What is the difference between layer 2 and layer 3 in the OSI model?The layer2, Datalink layer is responsible for moving framesfrom one hop(node)to the next. And the layer3 which is networklayer is responsible for the delivery of individual packetsfrom source host to destination host.

What is the difference between a hub, switch, and router?A HUB is a common connection point fordevicesin anetwork. Hubs are commonly used to connectsegmentsof aLAN. Ahubcontains multipleports. When apacketarrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.A SWITCH innetworks, a device thatfiltersand forwardspacketsbetween LAN segments. Switches operate at the data link layer (layer 2) and sometimes thenetwork layer(layer 3)AROUTER is a devicethat forwardsdatapacketsalongnetworks. A router is connected to at least two networks, commonly twoLANsorWANsor a LAN and itsISP.snetwork. Routers are located atgateways, the places where two or more networks connect.

What is a VLAN?A virtual local area network (VLAN) is a logical group of workstations, servers and network devices that appear to be on the same LAN despite their geographical distribution.

What is the difference between TCP and UDP?

How do you distinguish a DNS problem from a network problem?What is a runt, Giant, and collision?A runt is a packet that fails to meet the minimum sizestandard. Ussually below 64 bytes. Occurs as a result ofa collision.

A giant is a packet that exceeds the size standard for themedium ussually grater then 1518 bytes . Caused bymalfunctioning equipment on your network.

Late collisions are packet collisions that occur after thewindow for a network collision closes.

What is a broadcast storm?A broadcast storm occurs when a network system is overwhelmed by continuous multicast or broadcast traffic. When different nodes are sending/broadcasting data over a network link, and the other network devices are rebroadcasting the data back to the network link in response, this will eventually cause the whole network to melt down and lead to the failure of network communication.

There are many reasons a broadcast storm occurs, including poor technology, low port rate switches and improper network configurations.

What is the purpose of VRRP?TheVirtual Router Redundancy Protocol(VRRP) is a computer networking protocol that provides for automatic assignment of availableInternet Protocol(IP) routers to participating hosts. This increases the availability and reliability of routing paths via automaticdefault gatewayselections on an IPsubnetwork.

What is a VPN?What information about a peer would I need to establish a VPN?peer IP addressencryption algorithm examples: DES, 3DES, AES256hash examples MD5, SHA1lifetime usually in kbits or secondsDiffe-Hellman exchangesecret key this is your pre-shared keyWhat is a full-class C in CIDR notation?Class C starts at 192.168.1.0 So the answer is 192.168.1.0/24

What is a default route?Adefault routeof a computer that is participating incomputer networkingis thepacketforwarding rule (route) taking effect when no other route can be determined for a givenInternet Protocol(IP) destination address.

What is a metric?Routermetricsaremetricsused by a router to make routing decisions

What is a MAC address?A media access controladdress(MAC address) is a unique identifier assigned to network interfaces for communications on the physical network segmentWhat is ARP/RARP?Describe a TCP connection sequenceWhat is MTU?1. In computer networking, themaximum transmission unit(MTU) of a communications protocol of a layer is the size (in bytes) of the largest protocol data unit that the layer can pass onwards.

What other TCP setting can you modify besides MTU to shorten packets?Shorten the byte using ping command -l option