Alcatel-Lucent 060321-10, Rev. B, Cli Reference Manual

Page: 419 / 2354

OmniSwitch CLI Reference Guide March 2011 page 10-1
10 IP Commands
This chapter details Internet Protocol (IP) commands for the switch. IP is a network-layer (Layer 3)
protocol that contains addressing information and some control information that enables packets to be
forwarded. IP is documented in RFC 791 and is the primary network-layer protocol in the Internet
protocol suite. Along with the Transmission Control Protocol (TCP), IP represents the heart of the Inter-
net protocols.
IP is enabled on the switch by default and there are few options that can, or need to be, configured. This
chapter provides instructions for basic IP configuration commands. It also includes commands for several
Layer 3 and Layer 4 protocols that are associated with IP:
•
Address Resolution Protocol (ARP)—Used to match the IP address of a device with its physical
(MAC) address.
•
Internet Control Message Protocol (ICMP)—Specifies the generation of error messages, test packets,
and informational messages related to IP. ICMP supports the
ping command used to determine if hosts
are online.
•
Transmission Control Protocol (TCP)—A major data transport mechanism that provides reliable,
connection-oriented, full-duplex data streams. While the role of TCP is to add reliability to IP, TCP
relies upon IP to do the actual delivering of datagrams.
•
User Datagram Protocol (UDP)—A secondary transport-layer protocol that uses IP for delivery. UDP
is not connection-oriented and does not provide reliable end-to-end delivery of datagrams. But some
applications can safely use UDP to send datagrams that do not require the extra overhead added by
TCP.
The IP commands also include protection from Denial of Service (DoS) attacks. The goal of this feature is
to protect a switch from well-known DoS attacks and to notify the administrator or manager when an
attack is underway. Also, notifications can be sent when port scans are being performed.
Note. Packets can be forwarded using IP if all devices are on the same VLAN, or if IP interfaces are
created on multiple VLANs to enable routing of packets. However, IP routing requires one of the IP rout-
ing protocols: Routing Information Protocol (RIP) or Open Shortest Path First (OSPF). See the following
chapters for the appropriate CLI commands:
Chapter 13, “RIP Commands,” Chapter 17, “OSPF
Commands.” For more information on VLANs and RIP see the applicable chapter(s) in the Configuration
Guide. For more information on OSPF, see the “Configuring OSPF” chapter in the OmniSwitch 10K
Advanced Routing Configuration Guide .