Templating for network engineers in SaltStack.

Posted on June 8, 2019

Templating in SaltStack is an absolute joy. It makes the generation of text-based configurations for networking devices very easy. This write up is to give you some tips and insights that I could have used when I started templating myself. After walking you through an easy way to render templates... [Read More]
Tags: automation saltstack

Getting your facts straight.

Posted on May 10, 2019

The Salt grains interface is a very powerful tool. The interface presents Salt with grains of information about the system that is being managed. One of the things you can use grains for is to make your templating more effective. As a network engineer, I mostly work with proxy-minions. And... [Read More]
Tags: automation saltstack

Troubleshooting packet loss with firewall filters

Posted on July 3, 2016

Packet loss can be caused by all sorts of reasons. Could be faulty hardware, a software issue on a device, a congested link or some policers and shapers that are working against you. In order to fix packet loss in a network, you first have pinpoint where the packets are... [Read More]
Tags: juniper

Introducing packet loss with RED

Posted on April 5, 2016

Recently, a customer had several issues going on at the same time. The customer had an MPLS L3VPN with a default route towards a central firewall in the datacenter. Behind this firewall, there was some rackspace and a cloud environment. A lot of components were involved and after solving the... [Read More]
Tags: juniper

Q-in-Q on EX, QFX or VCF

Posted on January 14, 2016

Configuring Q-in-Q, or dot1q tunneling can lead to some confusion. I’ve seen confusion due to changes in the new enhanced Layer 2 CLI configuration and because of a mismatch in Ethertype. This is a short article on how QinQ can be configured on an EX, QFX or VCF. I’ll configure... [Read More]
Tags: juniper

Huawei basic layer 3 MPLS VPN

Posted on October 11, 2015

Normally, I use Huawei for all sorts of CPE stuff. But this time, instead of connecting a Huawei CPE to an MPLS VPN, I thought I’d use Huawei to create the Layer 3 MPLS VPN itself. Using eNSP, the free and open Enterprise Simulation Platform, I created the following scenario:... [Read More]
Tags: huawei

Policy based LSP mapping with Junos OS

Posted on October 2, 2015

LSPs can be configured with a whole variety of characteristics. You can police traffic that is send onto an LSP, steer the LSP through certain location in the network and much more. When you create several LSPs towards the same destination router, prefixes using that router as a next-hop are... [Read More]
Tags: juniper

Basic BGP import filtering example on Junos OS

Posted on September 28, 2015

What your BGP peers decide to advertise is out of your control. What you accept is not. This is a short article on basic route-filtering using Junos. The focus here is on a BGP import policy for public peering. Let’s start of by rejecting all 0.0.0.0/x routes: [Read More]
Tags: juniper

Junos and all things syslog

Posted on September 4, 2015

This article is about Junos and all things syslog. I'll go over several examples showing you what you can configure under the [ system syslog ] stanza. Parts of the examples I use here are based on what I think can benefit a device running Junos OS. I'll cover logging... [Read More]
Tags: juniper

Juniper OSPFv3 IPsec authentication

Posted on August 26, 2015

Though the OSPFv3 protocol does not offer a built-in authentication method, IPsec can be used to secure protocol exchanges between devices running OSPFv3. To authenticate OSPFv3 on a Juniper device, you first start out with the configuration of a Security Association (SA). The SA describes how the devices will communicate... [Read More]
Tags: juniper

Juniper MX and RSVP refresh reduction

Posted on August 12, 2015

The past few weeks I have been working on the replacement of several core nodes. After finally installing the last MX, I wanted revise several configurations that were applied. One of the configurations that I revised was the configuration used in the RSVP stanza. I ‘optimized’ it by implementing RSVP... [Read More]
Tags: juniper mpls rsvp

Setting up your own vSRX lab

Posted on August 1, 2015

Recently, I’ve been having some fun with the vSRX. I wanted to share the lab I created so others can see how easy it is to get things going with the vSRX. The vSRX doesn’t require a lot of resources and it is a really nice way to get acquainted... [Read More]
Tags: juniper

IPFIX configuration example

Posted on July 23, 2015

Turning on IPFIX (IP Flow Information Export) on Juniper MX is a good idea if you want to know what’s going on. Not only can it provide you with a tremendous insight into the traffic traversing your network, you can also use the information provided by IPFIX to automatically divert... [Read More]
Tags: juniper

Juniper Virtual Chassis Fabric AE interface

Posted on June 29, 2015

Connecting other parts of the network to the VCF in a redundant way using Link Aggregation Groups (LAG) is very easy. A LAG can combine several Ethernet interfaces into a single logical link called an Aggregate Ethernet (AE) interface. When you are running a VCF, you’d best spread a LAG... [Read More]
Tags: juniper qfx vcf

Juniper Virtual Chassis Fabric

Posted on June 28, 2015

Having to deal with a network edge that organically grew as time passed, evolving into an ever more complicated constellation of switches, is frustrating. Looming in the back of my mind were choices made in a past I had no part of. Those choices strained growth and frustrated my attempt... [Read More]
Tags: juniper qfx vcf