VNX301 Versa Certified SD-WAN Specialist (VNX300) Questions and Answers

The correct answer is A . Versa CGNAT troubleshooting documentation provides a clear workflow for CGNAT issues. It first describes how to view CGNAT summary information using show orgs org-services < org > cgnat summary. It then shows how to view per-pool statistics using show orgs org-services < org > cgnat pools < pool-name > statistics. The sample output includes counters such as bindings-allocated , bindings-freed , alloc-failures , free-failures , out-of-address-errors , and out-of-ports-errors .

If these counters indicate failures, the next step is to inspect CGNAT state inside the vsmd daemon, including tenant state, ACL matching, pools, bindings, and source-port resources. This helps determine whether the issue is pool exhaustion, rule mismatch, resource allocation failure, or stale runtime state.

OSPF may affect routing but does not explain CGNAT allocation counters. Analytics may store logs but is not the dataplane authority for NAT allocation. Rebooting Analytics would not resolve CGNAT resource programming on the VOS device.

The correct answer is A . Versa’s handy troubleshooting CLI command reference lists show system package-info as the command used to view information about the VOS software image running on the CPE .

This command is useful before upgrade planning because it confirms the installed software package and helps validate whether the device is on the expected release. Administrators can compare the running version against the target upgrade image, verify upgrade prerequisites, and ensure that branch and Controller releases are compatible with required features such as internet speed testing, SD-WAN policy behavior, or security services.

show system uptime only tells how long the system has been running. show interfaces brief provides operational and administrative interface status, MAC address, tenant, VRF, and IP address information. show class-of-services interfaces brief helps troubleshoot QoS or shaping behavior. None of those commands directly identifies the VOS software package. Therefore, for checking the running image before an upgrade, the correct command is show system package-info.

The correct answer is A . Versa CGNAT troubleshooting documentation provides commands to inspect CGNAT state inside the vsmd daemon. To view summary information about configured tenants, the document instructs administrators to issue show cgnat tenants . The sample output shows each tenant ID and counters such as the number of configured rules, pools, DS-Lite service chains, 6RD service chains, static NAT entries, subscribers, endpoint-independent mapping entries, endpoint-independent filtering entries, and softwires.

This command is especially useful when CGNAT configuration appears correct in Director but translation is not happening, because it confirms whether the runtime dataplane process actually has the tenant CGNAT state.

show interfaces brief shows interface status and IP addressing. show alarms shows event notifications, and show system uptime shows how long the system has been running. These are useful operational commands but do not show CGNAT tenant programming inside vsmd.

The correct answer is B . The exhibit shows the OSPF neighbor in the exst state, which means Exchange Start . Versa documentation lists the OSPF neighbor state codes and identifies exst as “exchange start,” followed by exchange, loading, and full. In normal OSPF adjacency formation, neighbors progress through initialization and two-way communication before they negotiate database exchange. If the neighbor becomes stuck in ExStart or Exchange, a common and highly probable cause is an MTU mismatch between the two OSPF peers. During database description packet negotiation, the peers must agree on parameters that allow LSDB exchange; an MTU mismatch can prevent the adjacency from advancing to Full.

Option A is less likely because an area mismatch usually prevents the neighbor relationship from forming correctly rather than leaving it stuck in ExStart. Option C is also incorrect because the neighbor has already progressed beyond early states, which indicates that bidirectional communication has occurred. Option D is not the best answer because dropping OSPF multicast 224.0.0.5 would typically prevent discovery or keep the adjacency in an earlier state, not specifically in ExStart. Therefore, the probable cause is an interface MTU mismatch.

The correct answer is D . In the displayed post-staging template association order, the device template BMBF-TEMPLATE is applied before the QoS service template Ship-CoS-IT . Versa documentation explains that device templates, also called post-staging templates, provide the baseline configuration for devices, while service templates are service-specific configurations that can be applied to device configurations. It also states that service templates are associated with device groups and that, in a device group, the administrator can choose the order in which service templates are applied.

Because the QoS template is later in the shown association order, the final merged device configuration uses the Address object definition from the QoS template when the same object name exists in both templates. It does not automatically create two copies of the same Address object, because the object name is the key for the configuration element. It also should not fail merely because the same object name exists in a later template; the merge behavior resolves the effective configuration according to the template order. Therefore, the onboarded hub device receives the Server Address object version from Ship-CoS-IT, the QoS template.

