- Written by Nandan Saha
- Posted on August 24, 2020
- Updated on May 22, 2024
- 10968 Views
The BGP-LS extension allows IGPs (OSPF/IS-IS) link state database information to be injected into BGP. This is typically used in deployments where some external component, (like a controller or Path Computation Engine) can do centralized path computations by learning the entire IGP topology through BGP-LS. The controller can then communicate the computed paths based on the BGP-LS updates to the head end device in the network. The mechanism used by the controller to communicate the computed TE paths is outside the scope of this document. Using BGP-LS instead of an IGP peering with the controller to distribute IGP link state information has the following advantages.
- Written by Kundan Sen
- Posted on August 23, 2019
- Updated on September 5, 2019
- 6511 Views
EOS 4.22.1F adds support for disabling the IS IS authentication check for received IS IS PDUs. By enabling this
- Written by Pauric Ward
- Posted on March 13, 2024
- Updated on April 29, 2024
- 2481 Views
Administrative Groups (AG) provide a way to associate certain attributes or policies with links, enabling network administrators to control the routing decisions based on specific criteria. Extended Administrative Groups (EAG) are an extension of AG which allow a larger range of admin groups to be utilized for various Traffic Engineering (TE) purposes within a network.
- Written by Arpit Bansal
- Posted on December 21, 2020
- Updated on January 17, 2022
- 7864 Views
IGP shortcuts enable traffic to get forwarded along traffic engineered paths computed by RSVP using a modified SPF
- Written by Tanushree Bansal
- Posted on June 11, 2019
- Updated on June 20, 2019
- 6617 Views
This feature implements RFC6119, which allows the extension of IS IS protocol to carry IPv6 Traffic Engineering
- Written by Subham Burnwal
- Posted on June 28, 2024
- Updated on June 28, 2024
- 1037 Views
EOS IS-IS implementation advertises interface-address TLVs for both passive and non-passive interfaces. IS-IS “advertise interface-address passive-only” feature is used to control the advertisement of interface address TLVs in LSP Advertisement. Once this feature is enabled on the device, IS-IS advertises interface address TLVs i,e. IP Interface Address TLV #132 and IPv6 Interface Address TLV #232 only for passive interfaces in the LSP Advertisement and stops advertising these TLVs for active or non-passive interfaces.
- Written by Tony Li
- Posted on December 22, 2020
- Updated on December 22, 2020
- 7341 Views
IS IS area proxy allows the creation of more scalable networks. IS IS already has hierarchical mechanisms for
- Written by Arnab Das
- Posted on January 22, 2019
- Updated on September 30, 2024
- 6264 Views
The ‘clear isis instance’ command can be used to reset the ISIS instance that is running. All ISIS instance and interface states will be cleared and re-initialized from the configuration so that ISIS rediscovers neighbors and reconverges the different instances in the ISIS routing tables.
- Written by Zetang Lei
- Posted on July 2, 2024
- Updated on July 3, 2024
- 1040 Views
This feature introduces a way for IS-IS to advertise its IP reachability and SID for loopback interfaces only when routes matching an RCF function are present. One example use-case is to use IS-IS Segment Routing to attract traffic to a router only when routes towards the ultimate destination are present.
- Written by Nitin Sao
- Posted on November 9, 2021
- Updated on November 9, 2021
- 6270 Views
This feature allows configuration of the IS IS CSNP generation interval. The default CSNP interval is 10
- Written by Sarah Chen
- Posted on January 12, 2022
- Updated on October 30, 2023
- 9644 Views
IS-IS flexible algorithm (FlexAlgo) provides a lightweight, simplified mechanism for performing basic traffic engineering functions within a single IS-IS area. FlexAlgo requires the cooperation of all nodes within the IS-IS area but does not require an external controller. Paths are computed by each node within the area, resulting in an MPLS switched forwarding path to nodes that are advertising a node Segment Identifier (SID) for the algorithm. The results of the path computation are placed in the colored tunnel RIB or system tunnel RIB, which simplifies route resolution.
- Written by Chris Roche
- Posted on April 20, 2020
- Updated on April 26, 2021
- 6695 Views
The IS IS maximum LSP size feature provides the ability to configure the maximum LSP size that the IS IS protocol will
- Written by Arpit Bansal
- Posted on August 18, 2020
- Updated on August 18, 2020
- 6820 Views
Level 1 2 routers set attached bit in their Level 1 LSPs to indicate their reachability to the rest of the network. A
- Written by Pintu Kumar
- Posted on April 23, 2018
- Updated on February 24, 2023
- 7559 Views
Traffic Engineering (TE) provides a mechanism to network administrators to control the path that a data packet takes, bypassing the standard routing model which uses routes along the shortest path. Traffic engineered paths are generally computed on the head-end routers of the topology based on various constraints (e.g. minimum bandwidth, affinity) configured for those paths and attributes (e.g available bandwidth, color) received from devices in the network topology.
- Written by Manoj Agiwal
- Posted on September 30, 2019
- Updated on September 30, 2019
- 6497 Views
This feature allows a user to configure multiple static adjacency SIDs for an IS IS adjacency. This feature is an
- Written by Girish Dasari
- Posted on May 11, 2021
- Updated on May 11, 2021
- 6555 Views
IS IS adjacency is not formed between devices with different address families configured. For example, a router
- Written by Saurav Arora
- Posted on January 7, 2022
- Updated on January 7, 2022
- 6639 Views
Traffic steering enables traffic for a specified set of prefixes to get forwarded along traffic engineered paths
- Written by Girish Dasari
- Posted on September 11, 2024
- Updated on September 11, 2024
- 325 Views
IS-IS SR Stateful Switchover (SSO) support allows for a switchover from an active supervisor to a standby supervisor where MPLS traffic remains undisrupted during switchover. This involves reconciliation of all Segment Routing related information in the network using IS-IS Graceful Restart procedures. And also installing the same in forwarding hardware in a manner that does not disrupt the ongoing traffic.
- Written by Kundan Sen
- Posted on August 18, 2022
- Updated on August 22, 2022
- 5338 Views
This feature adds support for configuring multiple area addresses in an IS-IS instance.
- Written by Sandeep Kopuri
- Posted on October 7, 2019
- Updated on May 17, 2024
- 10486 Views
Topology Independent Fast Reroute, or TI-LFA, uses IS-IS SR to build loop-free alternate paths along the post-convergence path. These loop-free alternates provide fast convergence.
- Written by Kundan Sen
- Posted on November 12, 2019
- Updated on November 12, 2019
- 5992 Views
EOS 4.23.0F adds support for redistributing DHCPv6 routes in IS IS when using the multi agent routing protocol mode.