NSX-T Forwarding-Table not returning correct route_type

[Venkat Ayyer]

It was recommended that i ask this question in this group so maybe someone can help me here.

Subject: NSX-T Forwarding-Table not returning correct route_type

Does anyone know why the GET for routing type is only returning "route" vs expected route_types as outlined in the guide?

Example:

GET https://<ipaddress>/policy/api/v1/infra/tier-1s/T1-test2/forwarding-table
returns:

"route_entries": [

{

"route_type": "route",

"network": "10.60.1.9/24",

"admin_distance": 0,

"next_hop": "",

......

"lr_component_type": "SERVICE_ROUTER_TIER1"

},

and per the documentation should be something like:
 { "next_hop": "169.254.0.2",

 "route_type": "c ",

"admin_distance": 0,

"network": "169.254.0.0/28" }

[Venkat Ayyer]

Does anyone have any thoughts on this one or seeing the same thing from the APIs?

[Venkat Ayyer]

Anyone?

[Bogdan28]

Possible Causes:

1. NSX-T Version Mismatch:
   Ensure that the NSX-T version you are using aligns with the documentation. Some features or attributes might be available only in certain versions.

2. Tier-1 Router Configuration:
   The response may vary depending on the configuration of the Tier-1 router. If you are using static routes, the route_type might return as "route". For dynamic routes (OSPF, BGP), the route_type should reflect the actual protocol.

3. Dynamic Routing Protocols Disabled:
   If dynamic routing protocols (like OSPF or BGP) are not enabled, all routes might return as "route". Ensure that these protocols are active if you expect to see "o" (OSPF) or "b" (BGP) types.

4. NSX-T API Endpoint:
   The /forwarding-table API endpoint might return only basic information. To gather more detailed route types, consider using the /routes endpoint, which might provide additional context for each route entry.

5. Unexpected Route Types:
   If the route_type is unexpectedly returning "route", this may be due to the current router's configuration or an API limitation.

To investigate further, you can use the following Python script to query the NSX-T API and analyze the results

import requests
import json

# Configuration
NSX_MANAGER = "https://<nsx-manager-ip>"
USERNAME = "<your-username>"
PASSWORD = "<your-password>"
TIER1_ROUTER = "T1-test2"  # Replace with your Tier-1 router name
API_ENDPOINT = f"{NSX_MANAGER}/policy/api/v1/infra/tier-1s/{TIER1_ROUTER}/forwarding-table"

# Disable SSL warnings
import urllib3
urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)

def fetch_forwarding_table():
    try:
        # API Call
        response = requests.get(
            API_ENDPOINT,
            auth=(USERNAME, PASSWORD),
            verify=False  # Use verify=True with valid certificates
        )
        
        if response.status_code == 200:
            data = response.json()
            analyze_response(data)
        else:
            print(f"Failed to fetch data. Status Code: {response.status_code}")
            print("Response:", response.text)
    except Exception as e:
        print(f"Error during API call: {e}")

def analyze_response(data):
    if "route_entries" not in data:
        print("No route_entries found in the response.")
        return
    
    route_entries = data["route_entries"]
    print(f"Found {len(route_entries)} route entries.\n")

    for idx, entry in enumerate(route_entries, start=1):
        print(f"Route Entry {idx}:")
        print(f"  Network: {entry.get('network')}")
        print(f"  Route Type: {entry.get('route_type')}")
        print(f"  Admin Distance: {entry.get('admin_distance')}")
        print(f"  Next Hop: {entry.get('next_hop', 'N/A')}")
        print(f"  Component Type: {entry.get('lr_component_type', 'N/A')}")
        print("-" * 40)

    # Check for unexpected route types
    unexpected_route_types = [
        entry for entry in route_entries if entry.get("route_type") == "route"
    ]
    if unexpected_route_types:
        print("\nRoutes with 'route_type' as 'route' found:")
        for entry in unexpected_route_types:
            print(f"  Network: {entry.get('network')}, Route Type: {entry.get('route_type')}")
    else:
        print("\nNo unexpected route types detected.")

if __name__ == "__main__":
    fetch_forwarding_table()

Replace the placeholders (<nsx-manager-ip>, <your-username>, <your-password>) with your actual NSX-T Manager details. Run the script using Python. It will query the NSX-T API and print the route entries.