October 2012
Intermediate to advanced
902 pages
28h 9m
English
Content preview from Juniper MX SeriesBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
In-Service Software Upgrades
The Junos ISSU feature allows for a virtually hitless upgrade from one supported ISSU release to another. As mentioned previously, the foundation of ISSU is NSR, as during the ISSU process a GRES switchover occurs as the original standby becomes master to allow the old master (new backup) to be upgraded. Like GRES and NSR, ISSU can only be used on systems with redundant REs.
What is a supported ISSU release? In most cases, you are limited to no more than three major releases, and in theory any extended End-of-Life (EEOL) release to a current release should work. This section details current ISSU operation and restrictions for Trio-based MX routers running Junos 11.4.
ISSU Operation
At a high level, ISSU operation is pretty straightforward. Things
begin when you include the in-service-upgrade switch rather than add when using the request system software command. The current
master then pushes the new software bundle to the BU RE, where it’s
installed. After the BU RE reboots with the new software, the current
master upgrades the PFE components in a sequential manner, which induces
a brief dataplane outage known as a dark window. Next, a GRES event is
triggered to make the old BU the new master, at which point the new BU
(old master) begins installing the new software. When all goes to plan,
you are left with both REs on the new software, now with RE1 as the
master, all with no control plane hit and only a brief period of
disruption to the data plane.
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.