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 […]
ISIS Metric – 1st trap of Narrow and Wide metrics
1. Intro The ISIS Metric topic will have 3 parts: 2. The ISIS metric defaults A quick review of the ISIS metric defaults: 3. The unexpected impact of using both Narrow and Wide by default As already mentioned, Junos uses a combination of both Narrow and Wide metrics. But why use both? Well, the advantage […]
L2VPN – Overview and Basic Configuration
LDP (Martini) and BGP (Kompella) are two L2VPN technologies are supported in Junos. Both L2VPN technologies are used for connectivity of customer attachment circuits across the provider MPLS network. A L2VPN is a point-to-point connection between two PE routers. This type of VPN emulates transparent L2 services for the customers. Normally the L2 attachment circuits […]
RSVP – Basic Config
1. Intro We will use the following test topology for RSVP: For RSVP basic configuration we need to perform the following: 2. RSVP Basic Configuration We we will demonstrate RSVP basic config on R1 router (all other routers already configured): External Resouces:
BGP Attributes
BGP attributes are grouped in four main classes: These attributes are very important to master for the JNCIE-SP lab exam.