Initial triage: cisco_xr_ios_vpnv4 lab validation failures (never tested before)

[dhalperi]

Problem

The cisco_xr_ios_vpnv4 lab exhibits multiple validation failures when comparing Batfish route predictions against actual device operational data in an MPLS VPN environment with IOS-XR provider edge devices and IOS customer edge devices.

Technical Details

This lab implements MPLS VPN with LDP for label exchange and MP-BGP with VPNv4 unicast address family. The validation failures indicate discrepancies between Batfish modeling and actual device behavior for both main RIB routes and BGP RIB routes across multiple devices.

Observed In

cisco_xr_ios_vpnv4

Symptoms

• Main RIB route validation failures on 8 devices (CE2, CE3, CE4, PE1, PE2, PE3, RR1, RR2)
• BGP RIB route validation failures on 6 devices (CE2, CE3, CE4, PE1, PE2, PE3)
• Route matching issues between device operational data and Batfish predictions
• Specific examples include missing BGP routes like 11.1.1.0/24 on CE2 and route discrepancies on PE devices

Configuration Patterns

• MPLS VPN topology with 5 IOS-XR provider devices (PE1, PE2, PE3, RR1, RR2)
• 4 IOS customer edge devices (CE1, CE2, CE3, CE4)
• MP-BGP VPNv4 address family configuration
• LDP-based MPLS label distribution
• OSPF as IGP in provider core

Next Steps

Investigation needed into Batfish MPLS VPN modeling, particularly:

• VPNv4 route processing and RD/RT handling
• Route redistribution between BGP and IGP in VRF contexts
• IOS-XR specific BGP behavior in MPLS VPN scenarios
• Cross-vendor route exchange validation (IOS-XR PE to IOS CE)