24IPv4 RoutingThe Dell Networking Operating System (OS) supports various IP addressing features. This chapter describes the basics of domainname service (DNS), address resolution protocol (ARP), and routing principles and their implementation in the Dell Networking OS.IP Feature DefaultDNS DisabledDirected Broadcast DisabledProxy ARP EnabledICMP Unreachable DisabledICMP Redirect DisabledIP AddressesDell Networking OS supports IP version 4 (as described in RFC 791), classful routing, and variable length subnet masks (VLSM).With VLSM, you can configure one network with different masks. Supernetting, which increases the number of subnets, is alsosupported. To subnet, you add a mask to the IP address to separate the network and host portions of the IP address.At its most basic level, an IP address is 32-bits composed of network and host portions and represented in dotted decimal format.For example, 00001010110101100101011110000011 is represented as 10.214.87.131.For more information about IP addressing, refer to RFC 791, Internet Protocol.Implementation InformationYou can configure any IP address as a static route except IP addresses already assigned to interfaces.NOTE: Dell Networking OS supports 31-bit subnet masks (/31, or 255.255.255.254) as defined by RFC 3021. This featureallows you to save two more IP addresses on point-to-point links than 30-bit masks. Dell Networking OS supports RFC3021 with ARP.NOTE: Even though Dell Networking OS listens to all ports, you can only use the ports starting from 35001 for IPv4traffic. Ports starting from 0 to 35000 are reserved for internal use and you cannot use them for IPv4 traffic.Configuration Tasks for IP AddressesThe following describes the tasks associated with IP address configuration.Configuration tasks for IP addresses includes:• Assigning IP Addresses to an Interface (mandatory)• Configuring Static Routes (optional)• Configure Static Routes for the Management Interface (optional)For a complete listing of all commands related to IP addressing, refer to the Dell Networking OS Command Line Interface ReferenceGuide.IPv4 Routing 403
