cisco certification ccnp

cisco certification ccnp.Class C 192.168.0.0.192.168.255.255 256 254Good network planning requires a good understanding of the various private IP address spaces (let's say, a good knowledge of the number of hosts and subnets available for each type of private IP address). Careful planning and preparation can save a lot of time in the event of future changes.Tip: The white paper "ASecurity-Oriented ApproachtoIP Addressing" documents a number of tips related to developing and designing an IP addressing scheme for your network.1. port address translation plants. a feature called port address translation (PAT) is typically enabled on the firewall. This feature is a type of NAT(,il feature that allows multiple devices on a protected internal network to access (or be accessed by) the external network as a single IP address plus a different Layer 4 port number. This IP address is usually the public IP address on the firewall, but can of course be any other available public IP address. Figure 2.3 shows how PAT works. As shown in Figure 2-3, within the trusted network (labeled with Inside), there are multiple hosts with IP subnets from10.10.10.0/24. The firewall provides the PAT function for the hosts in the trusted network to convert the IP address 10.10.10.x to the public address of the local machine (209.165.200.228).0 In this example, Host A issues TCP source port numbers of 1024, 1024, 1024, and 1024.2.2 Network Security Systems 117However, an Intrusion Prevention System (IPS) device not only detects all of the above security threats, but also drops malicious packets inline. When an IPS device first goes live within a network, it is first deployed in promiscuous mode (monitored mode). The purpose of doing so is to first assess the impact of introducing IPS devices on the network infrastructure and operations. Then, deploy the IPS in inline mode to block any malicious traffic within the network without disrupting service.A packet with a destination port of 80 goes to a web server on an unprotected network (marked with Outside). The firewall first takes the source IP address of the packet, 10.10.10.8 (the real IP address of Host A)118 Chapter 2 Network Security Appliances and Cloud Services10.10.10.3 >PAT >Translated IP address 209.165.200.228