Net Access India Network Security Engineer Interview Questions and Answers for Freshers

Packet flow in Palo Alto Firewall involves multiple stages including ingress, policy lookup, security policy enforcement, NAT, and egress.

• Packet enters the firewall through an ingress interface

• Firewall performs policy lookup to determine if the packet should be allowed or denied

• If allowed, the packet goes through security policy enforcement which includes threat prevention, URL filtering, etc.

• NAT (Network Address Trans...read more

OSPF (Open Shortest Path First) is a routing protocol used to determine the best path for data packets in a network.

• OSPF is a link-state routing protocol

• It uses Dijkstra's algorithm to calculate the shortest path

• OSPF routers exchange link-state advertisements (LSAs)

• It supports VLSM (Variable Length Subnet Masking)

• OSPF areas are used to divide large networks into smaller segments

DR and BDR in OSPF are elected based on priority values, with the highest priority becoming the DR and the second highest becoming the BDR.

• DR and BDR are elected within the OSPF network to ensure efficient communication and redundancy.

• The election process is based on priority values assigned to each router, with the highest priority becoming the DR and the second highest becoming the BDR.

• If two routers have the same pr...read more

VTP is a Cisco proprietary protocol used to manage VLAN configurations across a network.

• VTP allows for centralized management of VLANs by automatically propagating VLAN information to all switches in the network.

• It reduces the need to manually configure VLANs on each switch, making network administration more efficient.

• VTP operates in client, server, and transparent modes, with the server being the switch that can crea...read more

To troubleshoot a switch in ROMMON mode after a reboot, follow these steps.

• Check the configuration register value to ensure it is correct

• Verify the boot image and configuration file are present and accessible

• Attempt to boot the switch manually using the boot command

• If necessary, reload the switch with a valid IOS image from a TFTP server

The OS upgrade process for F5 devices involves careful planning, execution, and validation to ensure network reliability.

• Backup current configuration and data before starting the upgrade.

• Download the latest OS version from the F5 support site.

• Use the F5 Configuration Utility or CLI to upload the new OS image.

• Verify the integrity of the uploaded image using checksum.

• Schedule a maintenance window to minimize impact on us...read more

Troubleshooting APM sign-on issues involves checking configurations, logs, and network connectivity.

• Verify user credentials: Ensure the username and password are correct.

• Check APM configuration: Review the APM settings for any misconfigurations.

• Inspect logs: Look at the APM logs for error messages or warnings.

• Network connectivity: Ensure there are no network issues preventing access.

• Test with different browsers: Someti...read more