User guide

September 2009
Page 46 of 79 OmniSwitch 6400/6850/6855/9000/9000E—Release 6.4.2.R01
RFC 1256. Using RDP, hosts attached to multicast or broadcast networks send solicitation messages
when they start up. Routers respond to solicitation messages with an advertisement message that
contains the router IP addresses. In addition, routers send advertisement messages when their RDP
interface becomes active and then subsequently at random intervals.
Routing Protocol Preference
Specifying a routing protocol preference is supported. This is done by configuring a weight for each
routing protocol (including static routes) to control which entry to prefer when two entries exist from
different sources. By default, local routes always have precedence.
RRSTP
Ring Rapid Spanning Tree Protocol (RRSTP) is complimentary to either the Rapid Spanning Tree
(RSTP) or the Multiple Spanning Tree Protocol (MSTP) but is designed to enhance convergence time
in a ring configuration when a link failure occurs. Note that RRSTP is supported only in a ring
topology where switches are connected point to point. In addition, there can be no alternate
connections for the same instance between any two switches within a ring topology.
RRSTP reduces convergence time by finding the bridge that hosts the alternate (ALT) port and
immediately changing the ALT port state to forwarding without altering the port state. This process
quickly enables the data path. The RRSTP frame travels from the point of failure to the ALT port in
both directions. The MAC addresses corresponding to the ports in the ring are flushed to make the data
path convergence time much faster. While RRSTP is already reacting to the loss of connectivity, the
standard BPDU carrying the information about the link failure is processed in normal fashion at each
hop. When this BPDU reaches the bridge whose ALT port is now in the "ALT FWD" state, due to
RRSTP frame processing, it updates the state of the two ports in the ring as per the STP standard.
RRSTP is only supported when the switch is configured in Flat mode (RRSTP or MSTP).
Secure Copy (SCP)
The scp CLI command is available for copying files in a secure manner between hosts on the network.
The scp utility performs encrypted data transfers using the Secure Shell (SSH) protocol. In addition,
scp uses available SSH authentication and security features, such as prompting for a password if one is
required.
Secure Shell (SSH)
The Secure Shell feature provides a secure mechanism that allows you to log in to a remote switch, to
execute commands on a remote device, and to move files from one device to another. Secure Shell
provides secure, encrypted communications even when your transmission is between two untrusted
hosts or over an unsecure network.
The OmniSwitch includes both client and server components of the Secure Shell interface and the
Secure Shell FTP file transfer protocol. SFTP is a subsystem of the Secure Shell protocol. All Secure
Shell FTP data are encrypted through a Secure Shell channel.
When used as an SSH Server, the following SSH Software is supported on the indicated operating
systems:
SSH Software Supported Operating Systems
OpenSSH Sun Solaris, Mac OSX, Linux Red Hat
F-Secure Sun Solaris, Win 2000, Win XP
SSH-Communication Sun Solaris, Win 2000, Win XP, Linux Red Hat
PuTTY Win 2000, Win XP
MAC-SSH Mac OSX