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Date: Thu, 29 Jul 2003 12:09:39 -0500 (EST)
From: ImageStream Support
Subject: Enterprise Linux 4.1.6 for routers available

Version 4.1.6 of ImageStream's Enterprise Linux is now available as an
general availability (GA) release for all ImageStream router customers.

This software release is provided at no charge to all ImageStream customers.
Version 4.1.6 is recommended for all customers, and is highly recommended
for all customers who wish to upgrade to the latest available software release.


This release note documents commands and features added between Version
4.1.4 and Version 4.1.6.


New Features in Version 4.1.6

SoftATM (Software-based ATM) Added

Version 4.1.6 includes SAND 3.5.21.  This version of SAND includes support for software-based
ATM and IMA.  604, 608 and 530 series T1/E1/J1 cards can be configured for ATM and inverse
multiplexing.  SAND processes and performs segmentation and reassembly on AAL5 cells at wirespeed
up to 4 ports per IMA group.  Non-IMA ATM circuits and multiple IMA groups can be configured as

GateD Checks Protocol Status Before Adding Routes

ImageStream's GateD release now checks protocol status on SAND interfaces.  When protocol
status is down, the version of GateD included in Version 4.1.6 will stop advertising routes
for the interface.  Previous versions of GateD did not have the ability to differentiate
between protocol status and hardware status.

Serial Console Performance Improved

Version 4.1.6 implements kernel console thread to manage the flow of messages to serial consoles.
Previous versions of Enterprise Linux experienced impaired performance when logging messages to a
serial console, or when logging to a console port that was not connected.  Version 4.1.6
maintains a threaded buffer that ensures that other processes on the router are not affected by

Failsafe Support Updated

Version 4.1.6 includes an updated Failsafe image.  The Failsafe boot option contains additional
safeguards to assist in recovery of failed upgrades, lost passwords or other misconfigurations.
The new Failsafe image contains a complete, standalone image that does not require any support
or files from the main router distribution image.

NetFlow/sFlow Probe Added

Version 4.1.6 contains a NetFlow probe service.  This new service allows traffic flows to be
exported to any NetFlow Version 5 collector or sFlow collector.  The probe is a highly scalable
passive monitor that collects detailed information about traffic flows on any router interface.
The probe collects and integrates information across all levels of the protocol stack, enabling
an accurate understanding of network performance, congestion management, protocol interaction,
routing optimization, and audit trail analysis of network activity.

Simple BGP Configuration Script Updated

The simple BGP peer configuration script included with ImageStream's GateD software has been
updated in Version 4.1.6.  The script now prompts for more information and uses default values
if information is omitted from the script entries.

IPTables Quota Supported

The IPTables firewall software included in Version 4.1.6 now supports the use of quotas.  The
addition of quotas allows for rules to match after a certain traffic threshhold has been passed.
This functionality includes the ability to discontinue service to a particular IP address or
network block after a quota has been reached.

Backup And Restore Scripts Support Any Filename

The backup and restore scripts used to manage configuration on ImageStream routers have been
updated.  In previous versions, the configuration file created and used by the backup and
restore scripts was named ISisConfig.tar.gz.  In Version 4.1.6, any filename may be specified
when backing up or restoring router configurations.

Bugs fixed in Version 4.1.6

The following bugs have been fixed in Version 4.1.6:

Static Routes Not Added When Line Protocol Flaps During Port Setup

Version 4.1.6 fixes a bug in the handler functions for static routes under Linux operating
systems.  Previously, if line protocol flapped when a port was activated, which could happen
at boot time with certain protocols, routes added through IP address gateways instead
of device names could fail to be added to the routing table.  Version 4.1.6 maintains an
additional status field allowing the router to add static routes through IP gateways that 
may be unreachable due to line protocol flaps.

Basic BGP Configuration Script Fails When Ethernet0 Has Multiple Addresses

Version 4.1.6 fixes a problem when configuring BGP with GateD using ImageStream's basic
configuration script.  The main GateD configuration file could be cleared accidentally
if Ethernet0 is not configured or is configured with multiple IP addresses.  In Version
4.1.6, the basic configuration script for BGP now checks for configured addresses and uses
only the primary address of Ethernet0 or a reasonable default.

SAND Prevents Addition Of Duplicate VPI/VCI Combinations

Previous 4.1 releases allowed users to configure duplicate VPI/VCI combinations on ATM circuits.
The duplicate would fail, but no error message would be output to the console.  Version 4.1.6
corrects this behavior by outputting a message about the duplicate VPI/VCI and not attempting
to configure the duplicate.

Routes Through Dead Gateway Problem Fixed

Previous 4.1 releases did not allow routes to be added through dead gateways when SAND was loaded.
This behavior caused problems with routes on HDLC and some frame relay interfaces at boot time and
when SAND was reloaded.  While line protocol was down, no routes could be added through an IP
gateway on the device.  Version 4.1.6 corrects this behavior by allowing for routes to be added
through gateways and marked as dead routes.

GateD Menu Prompts For Reload

Version 4.1.6 now prompts users to reload configurations after making changes to GateD configurations
from the router menu.  Previous versions checked the configuration and forced a reload.

Bridging Configuration Error Fixed

Previous versions of Enterprise Linux allowed delete requests for ports that were not part
of the specified bridge.  This behavior also prevented ports from being moved between bridges
without being removed from all bridges first.  Version 4.1.6 now checks bridge group members
prior to attempting to change the membership of a bridge group.