Top 12 Network Operations Center (NOC) Interview Questions You Must Prepare 19.May.2024

This symptom is the sign of abnormal functionality in a router. First we should know the exact reason for increased CPU utilization, and we can use “show processes cpu ,” “show interface stat” commands to check the process utilizations. It could be due to high traffic flow (congestion), complex ACL or VPN deployments, ARP/TCP issues etc.

Every switch series has its own set of recovery methods. Here you can describe the procedure of password recovery for the switches on which you have shown your work experience. You can also refer following links to get an idea of password recovery on well-known Cisco switches.

If BGP peer is in idle state then it could be due to physical connectivity failure or neighbor is not defined with properly with respective AS. In connect state, BGP tries to establish TCP session over port number 179 if it fails to establish TCP connection then it goes to Active state where it retries to establish TCP connection. By using debug ip bgp and debug ip tcp tractions commands, we can find out the exact cause of TCP connection failure. Lack of “update-source” or “ebgp-multihop” command can also be a reason for neighbor active state;

IP and trport layer headers for information related to source and destination IP addresses, port numbers etc.

The overall bandwidth of an EtherChannel interface depends on its active member links. An EtherChannel with 8 active 100 Mbps links should indicate a bandwidth of 800 Mbps and, if one of its physical ports fails, the available bandwidth of port-channel interface will be evaluated as 700Mbps without flapping the port-channel.

A web application firewall or a layer 7 firewall can be used for the purpose.

If OSPF is configured on low bandwidth links, IP-OSPF-Trmit-Delay is used to increase the time of the age field of a LSA update. By default it is set to 1 second and, to make it effective, it must be added before trmission over a link.

It could be normal if it is less than 1% of total traffic on that interface with no packet drop

And it is recommended to resolve link issues in case cyclic redundancy check (CRC) errors are more than 1% of the total interface traffic. The most common reason for receiving CRC errors is the duplex setting, as most of providers set their interface to “auto” mode.