The correct answer is B . The exhibit shows the branch interface summary in Versa Director with a Live Data column. To populate real-time bandwidth graphs for WAN circuits, the administrator must select Live Data for the WAN interfaces that need to be monitored. Versa monitoring documentation states that, from a Director node, you can monitor VOS devices and organizations, and that Director, together with Versa Analytics, can poll VOS devices in real time to understand what is happening on the devices. This real-time information can be displayed to assist with troubleshooting.

Because the question asks for the current bandwidth of each WAN circuit, historical analytics alone is not sufficient. The dashboard must poll live statistics from the selected WAN circuits. In the exhibit, not all WAN interfaces appear to have Live Data selected; therefore, the graph is not populated for all circuits. Refreshing the page does not enable polling and will not solve the missing data condition. Selecting only MPLS would populate only the MPLS circuit, not all WAN circuits. Unselecting and reselecting only the INET circuit would affect only that one interface. Therefore, Live Data must be selected for all WAN circuits whose current bandwidth should be displayed.

The correct answer is A . Versa link-bandwidth troubleshooting documentation explains that a VOS device can be configured as a Versa speed-test client, a Versa speed-test server, or both simultaneously. After the server is configured, the client starts the test by initiating a TCP-based connection toward the speed-test server. The server listens on port 5201 . The documentation includes an explicit note that if the VOS device is behind a firewall, port 5201 must be open .

This is different from the SD-WAN overlay data path, which commonly uses UDP-based transport encapsulation, and different from internet speed-test traffic, which uses other ports depending on the specific test type. In this scenario, the question states that a Versa speed-test server was configured, so the relevant requirement is TCP 5201 reachability from the client to the server.

TCP 443 may be used for management or web access, UDP 4790 is associated with SD-WAN transport encapsulation, and UDP 53 is DNS. None of those replace TCP 5201 for Versa speed-test server operation.

The correct answer is B . The requirement is to stop branch devices from sourcing traffic using IP addresses that do not belong to the branch. This is a source-address enforcement problem, so the correct control is a stateful firewall policy that permits only traffic whose source IP address matches the valid branch LAN prefix or branch-assigned address range. Versa’s stateful firewall configuration documentation explains that firewall policy rules include source matching, where the administrator selects the source zone and one or more source addresses to which the rule applies.

By creating an allow rule for the legitimate branch source prefixes and placing a deny rule for all other sources from the branch LAN zone, the VOS device prevents spoofed or unauthorized source addresses from leaving the branch. This is consistent with Versa security policy behavior, where firewall rules evaluate traffic based on zones, addresses, services, applications, and other match criteria. Captive portal verifies user identity but does not directly prevent IP spoofing. An IP filter profile based on applications does not ensure the source address belongs to the branch. Option D is incorrect because allowing traffic to the assigned LAN range controls destination traffic, while this requirement is about validating the source IP address of outbound branch traffic.

The correct answer is A . Versa throughput troubleshooting documentation includes a specific section titled Check that Packets Are not Dropped by CoS . It states that if a CoS shaper or rate limiter is configured on the VOS device, it may drop packets when traffic exceeds the configured shaping rate. To check whether CoS is dropping packets, Versa recommends commands including show class-of-services interfaces brief and show class-of-services interfaces detail interface-name.

The detailed interface output displays traffic statistics such as TX packets, TX packets dropped, TX bytes, TX bytes dropped, and per-traffic-class drops. This is exactly the evidence needed to confirm whether shaping or QoS enforcement is causing the observed loss.

show alarms last-n 10 may reveal major events but will not provide per-interface CoS drop counters. show system uptime only indicates how long the system has been running. show cgnat tenants is relevant for NAT state and tenant CGNAT resources, not QoS drops.

In the exhibit, the Add Associate Interface/Network window has Interface selected, and the interface name is set to vni-0/0 . The DSCP rewrite option is not available because rewrite behavior is intended to be applied at the network association level for the WAN network, not directly while associating only the physical/logical interface. For WAN-facing CoS, the scheduler and shaping parameters can be attached to an interface, but DSCP rewrite policies are applied to remark traffic as it exits through a network context.

Versa SD-WAN design documentation explains that QoS rewrite rules rewrite packet QoS attributes as packets leave the VOS device, and that rewrite rules can modify IEEE 802.1p bits, IPv4 TOS/DSCP bits, and IPv6 traffic class bits. It also explains that a rewrite policy is commonly applied on a WAN network to remark traffic based on the forwarding class and loss priority assigned by QoS or App QoS policies. In the design example, Versa explicitly describes applying a QoS propagation or rewrite policy on the MPLS WAN network to remark traffic to a DSCP value. Therefore, the issue is the association type: it is set to Interface, not Network.

