300-635 Automating Cisco Data Center Networking Solutions (DCNAUTO) Practice Questions
Prepare for 300-635 with more than an answer.
- Exam fee
- $300 USD
- Level
- Professional
- Valid for
- 3 years
Domains covered on the exam 4
- Network Programmability Foundation10%
- Controller Based Data Center Networking30%
- Data Center Device-centric Networking30%
- Data Center Compute30%
- 1
An engineer has written an Ansible playbook to configure a new VLAN on a Nexus switch. The playbook fails with an authentication error. The playbook uses
ansible_userandansible_passwordfor credentials. The engineer has confirmed the credentials are correct and work via SSH. The switch is configured for RADIUS authentication. What is the most likely reason for the playbook's failure?Show answer details
Correct answer: D
When using external AAA servers like RADIUS with NX-OS, programmatic access (like that used by Ansible) often requires the user to be assigned a specific role with sufficient privileges (e.g.,
network-admin). Even if the credentials are correct for interactive SSH login, if the RADIUS server does not return the correct role authorization attributes for a non-interactive session, the login will be rejected, resulting in an authentication failure from Ansible's perspective. - 2
The signature for a Cisco Intersight API request is generated by creating a string that includes the HTTP method, host, date, request target, and a digest of the request body. This entire string is then signed using a private key. What hashing algorithm is used to create the digest and the final signature?
sequenceDiagram participant Client participant Intersight API Client->>Client: Create Digest from request body (SHA-256) Client->>Client: Construct Signature String Client->>Client: Sign the string with Private Key (RSA-SHA256) Client->>Intersight API: Send Request with Signature Header Intersight API->>Intersight API: Re-create signature string Intersight API->>Intersight API: Verify signature with Public Key alt Signature Valid Intersight API-->>Client: 200 OK else Signature Invalid Intersight API-->>Client: 401 Unauthorized endShow answer details
Correct answer: B
The Cisco Intersight API authentication method uses the HTTP Signature scheme. It requires creating a SHA-256 hash of the request body to generate a digest. The final signature string is then signed using the RSA-SHA256 algorithm with the user's private key. This ensures both the integrity of the request body and the authenticity of the caller.
- 3
A developer working in a Git repository has made several changes to a tracked file. They want to see the specific line-by-line differences between their current working directory version and the last committed version. Which Git command should they use?
Show answer details
Correct answer: C
The
git diffcommand is used to show changes between commits, commit and working tree, etc. When run without arguments, it specifically shows the differences between the files in the working directory and the index (the last committed version, for tracked files that have not been staged). - 4
True or False: The
cisco.aci.aci_tenantAnsible module is idempotent, meaning if you run a playbook to create a tenant that already exists with the same configuration, the module will make no changes and report a status of 'ok'.Show answer details
Correct answer: A
The statement is true. A core principle of Ansible is idempotency. Well-written modules, like those in the
cisco.acicollection, check the current state of the target system. If the desired state (e.g., a tenant named 'Prod' exists) already matches the current state, the module will not perform any actions and will report a green 'ok' status, indicating no changes were necessary. - 5
A network engineer is using the Nexus NX-API REST interface to retrieve the output of the
show versioncommand. Which of the following represents the correctly formatted JSON-RPC payload to send in the body of the POST request?Show answer details
Correct answer: B
This is the correct JSON-RPC 2.0 format for the NX-API REST interface. It specifies the version (
jsonrpc), the method to execute (cli), the parameters for that method (the command itself in thecmdkey), and a unique request identifier (id). - 6
A consultant is using UCS PowerTool to create a new Service Profile on a Cisco UCS Manager. Which PowerShell cmdlet is used to create the new Service Profile object?
Show answer details
Correct answer: C
UCS PowerTool follows the standard PowerShell
Verb-Nounnaming convention. TheAdd-verb is used for creating new objects. Therefore,Add-UcsServiceProfileis the correct cmdlet to create a new Service Profile in UCS Manager. - 7
What is a primary benefit of integrating Kubernetes with the Cisco ACI CNI plugin compared to using a standard overlay network like Flannel or Calico?
Show answer details
Correct answer: B
The key benefit of the ACI CNI plugin is the deep integration it provides. Kubernetes objects like namespaces and pods can be mapped directly to ACI objects like EPGs. This allows network policies (Contracts) to be applied between pods, and between pods and external resources (bare-metal servers, VMs, mainframes) using the same ACI policy model, providing unified security and visibility.
- 8
A DevOps engineer is tasked with automating the deployment of service profiles in a Cisco UCS environment managed by UCS Manager. The primary requirements are that the automation solution must be declarative, idempotent, and easily integrated into an existing CI/CD pipeline that uses YAML for definitions. Which tool best satisfies all these requirements?
Show answer details
Correct answer: C
Ansible is a declarative automation tool that uses YAML-based playbooks, fitting perfectly into the CI/CD pipeline requirements. The modules in the cisco.ucs collection are designed to be idempotent, meaning they will only make changes if the current state does not match the desired state defined in the playbook. This makes it the optimal choice for meeting all the stated requirements.
- 9
A network administrator is troubleshooting a PowerOn Auto Provisioning (POAP) failure on a new Nexus 9300 switch. The switch successfully obtains an IP address from DHCP but fails to download the Python configuration script from the TFTP server. The DHCP server is confirmed to be providing the correct script name and TFTP server IP. Which two potential issues are the most likely cause of this failure? (Choose two.)
Show answer details
Correct answer: B, D
POAP operates within the management VRF by default. If the TFTP server is in a different subnet, the switch must have a default gateway (provided by DHCP) and proper routing to reach it. Lack of IP reachability is a common cause of POAP script download failures.
Even with full IP reachability (e.g., ICMP pings work), network security policies can block specific protocols. TFTP uses UDP port 69, which might be blocked by an intermediate firewall or an ACL, preventing the file transfer from succeeding.
- 10
An automation engineer needs to construct a REST API call to Cisco Intersight to retrieve all server profiles that are in an 'Unassigned' state. Based on the Intersight API documentation, the endpoint for server profiles is
/api/v1/server/Profilesand it supports OData query options. Which API call correctly filters the results?Show answer details
Correct answer: B
This is the correct syntax for an OData query. The '$filter' parameter is used to specify the filtering condition, where the 'Status' property must be equal ('eq') to the string 'Unassigned'.
