Cisco advanced Routing and switching for Linux systems

Day

1. What is a Vlan? The role of VLANs?

Vlan: Virtual local Area Network

Role: Broadcast control, increased security, bandwidth utilization, reduced latency

2. What is Trunk? What are the Trunk patterns?

Trunk: Trunk link that can host multiple VLANs

Trunk mode:

Access (Access)

Main road (Trunk)

Dynamic Desire (desirable) active

Dynamic Automatic (Auto) passive

3. What is the role of EtherChannel?

Eternetchannel (Ethernet channel)

Role:

1) Multi-line load balancing, increased bandwidth

2) Line Backup (when one line fails, other lines communicate, no packet loss)

4. What is DHCP? What is the role of DHCP?

DHCP: Dynamic Host Configuration Protocol

Role: Automatically assign IP addresses to clients

Day 02

1. What is a three layer switch? What is the difference between a two-layer interchange and a three-tier interchange and route?

Layer three switches: switches with network layer routing capabilities called layer three switches

Difference:

The second layer switch: belongs to the data Link layer device, which realizes the data frame forwarding according to the MAC address table.

Layer Three switch: Layer three switching technology is the technology that combine routing technology with switching technology. After routing the first data stream, the

It will generate a map of the MAC address and IP address, and when the same data stream passes again, it will be directly from layer two through this table

routing, which eliminates the network delay caused by router routing and improves the efficiency of packet forwarding.

Routers: Routers work in the third layer of the OSI layer seven protocol, whose primary task is to receive packets from a network interface, based on

The destination address contained therein is decided to be forwarded to the next destination address.

2. What is the classification of routing protocols according to the application range? What are the classes of dynamic routing according to the algorithm?

1) Depending on the scope of application, routing protocols can be divided into two categories

The routing protocol within an as is called the Internal Gateway Protocol: the Internal Gateway routing protocol has the following: RIP-1, RIP-2, IGRP, EIGRP,

Is-is and OSPF;

The routing protocol between as is called the External Gateway Protocol External Gateway Protocol (also called Inter-Domain routing protocol): there are two types of inter-domain routing protocols: external

Gateway Protocol (EGP) and Border Gateway Protocol (BGP)

2) Dynamic routing according to the algorithm can be divided into: Distance vector routing protocol, link state routing protocol

Distance Vector Routing protocol: Select Route RIP,IGRP based on the number of routes that are routed from the source network to the target network

Link-State routing protocol: select route Ospf,is-is for each path from the source network to the target network

Day 03

1. What is HSRP? How does it work?

HSRP: Hot Standby Routing protocol

HSRP is a Cisco private protocol that ensures that user communication can be quickly and transparently restored when a network edge device or access link fails.

This provides redundant rows for the IP network. By using the same virtual IP address and virtual MAC address, two or more units on a LAN segment

Routers can serve as a virtual router for external use. HSRP enables Cisco routers within a group to monitor each other's running state.

2. What is the STP role?

STP: Spanning Tree protocol

Function: Logically disconnects the loop, prevents the broadcast storm from generating, when the line fails, the blocking interface is activated, resuming the communication, starting the backup line

's role.

Day 04

1. What is an ACL?

ACL (Access control list): Read the third layer, the fourth layer of Baotou information, according to predefined rules to filter the package.

2. Types and characteristics of access control lists

1) standard access control List

Filtering packets based on source IP address

List number is 1~99

2) Extended access Control List

Filter packets based on source IP address, destination IP address, specified protocol, port, etc.

List number is 100~199

3) Named access control List

Named access control lists allow names to be used instead of list numbers in standard and extended access control lists

Day 05

1. What is NAT? What are the implementation methods?

NAT (Network address translation): By translating the private IP address of the internal network into the world's only public IP address, the internal network can

To connect to an external network such as the Internet.

How NAT is implemented:

The corresponding relationship of the IP address is one-to-one, and is constant, with the help of the static transformation, it can realize some specific service in the external network.

Access to the service provider.

Dynamic conversion: The correspondence between IP addresses is indeterminate, but random, and all private addresses authorized to access the Internet can be randomly

Convert to any of the specified legitimate external IP addresses

Port multiplexing: By changing the source IP address and source port of the out-of-Office packet and port translation, all hosts on the internal network can

Share a legitimate IP address to achieve Internet access and conserve IP.

2. What is the specific idea of troubleshooting when you access http://www.tmooc.cn from a browser?

1.ipconfig View the current network configuration;

2.ping 127.0.0.1 Check whether the native TCP/IP protocol is installed successfully;

3.ping gateway address to verify connectivity to external network exits;

4.ping DNS server address verifies whether the intranet can find a DNS server;

5.ping domain name, verify that the DNS server is able to parse successfully (example: Ping www.tmooc.cn);

Cisco advanced Routing and switching for Linux systems