpFlex.

References:

• Software-Defined Networking (SDN) Definition - Cisco
• Software-Defined Networking Security and Network … - Cisco Press
• Cisco SDN – Software Defined Networking Explained - Study-CCNA
• SDN Network - Cisco Community