50% of the JNCIS-ENT.

•February 15, 2012 • Comments Off on 50% of the JNCIS-ENT.

I am now 50% through the reading of the JNCIS-ENT-Routing SG. This is a very well written study guide – although very condensed previous knowledge of the subjects is a must. In following my new reading plan (one hour per day) – the SG fits in nice, as a medium pace of reading takes around an hour per chapter/topic. I will be coming back to this PDF again – as the plan is read these at least twice through, and then cover the weak area once again.

Ok – now pastures new. Juniper switching!



The start of the JNCIS-ENT

•February 7, 2012 • Comments Off on The start of the JNCIS-ENT

What I learnt last night – instead of overloading with reading at night and falling asleep with my head in a book. I am taking a different tact for reading – one hour only. I was talking with someone on the Cisco CLN and they were saying that they only read for one hour per night. This allows them not to become overloaded with information, they also find that they can remember more and not have to re-read again later. I thought I would give this a try!

So last night upon starting the reading for the JNCIS-ENT – I sat down and this is one of the things I learnt, which I thought was very cool. It also happen that while doing one of the mock exams on Junipers website for this exam they covered this in a question.

The qualified-next-hop option allows independent preferences for static routes to the same destination.

If this was Cisco this would be called a floating static route. You create a static route to the destination (by default with Juniper the next hop IP address of a static route must be reachable using a direct route) if that next hop become unavailable then the “qualified-next-hop” is used as the next hop.

[edit routing-options]
bigevil@R11# show
static {
route {
qualified-next-hop {
preference 8;

The next hop assumes the default static route preference of 5, while the qualified next hop uses the defined route preference of 8. All traffic using this static route uses the next hop unless it becomes unavailable. If the next hop becomes unavailable, the default static route will then use the next hop.

Another cool feature in the [edit routing-options static] configuration hierarchy, the defaults section can encompass static route options. Any options configured within this section are applied to all static routes on the device.

With this in mind how would the following work?

[edit routing-options]
bigevil@R11# show
static {
defaults {
preference 180;
route {
qualified-next-hop {
preference 8;

The default for preference for static routes has become 180 – therefore has a route preference of 180 instead of 5. The has route preference of 8 which is explicitly set. Thus the next hop is – sweet.


On with the Juniper study/exams

•February 6, 2012 • Comments Off on On with the Juniper study/exams

Ok – enough of a break from study, four days is plenty!

The JNCIS-ENT is the next in the line of fire. I have the study guides from Junipers website, and speaking with people who have passed this exam as long as you have attention for detail this is all you will need reading wise. I covered a great amount of information while studying for the JNCIA (maybe too much) – so i need to cover the ground for this exam.

Layer 2 Switching and VLANs
Spanning Tree
Layer 2 Security
Protocol Independent Routing
Open Shortest Path First (OSPF)
Intermediate System to Intermediate System (IS-IS)
Border Gateway Protocol (BGP)
High Availability

IS-IS is going to be the hardest as i have not read about this since the CCNP BCSI exam back in 2009 (is it that long ago!).


Juniper JNCIA – passed!

•February 2, 2012 • Comments Off on Juniper JNCIA – passed!

I now am proud to have a Juniper GIF on my email signature – I sat the exam today and passed with 80%.
For an entry level exam this is a little tough one and a lot of things are covered, and the fine details are what counts.

Yes it helps i have some years of networking under my belt i did not have learn binary, subnetting, routing and switching – more how to do things the Juniper way and not the Cisco way. As I blogged before – we have Juniper at work so most of the knowledge came from hands on work and asking Ben and Paul (thanks guys) many questions.

Small break now – and on with the study!


Santa came early this year.

•November 25, 2011 • Comments Off on Santa came early this year.

Just got this delivered at work for the new DC.

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Awesome – BE 🙂

Hanging with Todd Lammle.

•November 7, 2011 • Comments Off on Hanging with Todd Lammle.

Saturday the 5th November i had the chance to hang out with one of the great legends in the Cisco networking industry and the author of the best selling CCNA (and others) books – Todd Lammle.

Todd is in the UK for a series of talks and seminars – which kicked off in London. I have known Todd for a few years now, speaking via email and his forum http://www.lammle.com. In many ways i owe him for where i am today as his books, advise and friendship have helped me every step of the way. There is an old sigma/saying that “you should never meet your idols, as they will disappoint you” – in this meeting this was most certainly wrong. Todd is an awesome guy, he is just like he is in his writing style.

I was also able to introduce Todd to my wife and son as they met us at the end of the day- he was most gracious to both her and our little boy.


Juniper COS

•October 23, 2011 • Comments Off on Juniper COS

This was not an easy chapter – even the author(s) said take a break at least four time during the chapter. Even so close to passing the Cisco QOS exam this was still tough going and took me at a week of reading and re-reading. I know i will be reading this section again at some point once the book is done.

A few terms to know –

assured forwarding (AF)
CoS packet forwarding class that provides a group of values you can define and includes four subclasses, AF1, AF2, AF3, and AF4, each with three drop probabilities, low, medium, and high.

behavior aggregate (BA) classifier
Feature that can be used to determine the forwarding treatment for each packet. The behavior aggregate classifier maps a code point to a forwarding class and loss priority. The loss priority is used later in the work flow to select one of the two drop profiles used by random early detection (RED).

best effort (BE)
CoS packet forwarding class that provides no service profile. For the BE forwarding class, loss priority is typically not carried in a code point, and random early detection (RED) drop profiles are more aggressive.

class of service (CoS)
Method of classifying traffic on a packet-by-packet basis, using information in the type-of-service (ToS) byte to assign traffic flows to different service levels.

Differentiated Services (DiffServ)
Services based on RFC 2474, Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers. The DiffServ method of CoS uses the type-of-service (ToS) byte to identify different packet flows on a packet-by-packet basis. DiffServ adds a Class Selector code point (CSCP) and a DiffServ code point (DSCP).

DiffServ code point (DSCP) values
Values for a 6-bit field defined in IP packet headers that can be used to enforce class-of-service (CoS) distinctions.

drop profile
Drop probabilities for different levels of buffer fullness that are used by random early detection (RED) to determine when to drop packets from a given J-series or SRX-series device scheduling queue.

expedited forwarding (EF)
CoS packet forwarding class that provides end-to-end service with low loss, low latency, low jitter, and assured bandwidth.

multifield (MF) classifier
Firewall filter that scans through a variety of packet fields to determine the forwarding class and loss priority for a packet and polices traffic to a specific bandwidth and burst size. Typically, a classifier performs matching operations on the selected fields against a configured value.

network control (NC)
CoS packet forwarding class that is typically high priority because it supports protocol control.

PLP bit
Packet loss priority bit. Used to identify packets that have experienced congestion or are from a transmission that exceeded a service provider’s customer service license agreement. A J-series or SRX-series device can use the PLP bit as part of a congestion control strategy. The bit can be configured on an interface or in a filter.

Feature that limits the amount of traffic passing into or out of an interface. It is an essential component of firewall filters that is designed to thwart denial-of-service (DoS) attacks. A policer applies rate limits on bandwidth and burst size for traffic on a particular J-series device interface.

Applying rate and burst size limits to traffic on an interface.

random early detection (RED)
Gradual drop profile for a given class, used for congestion avoidance. RED attempts to anticipate congestion and reacts by dropping a small percentage of packets from the tail of the queue to prevent congestion.

Guide that the device follows when applying services. A rule consists of a match direction and one or more terms.