Admin Guide
Table Of Contents
- Contents
- Chapter 1: Introduction
- Chapter 2: New in this document
- Chapter 3: Basic administration
- Chapter 4: System startup fundamentals
- Chapter 5: Boot parameter configuration using ACLI
- Chapter 6: Run-time process management using ACLI
- Chapter 7: Chassis operations
- Chassis operations fundamentals
- Chassis operations configuration using ACLI
- Enabling jumbo frames
- Configuring port lock
- Configuring SONMP
- Viewing the topology message status
- Associating a port to a VRF instance
- Configuring an IP address for the management port
- Configuring Ethernet ports with Autonegotiation
- Enabling channelization
- Configuring serial management port dropping
- Controlling slot power
- Enabling or disabling the USB port
- Chassis operations configuration using EDM
- Editing system information
- Editing chassis information
- Configuring system flags
- Configuring channelization
- Configuring basic port parameters
- Viewing the boot configuration
- Configuring boot flags
- Enabling Jumbo frames
- Configuring the date and time
- Associating a port to a VRF instance
- Configuring CP Limit
- Configuring an IP address for the management port
- Editing the management port parameters
- Configuring the management port IPv6 interface parameters
- Configuring management port IPv6 addresses
- Auto reactivating the port of the SLPP shutdown
- Editing serial port parameters
- Enabling port lock
- Locking a port
- Viewing power information
- Viewing power status on VSP 8400
- Viewing fan information
- Viewing topology status information
- Viewing the topology message status
- Configuring a forced message control pattern
- Chapter 8: Hardware status using EDM
- Chapter 9: Domain Name Service
- Chapter 10: Licensing
- Chapter 11: Network Time Protocol
- Chapter 12: Secure Shell
- Secure Shell fundamentals
- Secure Shell configuration using ACLI
- Downloading the software
- Enabling the SSHv2 server
- Changing the SSH server authentication mode
- Setting SSH configuration parameters
- Verifying and displaying SSH configuration information
- Connecting to a remote host using the SSH client
- Generating user key files
- Managing an SSL certificate
- Disabling SFTP without disabling SSH
- Enabling SSH rekey
- Configuring SSH rekey data-limit
- Configuring SSH rekey time-interval
- Displaying SSH rekey information
- Downgrading or upgrading from releases that support different key sizes
- Secure Shell configuration using Enterprise Device Manager
- Chapter 13: System access
- System access fundamentals
- System access configuration using ACLI
- Enabling ACLI access levels
- Changing passwords
- Configuring an access policy
- Specifying a name for an access policy
- Allowing a network access to the switch
- Configuring access policies by MAC address
- System access security enhancements
- Displaying the boot config flags status
- Enabling enhanced secure mode
- Creating accounts for different access levels
- Deleting accounts in enhanced secure mode
- Configuring a password for a specific user
- Returning the system to the factory defaults
- Configuring the password complexity rule
- Configuring the password length rule
- Configuring the change interval rule
- Configuring the reuse rule
- Configuring the maximum number of sessions
- Configuring the maximum age rule
- Configuring the pre- and post-notification rule
- System access configuration using EDM
- Chapter 14: ACLI show command reference
- Access, logon names, and passwords
- Basic switch configuration
- Current switch configuration
- CLI settings
- Ftp-access sessions
- Hardware information
- NTP server statistics
- Power summary
- Power information for power supplies
- System information
- System status (detailed)
- Telnet-access sessions
- Users logged on
- Port egress COS queue statistics
- CPU queue statistics
- Chapter 15: Port numbering and MAC address assignment reference
- Chapter 16: Supported standards, RFCs, and MIBs
- Glossary
NTP system implementation model
NTP is based on a hierarchical model that consists of a local NTP client that runs on the switch and
on remote time servers. The NTP client requests and receives time information from one or more
remote time servers. The local NTP client reviews the time information from all available time
servers and synchronizes its internal clock to the time server whose time is most accurate. The NTP
client does not forward time information to other devices that run NTP.
Two types of time servers exist in the NTP model: primary time servers and secondary time servers.
A primary time server is directly synchronized to a primary reference source, usually a wire or radio
clock that is synchronized to a radio station that provides a standard time service. The primary time
server is the authoritative time source in the hierarchy, meaning that it is the one true time source to
which the other NTP devices in the subnet synchronize their internal clocks.
A secondary time server uses a primary time server or one or more secondary time servers to
synchronize its time, forming a synchronization subnet. A synchronization subnet is a self-
organizing, hierarchical master-backup configuration with the primary servers at the root and
secondary servers of decreasing accuracy at successive levels.
The following figure shows NTP time servers forming a synchronization subnet.
Figure 2: NTP time servers forming a synchronization subnet
In the NTP model, the synchronization subnet automatically reconfigures in a hierarchical primary-
secondary configuration to produce accurate and reliable time, even if one or more primary time
servers or the path between them fails. This feature applies in a case in which all the primary
servers on a partitioned subnet fail, but one or more backup primary servers continue to operate. If
all of the primary time servers in the subnet fail, the remaining secondary servers synchronize
among themselves.
Network Time Protocol
January 2017 Administering Avaya VSP 7200 Series and 8000 Series 134
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