System Management
7950 SR OS Basic System Configuration Guide
Page 233
configurable.
•
BGP default session timeout is approximately 120 seconds. The timeout intervals are
configurable.
Therefore, router software has to recover faster than the specified time interval to maintain up
time.
Configuration Redundancy
Features configured on the active device CPM are saved on the standby CPMas well. When the
active device CPM fails, these features are brought up on the standby device CPM that takes over
the mastership.
Even with modern modular and stable software, the failure of route processor hardware or
software can cause the router to reboot or cause other service impacting events. In the best
circumstances, failure leads to the initialization of a redundant route processor, which hosts the
standby software configuration, to become the active processor. The following options are
available.
•
Warm standby — The router image and configuration is already loaded on the standby
route processor. However, the standby could still take a few minutes to become effective
since it must first re-initialize connections by bringing up Layer 2 connections and Layer
3 routing protocols and then rebuild routing tables.
•
Hot standby — The router image, configuration, and network state is already loaded on
the standby and it receives continual updates from the active route processor and the
swapover is immediate. However, hot standby affects conventional router performance as
more frequent synchronization increases consumption of system resources. Newer
generation service routers, like the SR OS routers, address this issue because they already
have extra processing built into the system.
Component Redundancy
7950 SR-Series component redundancy is critical to reduce MTTR for the system and primarily
consists of the following routerfeatures:
•
Dual route processor modules — For a highly available architecture, redundant route
processors (RPs) or Control Processor Modules() are essential. The route processor
calculates the most efficient route to an Internet destination and communicates the best
path information to peer routers. Rapid information synchronization between the primary
and secondary route processor is crucial to minimize recovery time.
•
switch fabric (SFM) redundancy — Failover to the backup switch fabric within a
minimum time interval, preferably with no loss of traffic.
Содержание 7950 XRS Series
Страница 8: ...Page 8 7950 SR OS Basic System Configuration Guide List of Tables...
Страница 10: ...Page 10 7950 SR OS Basic System Configuration Guide List of Figures...
Страница 14: ...Preface Page 14 7950 SR OS Basic System Configuration Guide...
Страница 46: ...VI Editor Page 46 7950 SR OS Basic System Configuration Guide...
Страница 76: ...File Management Tasks Page 76 7950 SR OS Basic System Configuration Guide...
Страница 78: ...File Command Reference Page 78 7950 SR OS Basic System Configuration Guide...
Страница 92: ...Basic Command Reference Page 92 7950 SR OS Basic System Configuration Guide show system candidate...
Страница 172: ...Basic CLI Commands Page 172 7950 SR OS Basic System Configuration Guide...
Страница 184: ...Configuration Notes Page 184 7950 SR OS Basic System Configuration Guide...
Страница 214: ...DNS Configuration Commands Page 214 7950 SR OS Basic System Configuration Guide...
Страница 220: ...Show Commands Page 220 7950 SR OS Basic System Configuration Guide...
Страница 494: ...System Commands Page 494 7950 SR OS Basic System Configuration Guide...
Страница 500: ...Standards and Protocols Page 500 Standards and Protocols...
Страница 502: ...Index Page 502 7950 SR OS Basic System Configuration Guide system parameters 252 system time elements 256 timing 294...