Hitless Layer 2 Os Upgrade - Brocade Communications Systems PowerConnect B-RX Release Note

Hitless Layer 2 OS upgrade

Hitless O/S upgrades are supported for Layer 2 switching and Layer 2 protocols only. See the Upgrading
Software Images and Configuration Files chapter in the BigIron RX Installation Guide for additional
information. The hitless O/S Layer 2 upgrade allows for upgrading the software in a system between two
releases of the O/S, which support this functionality and have compatible data structures. A hitless O/S
Layer 2 downgrade may also be supported if the current and target code releases have compatible data
structures. From time to time, it may become necessary when enhancing the software or adding new
features to change or add data structures making releases incompatible. In these cases, an upgrade or
downgrade will not be hitless, and will fall back to using the regular Brocade upgrade process – relying
on fast reboot.
When performing a hitless O/S Layer 2 upgrade or downgrade, use the following guidance:

Hitless O/S Layer 2 upgrade or downgrade is not supported in 2.3.00 or earlier.

Hitless O/S Layer 2 upgrade support is in 2.3.00a and higher patch releases (unless indicated
otherwise in the target software's release notes).

Hitless upgrade maintains forwarding states and control plane functionality of the active software
from which you are upgrading (i.e. 2.3.00a to 2.3.00d would only maintain the functionality
supported by 2.3.00a).

Hitless downgrades are recommended only between compatible patch releases of a feature release
such as between 2.3.00b to 2.3.00a (to ensure the higher release has no conflicting functional
enhancements that do not exist in the lower release).

Due to the PBIF change introduced in patch release version 02.3.00e and version 02.3.00f, users
cannot perform hitless upgrades from earlier 02.3.00 versions or 02.3.00g or higher versions. For
information on Hitless Upgrades refer to the "Hitless OS Upgrade" section in the BigIron RX
Installation Guide.

Due to Internal changes introduced in patch release version 02.4.00d ,hitless upgrade is not supported
onto 02.4.00b and hitless downgrade is not supported from 02.4.00d.

The Hitless upgrade feature is not supported on release 02.5.00b to 02.5.00c for the BigIron RX-32
only. It is supported on all other BigIron RX devices.
Using this feature, you can upgrade the Multi-Service IronWare software without a loss of service or
disruption in the following supported functions and protocols:

All ports and links remain operational

TOS-based QoS

Layer-2 Switching

Layer-2 Protocols:

MRP

STP

VSRP

RSTP

MSTP
IronWare Software Release 02.7.02a for Brocade BigIron RX Series Swtches
Release Notes v 1.0 Page 30 of 46