AWS sends IKE negotiation to the configured customer endpoint, so an unreachable or incorrect outside address prevents establishment; this belongs to accurate public termination identity for a hybrid VPN, while the problem is perimeter firewall support for both VPN tunnels.

Tunnel-state metrics expose endpoint availability; route-specific checks distinguish an encrypted tunnel from viable routed destinations; this changes proactive visibility into hybrid tunnel outages, not the necessary perimeter firewall support for both VPN tunnels.

In the propagation of corporate networks using VPN BGP workflow, an established IPsec security association does not by itself exchange dynamic networks; BGP must originate acceptable prefixes across the tunnel; the current case needs perimeter firewall support for both VPN tunnels.

A customer gateway identifies each peer router or endpoint; separate connections prevent all tunnels from depending on a single customer device; that addresses device-diverse hybrid IPsec termination, rather than accurate public termination identity for a hybrid VPN.

Phase-one negotiation requires both peers to agree on IKE and cryptographic parameters before protected traffic can traverse the tunnel; this belongs to compatible IKE negotiation parameters, while the problem is accurate public termination identity for a hybrid VPN.

VPN resilience depends on reachability of both independently addressed AWS tunnel endpoints, not merely having two configured AWS tunnels; this changes perimeter firewall support for both VPN tunnels, not the necessary accurate public termination identity for a hybrid VPN.

Resolver forwarding rules select DNS namespaces and outbound DNS targets, not IP forwarding entries for a Transit Gateway route table. CIDR destination changes need a routing control.

Propagation learns attachment-reachable routes; it does not define an arbitrary compliance-approved collection of destination prefixes toward one chosen inspection attachment.

A 0.0.0.0/0 route directs all otherwise unmatched IPv4 destinations to inspection, changing forwarding beyond the specifically approved compliance CIDRs.

TGW attachment acceptance controls whether shared consumers become connected before the owner explicitly authorizes them; that addresses manual authorization of cross-account attachments, rather than materialized cross-account TGW attachment.

TGW ingress is evaluated against the associated TGW route table; a VPC route alone cannot resolve the second-hop destination; this belongs to TGW route-table entry for an attached destination, while the problem is materialized cross-account TGW attachment.

In the cross-account separation of network and workload control workflow, VPC sharing separates network administration from participant workload management without duplicating the underlying subnets; the current case needs materialized cross-account TGW attachment.

TGW ingress is evaluated against the associated TGW route table; a VPC route alone cannot resolve the second-hop destination; that addresses TGW route-table entry for an attached destination, rather than association-dependent TGW lookup.

Resource sharing grants use of the TGW but does not itself connect workload VPCs to the network dataplane; this belongs to materialized cross-account TGW attachment, while the problem is association-dependent TGW lookup.

AWS transit forwarding is bidirectional only when each direction has an effective path; security-group statefulness cannot fabricate missing reverse routes; this changes symmetrical forward and return connectivity through transit, not the necessary association-dependent TGW lookup.

TGW ingress is evaluated against the associated TGW route table; a VPC route alone cannot resolve the second-hop destination; that addresses TGW route-table entry for an attached destination, rather than symmetrical forward and return connectivity through transit.

Resource sharing grants use of the TGW but does not itself connect workload VPCs to the network dataplane; this belongs to materialized cross-account TGW attachment, while the problem is symmetrical forward and return connectivity through transit.

In the deliberate drop action within transit routing workflow, A TGW blackhole route discards packets that match its destination rather than forwarding them to any attachment; the current case needs symmetrical forward and return connectivity through transit.

This produces association-dependent TGW lookup: The TGW examines only the ingress attachment's associated table when forwarding; propagation into an unrelated table changes no dev path; the stem instead tests symmetrical forward and return connectivity through transit.

AWS specifies the opposite compatibility constraint: Gateway Load Balancer target groups used with TGW appliance mode must use 5-tuple flow stickiness, not 2-tuple stickiness.

GWLB flow stickiness hashes network-flow fields to keep packets on an appliance target; it is not an HTTP session cookie feature of an Application Load Balancer.

GENEVE is the required traffic encapsulation between Gateway Load Balancer and its appliance targets. Removing it is not a valid way to change flow-stickiness compatibility.

TGW ingress is evaluated against the associated TGW route table; a VPC route alone cannot resolve the second-hop destination; that addresses TGW route-table entry for an attached destination, rather than manual authorization of cross-account attachments.

Association selects the forwarding lookup table; controlled propagation prevents undesired destination visibility between segmentation domains; this belongs to independent forwarding domains on a common transit hub, while the problem is manual authorization of cross-account attachments.

In the materialized cross-account TGW attachment workflow, resource sharing grants use of the TGW but does not itself connect workload VPCs to the network dataplane; the current case needs manual authorization of cross-account attachments.

TGW ingress is evaluated against the associated TGW route table; a VPC route alone cannot resolve the second-hop destination; that addresses TGW route-table entry for an attached destination, rather than explicit inter-Region TGW route creation.

Inter-Region peering traffic remains on AWS infrastructure and uses inter-Region encryption; application TLS remains separately relevant to end-to-end trust; this belongs to understanding protection boundary of inter-Region peering, while the problem is explicit inter-Region TGW route creation.

Creating a peer relationship does not install the application subnet routes needed for each direction of private IP transit; this changes bidirectional subnet routing for VPC peers, not the necessary explicit inter-Region TGW route creation.

Resource sharing grants use of the TGW but does not itself connect workload VPCs to the network dataplane; that addresses materialized cross-account TGW attachment, rather than correct zonal placement of transit attachment interfaces.

Appliance mode preserves flow-affine AZ handling through the inspection attachment so opposite directions reach the same stateful appliance path; this belongs to flow-symmetric transit inspection, while the problem is correct zonal placement of transit attachment interfaces.

In the association-dependent TGW lookup workflow, the TGW examines only the ingress attachment's associated table when forwarding; propagation into an unrelated table changes no dev path; the current case needs correct zonal placement of transit attachment interfaces.

TGW ingress is evaluated against the associated TGW route table; a VPC route alone cannot resolve the second-hop destination; that addresses TGW route-table entry for an attached destination, rather than deliberate drop action within transit routing.

Transit routing follows longest-prefix match before broad-prefix alternatives, allowing a narrow service segment to take an explicit next hop; this changes specific prefix overrides aggregate traffic steering, not the necessary deliberate drop action within transit routing.

In the correct routing domain for inbound VPN traffic workflow, TGW association determines lookup behavior for packets arriving from the VPN; using the wrong table can expose or suppress destinations; the current case needs deliberate drop action within transit routing.