OSPF link regional accreditation and certification (Port Authentication) difference

In the configuration in OSPF,There are portions of the content certification,OSPF authentication is divided into two,They are

  • Based authentication area
  • Based authentication link (port)

The same time,Authentication mode can also be divided into two,One is plain text authentication,Another is the MD5 encrypted authentication。

Here we do not discuss OSPF encryption method,It is simply illustrative ofRegional links and similarities and differences between these two types of authentication。[……]

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OC: Optical Carrier Optical Carrier

OC standard fiber cable is commonly used in today's networks set of standards,Readily not hurt to look at memory。

Optical Carrier (OC) is determined at a level many SONET fiber optic network of a group of signal bandwidth。It is usually expressed as OC-n,among them,n is a multiplication factor,It indicates basic rate is 51.84 Mbit / s the number of times。Currently defined standards:
OC-1 — 51.8 4on[……]

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That point out the thing ARP RARP Inverse ARP and DHCP between

How do network also has a year,Speaking today, a fewAgreement with "arp" in accordance withSome confused old,So I come here to be a simple distinction。

First, that ARP (address resolution protocol):

This is not difficult to understand,arp protocol used in the computer artTao own MAC address and IP addressin the case of,It used to get the peer IP address corresponding to theMAC address。of course,cross[……]

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Cisco ip helper-address 详解

Some time ago I wroteA simple example Cisco routers DHCP and DHCP relay configuration,Article uses a command to achieve theDHCP forwarding,But this function is exactly how to achieve it? Now let's learn more about this command。

When the terminal equipment andDHCP serverWhen not on the same broadcast domain,Intermediate devices need to specify an address to be broadcast packet forwarded out,That needs to be sethelper_add[……]

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Packet Tracer 5.0 6.0 mutiuser multiplayer Internet Guide

Packet Tracer is an auxiliary company published by Ciscolearning tools,Learning courses for beginners to Cisco network design、Configuration、excludeNetwork failureProviding network simulation environment。Users cansoftwareofGraphical User InterfaceUse drag method to establish directNetwork topology,And provide detailed process data packets traveling in the network,Real-time observation of network operation。You can learn IOS configuration、Failure to exercise[……]

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A simple example Cisco routers DHCP and DHCP relay configuration

Today came across configurationDHCP relayThe problem,Suddenly I found that I had actually not noticed,Even sometimes do not know how to engage,And later I had to Google it very awkward ......,Now recorded as follows:

I was not on the map topology,Simple words to describe:



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About Cisco router% Pool globalnet in use, can not destroy solutions

In the study CCNA related courses NAT Network Address Translation content,When the practice often requires no out a dynamic NAT or PAT address pool

Cisco IOS NAT table as long as the provision of translation entries have included the address of the address pool,You will be able to modify or delete the address pool。

at this time,You enter

(config)# no ip nat pool pool_name


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