The correct action is to update the WAN gateway IP address in Device Bind Data and onboard the branch appliance again. Device Bind Data supplies site-specific values, such as WAN interface addressing and gateway information, that are merged with the workflow and template configuration during onboarding. If the wrong WAN gateway is entered, the branch may activate successfully from a workflow perspective, but the resulting WAN routing configuration is incorrect. As a result, the branch cannot establish proper transport reachability to the Controller. Versa troubleshooting documentation explains that, after establishing transport connectivity from a branch to a Controller, at least one WAN interface must be available, and the branch then establishes IKE-based IPsec connectivity to the Controller. If that IKE/IPsec connectivity fails, the Controller-facing ptvi interface remains down.

Changing the configuration only from the Appliance context is not the best answer because the incorrect value originated in the bind-data source used for provisioning. Modifying it manually from the branch CLI is also not recommended because the device is managed by Versa Director and template-driven configuration. Resetting the device does not automatically discover or “ping” the correct gateway. The correct remediation is to fix the bind data and repeat onboarding so the branch receives the correct generated configuration.

The exhibit shows the Add CGNAT Pool configuration with the IP Address/Range option selected. The configured address range is named Visitors , with a low address of 192.168.10.100 and a high address of 192.168.10.150 . In CGNAT, this pool defines the translated source address resource used by matching NAT rules; it does not define the original inside source hosts. Therefore, matching sessions will have their source address translated to an address from this configured pool range, which makes option C correct. Versa’s CGNAT configuration examples show that a rule matches original source and destination prefixes, and then attaches a translated source pool to perform NAT.

The correct answer is A . In Versa SD-WAN forwarding profiles, next-hop priorities define which circuits are preferred. When the Load Balance next-hop selection method is used and two circuits share the same priority, sessions can be distributed across those equal-priority paths as long as they are usable and SLA-compliant. A lower priority number represents a more preferred group than a higher priority number. Therefore, two circuits with priority 1 are preferred over LTE with priority 2 .

In this scenario, both internet circuits are healthy and both have priority 1. The VOS device should load-balance sessions across those two circuits. LTE remains available as a lower-priority backup path and would normally be considered only when the preferred internet circuits are unavailable, fail path checks, or no longer meet the applicable policy conditions.

Traffic is not replicated because replication is a separate feature and not implied by Load Balance. The branch does not drop traffic while valid paths exist. LTE is not preferred merely because its priority number is higher; in path selection, priority 1 is preferred over priority 2.

The correct answer is A . Versa CGNAT troubleshooting documentation states that, after connecting to the vsmd daemon, administrators can view CGNAT access lists used for traffic matching with the command show cgnat acl info < tenant-id > . The sample output shows ACL handle, rule ID, category, precedence, VRF, source IP, destination IP, tenant ID, and total filters.

This is the correct command when NAT configuration appears present but translations do not occur, because it verifies whether the runtime dataplane has the correct traffic-match rules. If the source prefix, destination prefix, VRF, or precedence is wrong, the session may never match the NAT rule, and no translation will be applied.

show system status checks system services. show device clients shows active and failed sessions, CPU usage per session, and memory load for processes. show system storage shows disk usage. These commands are useful in other troubleshooting workflows, but they do not validate CGNAT ACL matching criteria for tenant traffic.

The correct answers are A and C . If the onboarding VPN tunnel from the branch device to the Controller is up, the branch has reached at least the initial staging/control connectivity stage. Versa troubleshooting documentation explains that after a branch establishes IPsec connectivity to the Controller, the Controller sends a branch-connect notification to Versa Director. In response, Director pushes staging configuration and continues the onboarding lifecycle. If the expected later notification is not seen, the branch has not completed staging and further onboarding/debug steps are required.

The Tasks list in Versa Director is useful because device deployment and onboarding actions are executed as Director tasks. If template commit, workflow deployment, device claiming, or configuration push fails, the task output can show the error. The Unknown Devices dashboard is also relevant because a device that reaches the Controller but cannot be matched or fully associated with an expected workflow/appliance record may appear as an unknown device awaiting administrative review. The Monitor dashboard is not the best choice because the device is missing from the Appliances list and has not completed onboarding. Resource Pool is related to connector resources, not branch onboarding completion.