On the switch，There are three commonly used configuration mode，Respectively Access (Access)，Trunk (trunk or trunk) as well as Hybrid (Hybrid)，These three interfaces operating mode determines the corresponding interface for processing the attitude data packets on the switch。Nowadays，Routing to elaborate on these three models。
Since the switch has divided the virtual LAN VLAN function is，So it[……]
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。
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[……]
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[……]
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[……]
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：
R1(f0/1)————-(f0/1)R2(f0/0)——S1——PC0
[……]
—————————（=。= It is not a test of a little late ah ......)
In a recent study CCNA routing Well，To practice what deployment routes，The first problem encountered is actually get rid of the password on the route ......
This simple，Minute minute[……]
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
[……]