Extreme Networks ExtremeWare XOS Guide Manual page 665

S (Continued)
SSH
SSL
standard mode
STP
STPD
STPD mode
stub areas
ExtremeWare XOS 11.3 Concepts Guide
Secure Shell, sometimes known as Secure Socket Shell, is a UNIX-
based command interface and protocol of securely gaining access to a
remote computer. With SSH commands, both ends of the client/server
connection are authenticated using a digital certificate, and passwords
are protected by being encrypted. At Extreme Networks, the SSH is a
separate software module, which must be downloaded separately.
(SSH is bundled with SSL in the software module.)
Secure Sockets Layer. SSL is a protocol for transmitting private
documents using the Internet. SSL works by using a public key to
encrypt data that is transferred over the SSL connection. SSL uses the
public-and-private key encryption system, which includes the use of a
digital certificate. At Extreme Networks, SSL is bundled with the SSH
software module, which must be downloaded separately. SSL used for
other applications than SSH, CNA at Extreme Networks for example.
Use ESRP standard mode if your network contains switches running
ExtremeWare and switches running ExtremeWare XOS, both
participating in ESRP.
Spanning Tree Protocol. STP is a protocol, defined in IEEE 802.1d,
used to eliminate redundant data paths and to increase network
efficiency. STP allows a network to have a topology that contains
physical loops; it operates in bridges and switches. STP opens certain
paths to create a tree topology, thereby preventing packets from
looping endlessly on the network. To establish path redundancy, STP
creates a tree that spans all of the switches in an extended network,
forcing redundant paths into a standby, or blocked, state. STP allows
only one active path at a time between any two network devices (this
prevents the loops) but establishes the redundant links as a backup if
the initial link should fail. If STP costs change, or if one network
segment in the STP becomes unreachable, the spanning tree algorithm
reconfigures the STP topology and re-establishes the link by activating
the standby path.
Spanning Tree Domain. An STPD is an STP instance that contains one
or more VLANs. The switch can run multiple STPDs, and each STPD
has its own root bridge and active path. In the Extreme Networks
implementation of STPD, each domain has a carrier VLAN (for
carrying STP information) and one or more protected VLANs (for
carrying the data).
The mode of operation for the STPD. The two modes of operation are:
802.1d—Compatible with legacy STP and other devices using the
●
IEEE 802.1d standard.
802.1w—Compatible with Rapid Spanning Tree (RSTP).
●
In OSPF, a stub area is connected to only one other area (which can be
the backbone area). External route information is not distributed to
stub areas.
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