Inspect matching rule, applied attributes, selected route and resolved FIB next hop. This check would diagnose Route-policy next-hop and preference application, but would not first isolate the described BGP route-reflector client scoping. Begin with: Inspect peer reflect-client settings, received and advertised routes and RR topology.

Inspect EVPN NLRI route types, MAC/IP attributes, VNI bindings and desired prefix routes. This check would diagnose EVPN Type-2 MAC/IP route interpretation, but would not first isolate the described BGP route-reflector client scoping. Begin with: Inspect peer reflect-client settings, received and advertised routes and RR topology.

Inspect configured peer AS, received OPEN messages and BGP neighbor reset reasons. This check would diagnose BGP peer autonomous-system mismatch, but would not first isolate the described BGP route-reflector client scoping. Begin with: Inspect peer reflect-client settings, received and advertised routes and RR topology.

Permit the specifically authorized BGP TCP session over the intended neighbor path and keep unrelated management traffic restricted. This is a legitimate response to the different issue of BGP TCP reachability and port, but it does not correct the specific MP-BGP address-family activation condition reported. The relevant technical distinction is: MP-BGP carries address-family-specific routes only when corresponding capabilities and peers are configured.

Validate supported CSS inter-chassis links, roles, redundancy and a controlled master-failover test. This is a legitimate response to the different issue of CSS chassis clustering and failover, but it does not correct the specific MP-BGP address-family activation condition reported. The relevant technical distinction is: MP-BGP carries address-family-specific routes only when corresponding capabilities and peers are configured.

Use a supported consistent IS-IS metric style and cost plan across affected peers. This is a legitimate response to the different issue of IS-IS metric-style consistency, but it does not correct the specific MP-BGP address-family activation condition reported. The relevant technical distinction is: MP-BGP carries address-family-specific routes only when corresponding capabilities and peers are configured.

The intended security associations establish and permitted tunnel traffic traverses encrypted. That observation would support a separate case of IPsec peer proposal compatibility, not verification of the reported MP-BGP address-family activation. The relevant observable outcome here is: The required EVPN NLRI appears in the appropriate address-family tables without affecting IPv4 policy.

The Level-1 router chooses an intended attached exit and reaches approved remote prefixes. That observation would support a separate case of IS-IS L1 default to nearest attached L1L2, not verification of the reported MP-BGP address-family activation. The relevant observable outcome here is: The required EVPN NLRI appears in the appropriate address-family tables without affecting IPv4 policy.

Internal BGP route decisions prefer the intended provider for matched prefixes and fail over if unavailable. That observation would support a separate case of BGP local preference internal egress, not verification of the reported MP-BGP address-family activation. The relevant observable outcome here is: The required EVPN NLRI appears in the appropriate address-family tables without affecting IPv4 policy.

WLAN VLAN pools can distribute large client populations across multiple user VLANs when correctly integrated with DHCP. This explains WLAN VLAN pool address distribution, but not why the issue in this scenario occurs. The specific mechanism is: MP-BGP carries address-family-specific routes only when corresponding capabilities and peers are configured.

BGP ORIGIN ranks IGP ahead of EGP and Incomplete after preceding path-selection rules. This explains BGP origin attribute tie break, but not why the issue in this scenario occurs. The specific mechanism is: MP-BGP carries address-family-specific routes only when corresponding capabilities and peers are configured.

BGP NO_EXPORT community constrains external AS propagation when carried and honored. This explains BGP route policy community NO_EXPORT, but not why the issue in this scenario occurs. The specific mechanism is: MP-BGP carries address-family-specific routes only when corresponding capabilities and peers are configured.

A WAN interface reporting link-up does not prove acceptable end-to-end application performance. This consequence is associated more directly with SD-WAN underlay and application steering. For the stated conditions the immediate exposure is: A BGP Established session alone does not prove EVPN address family exchange works.

Changing inbound MED may not correct the enterprise's outbound egress preference. This consequence is associated more directly with BGP local preference internal egress. For the stated conditions the immediate exposure is: A BGP Established session alone does not prove EVPN address family exchange works.

Uncontrolled reimport can create persistent false reachability after a primary path fails. This consequence is associated more directly with Redistribution route tag loop avoidance. For the stated conditions the immediate exposure is: A BGP Established session alone does not prove EVPN address family exchange works.

Check BGP NEXT_HOP, recursive route resolution and underlay reachability on the receiver. This check would diagnose iBGP next-hop reachability, but would not first isolate the described MP-BGP address-family activation. Begin with: Inspect AFI/SAFI negotiation, peer AF activation and received EVPN routes.

