1 course number presentation_id © 2001, cisco systems, inc. all rights reserved. cisco 7500 high...

1Course NumberPresentation_ID © 2001, Cisco Systems, Inc. All rights reserved.© 2001, Cisco Systems, Inc. All rights reserved.© 2001, Cisco Systems, Inc. All rights reserved.

Cisco 7500 High Availability

Presentation_ID © 2001, Cisco Systems, Inc. All rights reserved. 2Presentation_ID © 2001, Cisco Systems, Inc. All rights reserved. 2Presentation_ID © 2001, Cisco Systems, Inc. All rights reserved. 2

Cisco 7500 Before HA – High System Availability

• Cold standby solution before HA

• Active RSP and Standby RSP Previously referred to as Master RSP and Slave RSP

• Upon failure, system resets and previous Standby RSP becomes Active

• Allows automatic system recovery

• Can take 8 to 10 minutes depending on configuration


Cisco 7500 High Availability Features

• Single Line Card Reload (SLCR)

• Route Processor Redundancy (RPR)

• Fast Software Upgrade (FSU)

• Route Processor Redundancy Plus (RPR+)

• IOS High Availability –

Stateful SwitchOver & Non-Stop Forwarding


Single Line Card Reload

Route Switch Processors

VIPVIPVIP VIP

• When a VIP crashes, it is isolated from the rest of the system and reloaded

• The rest of the system continues forwarding packets with little interruption

• SLCR supports VIP4, VIP2, VIP-based IP, and legacy IP

• SLCR can handle up to two simultaneous line card crashes

Rest of system only minimally

affected

Crash isolated, line card recovery

accelerated


Single Line Card Reload (cont.)

• SLCR is supported in 12.0(13)S, 12.0(14)ST, 12.1(4)T and 12.1(5)E

• SLCR is disabled by default, and needs to be manually configured

• SLCR can be configured with the following command

Router(config)# service single-slot-reload-enable


Route Processor Redundancy


VIPVIPVIP VIP

• Accelerates switchover to Standby RSP when Active RSP fails

• Same IOS image on Active and Standby RSPs

• Full software image pre-initialized on Standby RSP, which takes over from Active RSP (after a crash, redundancy force-switchover, or OIR removal of Active RSP)

• Switchover resets all line cards and parses config from NVRAM

• Reduces recovery time from 8-10 minutes (HSA) to 4-5 minutes

• Supports RSP2, RSP4/RSP4+, and RSP8

Standby RSP pre-initialized for speedy cutover


• RPR is supported in 12.0(16)ST

• RPR requires two RSP8s or any combination of RSP2s and RSP4s

RSP2/2, RSP2/4, RSP4/4, RSP8/8

Same RSP combination support as HSA

• Default redundancy mode is HSA, so RPR needs to be manually configured

Route Processor Redundancy (cont.)


RPR Configuration Commands

• Router(config)# hw-module slot<RSP slot#> image <file-spec>

specifies IOS image for each RSP in RPR re-initializations, required for both RSPs, no tftp/rcp, not related to “boot system flash“ command which is used at reload

• Router(config)# redundancy

enters redundancy mode

• Router(config-r)# mode rpr

sets redundancy mode to RPR

• Router(config)# slave auto-sync config

just in case auto-sync (on by default) has been disabled

• Router# copy running-config startup-config

saves configuration

• Router# hw-module sec-cpu reset (slave reload also works)

resets and reloads Standby RSP with specified image


Fast Software Upgrade


VIPVIPVIP VIP

• An “application” of RPR to accelerate software upgrade

• Preload Standby RSP with upgraded IOS image, initialize, and switchover

• Reduces downtime of SW upgrade operation to 4-5 minutes

• Requires the Active and Standby images to be FSU-compatible

Standby RSP loaded with new software image


FSU Configuration Commands





• Router(config-r)# mode rpr

sets redundancy mode to RPR, there is no FSU mode




saves configuration


resets and reloads, will flag error if Standby image not FSU-compatible with Active

• Router# redundancy force-switchover

forces switchover to Standby RSP, this command works on rpr, rpr-plus, and sso


Route Processor Redundancy +

• Further accelerates switchover to Standby RSP

• Same IOS image on Active and Standby RSPs

• Full software image pre-initialized on Standby RSP, which takes over from Active RSP (after a crash, redundancy force-switchover, or OIR removal of Active RSP)

• Running-config is sync’d on Standby RSP, switchover does not reset line cards and does not parse config from NVRAM

• Reduces recovery time down to 30-40 seconds

• Supports RSP2, RSP4/RSP4+, and RSP8


VIPVIPVIP VIP

Standby RSP pre-initialized for speedy cutover

No need to reload the VIPs


• RPR+ is supported in 12.0(19)ST1

• RPR requires two RSP8s or any combination of RSP2s and RSP4s

RSP2/2, RSP2/4, RSP4/4, RSP8/8

Same RSP combination support as HSA

• Default redundancy mode is HSA, so RPR+ needs to be manually configured

• Standby RSP in RPR+ keeps a running-config which is auto-sync’d to running-config of Active RSP to further accelerate switchover

• RPR+ requires same image on Active and Standby RSPs, otherwise it will fall back to RPR even if configured as RPR+

• RPR+ supports VIPs, and up to two legacy IPs if SLCR is configured (the legacy IPs will be reset by RPR+), otherwise it falls back to RPR

• Pulling out an Active RSP to force a switchover will fall back to RPR

Route Processor Redundancy+ (cont.)


RPR+ Configuration Commands





• Router(config-r)# mode rpr-plus

sets redundancy mode to RPR+




saves configuration


resets and reloads Standby RSP with specified image


• Based on RPR+

• Standby RSP in SSO maintains the states of key routing and interface protocols and more

BGP, OSPF, IS-IS, PPP, ATM, FR, HDLC, NAT, …..

• To be available in 12.0(22)S which will support all HA features



• Router(config-r)# mode sso

sets redundancy mode to SSO

• NSF requires routing peers to cooperate in maintaining routing protocol states on the network

Stateful SwitchOver & Non-Stop Forwarding


To Verify High Availability Operation

Router# show redundancy

Operating mode is rpr-plus

redundancy mode rpr-plus

hw-module slot 2 image disk0:rsp-pv-mz

hw-module slot 3 image disk0:rsp-pv-mz

The system total uptime since last reboot is ...

The system has experienced 2 switchovers.

The system has been active (become master) for ...

Reason for last switchover:User forced.

Note: It takes a few minutes after resetting the Standby RSP for it to become fully initialized and sync’d to function in the configured redundancy mode.


• Make sure the Standby RSP config is sync’d with the Active RSP

• Always do hw-module sec-cpu reset after changing HA modes

• redundancy force-switchover will automatically check that the startup-configs on the Active and Standby RSPs are the same, otherwise it will issue a warning message/prompt

• Use of Y-cable for console access is recommended

• Direct console access to Standby RSP works, but do not issue any commands or config changes to Standby RSP

• For crash diagnosis, crashinfo can be obtained from bootflash on standby (previously active) RSP after switchover

• Wait one minute between OIR operations

Notes on HA Operations

1 course number presentation_id © 2001, cisco systems, inc. all rights reserved. cisco 7500 high...

Documents

cisco systems

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previous standby rsp

rsp8 standby rsp

ha active rsp

slave rsp

master rsp

rsp combination support