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NAT Virtual Interface
Scenario: After passing the CCNA exam you feel like you could do anything with NAT. You just started at a new job as a junior network engineer but to your surprise the router you are working on doesn’t…
Read More »NAT Overlapping Networks
Scenario: Fruity international has bought Juicy Corporate and is merging the companies into a new one called “Fruity Juicy”. You are the network engineer responsible for the network migration. Unfortunately both networks are using the same address space…
Read More »Static PAT (Port Forwarding)
Scenario: You are a trainee for a large international website covering a wide range of topics on automobiles. You are using NAT and PAT for connectivity to the Internet but you also have a number of hosts on…
Read More »NAT and Route-Map
Scenario: Your network has two connections to the outside world. One is used for the Internet and the other one connects to a partner. You are using NAT to translate the IP addresses of your LAN but you…
Read More »ICMP Router Discovery Protocol (IRDP)
Scenario: As the senior network engineer for “Groceries ‘r’ Us” you are responsible for all routing within the company. The network you are running is fairly old and doesn’t support any fancy routing protocols. Your routers seem to…
Read More »IP Service Level Agreement (SLA)
Scenario: As the senior network engineer for “Groceries ‘r’ Us” you are responsible for all routing within the company. Every now and then you have links that are still in the up/up state but you are unable to…
Read More »DHCP Authorized ARP
Scenario: You work as a network engineer for a Hotel offering Internet access for a hourly rate. Recently you notice that some customers have been spoofing MAC and IP addresses to get free access by pretending they are…
Read More »DHCP Proxy
Scenario: You used to have a DHCP server for each VLAN but this wasn’t much of a scalable solution. You decide to get rid of all the DHCP servers and install a single DHCP server in the datacenter….
Read More »DHCP Server On-Demand Addres Pool
Scenario: Your network has many serial links running PPP. You heard some good things about DHCP and how you can create on-demand pools using IPCP. Let’s see if it works the way you expect… Goal: Configure both routers…
Read More »DHCP Relay
Scenario: You used to have a DHCP server for each VLAN but this wasn’t much of a scalable solution. You decide to get rid of all the DHCP servers and install a single DHCP server in the datacenter….
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