Inspect rejected UPDATE attributes, local AS number and AS_PATH on each advertised prefix. This check would diagnose BGP AS_PATH loop detection, but would not first isolate the described MP-BGP address-family activation. Begin with: Inspect AFI/SAFI negotiation, peer AF activation and received EVPN routes.

Compare received candidate paths, LOCAL_PREF values, route policy and installed best path. This check would diagnose BGP local preference internal egress, but would not first isolate the described MP-BGP address-family activation. Begin with: Inspect AFI/SAFI negotiation, peer AF activation and received EVPN routes.

Evaluate eligible candidate paths and select the shorter AS_PATH when earlier BGP preference criteria do not decide. This is a legitimate response to the different issue of BGP AS_PATH length egress choice, but it does not correct the specific MP-BGP address-family activation condition reported. The relevant technical distinction is: MP-BGP carries address-family-specific routes only when corresponding capabilities and peers are configured.

Apply supported next-hop handling such as next-hop-local where appropriate and provide underlay reachability. This is a legitimate response to the different issue of iBGP next-hop reachability, but it does not correct the specific MP-BGP address-family activation condition reported. The relevant technical distinction is: MP-BGP carries address-family-specific routes only when corresponding capabilities and peers are configured.

Correct the Huawei ACL wildcard address scope and rule sequence using explicit positive and negative tests. This is a legitimate response to the different issue of ACL wildcard and rule sequence, but it does not correct the specific MP-BGP address-family activation condition reported. The relevant technical distinction is: MP-BGP carries address-family-specific routes only when corresponding capabilities and peers are configured.

Reflected routes reach intended clients without repeated originator or cluster loops. That observation would support a separate case of BGP route reflector cluster loop prevention, not verification of the reported MP-BGP address-family activation. The relevant observable outcome here is: The required EVPN NLRI appears in the appropriate address-family tables without affecting IPv4 policy.

The restricted destination is denied and authorized comparison traffic succeeds in a controlled test. That observation would support a separate case of ACL packet filter rule order and direction, not verification of the reported MP-BGP address-family activation. The relevant observable outcome here is: The required EVPN NLRI appears in the appropriate address-family tables without affecting IPv4 policy.

Clients obtain a valid address lease, gateway and DNS options from the authorized remote DHCP server. That observation would support a separate case of DHCP relay to remote server, not verification of the reported MP-BGP address-family activation. The relevant observable outcome here is: The required EVPN NLRI appears in the appropriate address-family tables without affecting IPv4 policy.

BGP OPEN negotiation validates the expected peer AS and session parameters. This explains BGP peer autonomous-system mismatch, but not why the issue in this scenario occurs. The specific mechanism is: MP-BGP carries address-family-specific routes only when corresponding capabilities and peers are configured.

BGP exchanges routing control messages over an established TCP transport connection. This explains BGP TCP reachability and port, but not why the issue in this scenario occurs. The specific mechanism is: MP-BGP carries address-family-specific routes only when corresponding capabilities and peers are configured.

Prefix lists match both an address prefix and a configurable prefix-length range. This explains Prefix-list network and mask matching, but not why the issue in this scenario occurs. The specific mechanism is: MP-BGP carries address-family-specific routes only when corresponding capabilities and peers are configured.

Misconfigured reflector clusters can suppress valid routes or permit duplicate advertisements. This consequence is associated more directly with BGP route reflector cluster loop prevention. For the stated conditions the immediate exposure is: A BGP Established session alone does not prove EVPN address family exchange works.

Unrestricted leaking can expand LSDB size and introduce unintended route preference. This consequence is associated more directly with IS-IS selective L2-to-L1 route leaking. For the stated conditions the immediate exposure is: A BGP Established session alone does not prove EVPN address family exchange works.

Using arbitrary AS numbers to make a session open can break routing policy and loop prevention. This consequence is associated more directly with BGP peer autonomous-system mismatch. For the stated conditions the immediate exposure is: A BGP Established session alone does not prove EVPN address family exchange works.

Inspect tracked uplinks, priority changes, VRRP master transition and end-to-end reachability. This check would diagnose VRRP uplink tracking and priority decrement, but would not first isolate the described MP-BGP address-family activation. Begin with: Inspect AFI/SAFI negotiation, peer AF activation and received EVPN routes.

Inspect configured peer AS, received OPEN messages and BGP neighbor reset reasons. This check would diagnose BGP peer autonomous-system mismatch, but would not first isolate the described MP-BGP address-family activation. Begin with: Inspect AFI/SAFI negotiation, peer AF activation and received EVPN routes.

Inspect import policy, level-specific LSP advertisements and the Level-1 route table. This check would diagnose IS-IS selective L2-to-L1 route leaking, but would not first isolate the described MP-BGP address-family activation. Begin with: Inspect AFI/SAFI negotiation, peer AF activation and received EVPN routes.