Netgear Router WGT624 V3 User Manual
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Network, Routing, Firewall, and Basics B-1 202-10090-01, April 2005 Appendix B Network, Routing, Firewall, and Basics This chapter provides an overview of IP networks, routing, and networking. Related Publications As you read this document, you may be directed to various RFC documents for further information. An RFC is a Request For Comment (RFC) published by the Internet Engineering Task Force (IETF), an open organization that defines the architecture and operation of the Internet. The RFC documents...
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Reference Manual for the 108 Mbps Wireless Firewall Router WGT624 v3 B-2 Network, Routing, Firewall, and Basics 202-10090-01, April 2005 Routing Information Protocol One of the protocols used by a router to build and maintain a picture of the network is the Routing Information Protocol (RIP). Using RIP, routers periodically update one another and check for changes to add to the routing table. The WGT624 v3 wireless router supports both the older RIP-1 and the newer RIP-2 protocols. Among other...
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Reference Manual for the 108 Mbps Wireless Firewall Router WGT624 v3 Network, Routing, Firewall, and Basics B-3 202-10090-01, April 2005 Figure 7-1: Three Main Address Classes The five address classes are: • Class A Class A addresses can have up to 16,777,214 hosts on a single network. They use an eight-bit network number and a 24-bit node number. Class A addresses are in this range: 1.x.x.x to 126.x.x.x. • Class B Class B addresses can have up to 65,354 hosts on a network. A Class B address uses a...
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Reference Manual for the 108 Mbps Wireless Firewall Router WGT624 v3 B-4 Network, Routing, Firewall, and Basics 202-10090-01, April 2005 This addressing structure allows IP addresses to uniquely identify each physical network and each node on each physical network. For each unique value of the network portion of the address, the base address of the range (host address of all zeros) is known as the network address and is not usually assigned to a host. Also, the top address of the range (host address...
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Reference Manual for the 108 Mbps Wireless Firewall Router WGT624 v3 Network, Routing, Firewall, and Basics B-5 202-10090-01, April 2005 Subnet addressing allows us to split one IP network address into smaller multiple physical networks known as subnetworks. Some of the node numbers are used as a subnet number instead. A Class B address gives us 16 bits of node numbers translating to 64,000 nodes. Most organizations do not use 64,000 nodes, so there are free bits that can be reassigned. Subnet...
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Reference Manual for the 108 Mbps Wireless Firewall Router WGT624 v3 B-6 Network, Routing, Firewall, and Basics 202-10090-01, April 2005 The following table lists the additional subnet mask bits in dotted-decimal notation. To use the table, write down the original class netmask and replace the 0 value octets with the dotted-decimal value of the additional subnet bits. For example, to partition your Class C network with subnet mask 255.255.255.0 into 16 subnets (4 bits), the new subnet mask becomes...
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Reference Manual for the 108 Mbps Wireless Firewall Router WGT624 v3 Network, Routing, Firewall, and Basics B-7 202-10090-01, April 2005 • So that hosts recognize local IP broadcast packets When a device broadcasts to its segment neighbors, it uses a destination address of the local network address with all ones for the host address. In order for this scheme to work, all devices on the segment must agree on which bits comprise the host address. • So that a local router or bridge recognizes which...
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Reference Manual for the 108 Mbps Wireless Firewall Router WGT624 v3 B-8 Network, Routing, Firewall, and Basics 202-10090-01, April 2005 The following figure illustrates a single IP address operation. Figure 7-3: Single IP Address Operation Using NAT This scheme offers the additional benefit of firewall-like protection because the internal LAN addresses are not available to the Internet through the translated connection. All incoming inquiries are filtered out by the router. This filtering can...
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Reference Manual for the 108 Mbps Wireless Firewall Router WGT624 v3 Network, Routing, Firewall, and Basics B-9 202-10090-01, April 2005 If a device sends data to another station on the network and the destination MAC address is not yet recorded, ARP is used. An ARP request is broadcast onto the network. All stations on the network receive and read the request. The destination IP address for the chosen station is included as part of the message so that only the station with this IP address responds to...
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Reference Manual for the 108 Mbps Wireless Firewall Router WGT624 v3 B-10 Network, Routing, Firewall, and Basics 202-10090-01, April 2005 IP Configuration by DHCP When an IP-based local area network is installed, each PC must be configured with an IP address. If the PCs need to access the Internet, they should also be configured with a gateway address and one or more DNS server addresses. As an alternative to manual configuration, there is a method by which each PC on the network can automatically...