Simplified OSPF module for ns-3

This project is an external module for the ns-3 network simulator, implementing basic functionality of the Open Shortest Path First Version 2 (OSPFv2) routing protocol as defined in RFC 2328. This module is targetted for ns-3 version 3.35.

License

This software is licensed under the terms of the GNU General Public License v2.0 only (GPL-2.0-only). See the LICENSE file for more details.

Table of Contents:

1. Overview
2. Instruction
3. Continuous Integration
4. Citation
5. Reporting Issues

Overview

What's currently implemented

• Basic OSPF functionality for point-to-point routers and multi-access networks
• Data synchronization and flooding procedures
• Area Proxy implementation (RFC 9666) for OSPF
• LSA separation between router reachability and prefix advertisement (Similar to OSPFv3)
• Prefix Injection
• Import/Export functionality of the OSPF state (LSA, neighbor, leadership)

Major Simplifications

• Link State Updates subject to flooding contain only one Link State Advertisement (LSA) each.
  • Link State Updates serving as implicit acknowledgments to Link State Requests may contain multiple LSAs, up to the specified MTU.
• Link State Updates received within a short time window are not aggregated.
• Authentication is not implemented.
• Inter-AS routing is not implemented.

Current Limitations

• Does not implement Designated Router (DR) and Backup Designated Router (BDR).
• Network devices added after the OSPF application starts are not dynamically registered unless AutoSyncInterfaces is enabled.

Continuous Integration

This repository includes a GitHub Actions workflow that builds ns-3 and runs all OSPF test suites (ospf-*):

• Workflow: .github/workflows/main.yml

To run the same OSPF test suites locally from an ns-3 checkout (after placing this repository at ns-3-dev/contrib/ospf):

./waf configure --enable-tests --enable-asserts -d debug
./waf

./test.py --nowaf --list > test-suites.txt
ospf_suites=$(awk 'NR>2 {print $2}' test-suites.txt | grep -E '^ospf-' | sort -u)
suite_args=""
for s in $ospf_suites; do suite_args="$suite_args -s $s"; done

# shellcheck disable=SC2086
./test.py --nowaf $suite_args -v

Citation

If you use this software in research, please cite the Zenodo record:

Theeranantachai, S. (2026). ns3-ospf (v1.0.0) [Computer software]. Zenodo. https://doi.org/10.5281/zenodo.18843774

BibTeX:

@software{theeranantachai_2026_ns3_ospf,
   author    = {Theeranantachai, Sirapop},
   title     = {ns3-ospf},
   version   = {v1.0.0},
   publisher = {Zenodo},
   year      = {2026},
   doi       = {10.5281/zenodo.18843774},
   url       = {https://doi.org/10.5281/zenodo.18843774}
}

Instruction

Installing ns-3

Ensure you have ns-3 version 3.35 installed. You can follow this installation guide to set up prerequisites.

Clone and checkout ns-3 version 3.35:

git clone https://gitlab.com/nsnam/ns-3-dev.git
cd ns-3-dev
git checkout -b ns-3.35-branch ns-3.35

Adding the OSPF Module

Place this repository in ns-3's /contrib directory as /contrib/ospf:

cd contrib
git clone git@github.com:markverick/ns3-ospf.git ospf

Running Examples

Run an example with ns-3 logging:

NS_LOG="OspfApp" ./waf --run=ospf-metric

Resulting PCAP files and routing tables can be found in /results/<example>/.

For debugging with gdb:

NS_LOG="OspfInterface:OspfNeighbor" ./waf --run=ospf-metric --gdb

Reporting Issues

If you would like to report an issue, you can open a new issue in the GitLab issue tracker. Before creating a new issue, please check if the problem that you are facing was already reported and contribute to the discussion, if necessary.