Tech Library
OSPF Overload
1. Intro OSPF Overload: configure the local routing device so that it appears to be overloaded. You might do this when you want the routing device to participate in OSPF routing, but do not want it to be used for transit traffic. There is no overload bit, like we have in ISIS Overload. Instead, OSPF […]
OSPF Summarization
1. Intro In the previous post we applied OSPF basic config on our test network. We had 2 areas; one of them is a Totally NSSA area. In this post will do some OSPF route summarization on the same topology, continuing from where we left off. For easy reference find the OSPF database as it […]
OSPF Basic config
1. Intro In this post we will apply OSPF basic config on our test network. We have 2 areas; one of them will be a Totally NSSA area. In the next post will do some OSPF route summarization on the same topology. 2. OSPF Basic config We will configure a topology with multiple areas: The […]
ISIS Cheat Sheet
ISIS – Interior Gateway Protocol (IGP) Type: Link State Algorithm: Dijkstra Metric: 10 for any interface0 for Loopback interface Metric Type: Narrow and Wide by default. But, ISIS silently limits metric to 63.In modern ISIS deployments we should enable wide-metric-only. Preference (AD): 15 / 18 (L1/L2 Internal)160 / 165 (L1/L2 External) PDU Types IIH IS-IS […]
Login Classes
Junos Login Classes define user access privileges, permissions for using CLI commands and statements. 1. Login Classes Junos OS includes predefined login classes that can’t be modified: Login Class Permission Flag Set super-user all operator clear, network, reset, trace, and view read-only view unauthorized none Additionally, we define any number of login classes. However, we can […]
System Scripts
Junos automation consists of a suite of tools used to automate operational and configuration tasks on network devices running Junos. In this post we will configure different system scripts on the router. 1. Basic system script configuration First, we need to copy the scripts to the router: The script files must be copied to a […]
Syslog
We can configure Junos syslog at the [edit system syslog] hierarchy level, and we can direct the system syslog messages to the following destinations: (console | file filename | host destination | user username): For all destinations we must mention the Facility and Severity: The Junos OS system logging facilities that you can specify in […]
ISIS metric – 3rd trap, the differences between IPv4 and IPv6
1. Intro In this part we will focus on the ISIS IPv6 metric, more specifically, the differences between IPv4 and IPv6. But before that, let’s remind ourselves that this post is part of a 3 part series about the impact of ISIS Narrow and Wide metrics: 2. The test topology The topology is the same, […]
ISIS Metric – 2nd trap, the unexpected impact of wide-metrics-only
1. Intro In this part we will focus on the use unexpected impact of the wide-metrics-only knob. But before that, let’s remind ourselves that this post is part of a 3 part series about the impact of ISIS Narrow and Wide metrics: 2. The test topology We will update our test topology to demonstrate the […]