HPE7-A09 Sample Questions & Answers

Configuring Area 1 as a Totally Stubby Area prevents external (Type 5) and inter-area (Type 3) LSAs from entering the access layer, replacing them with a single default route. This minimizes the LSDB size on access switches. Furthermore, implementing route summarization at the ABR (Distribution) towards the Core prevents specific link flaps in the access layer from triggering SPF calculations in the Core, stabilizing the backbone.

The ISL is a member of all VLANs by default, and the VSX Guide warns that VLANs containing VSX LAG members must not be excluded from the ISL: traffic for single-homed devices, or traffic that arrives on one peer after a downstream link to the other peer fails, has to cross the ISL. Enabling vsx-sync in each VLAN context keeps the VLAN definitions identical on both peers and prevents configuration drift. Excluding VLANs from the ISL, using PVLANs on the ISL or splitting devices into separate VRFs would break these paths.

With VSX active gateway, each peer keeps its own SVI address (here .2 on the primary, another address such as .3 on the secondary) and both peers answer for the shared virtual IP (.1) and virtual MAC, so both route traffic for the default gateway. The VIP and VMAC must be identical on both VSX peers (active-gateway ip mac ), and the SVI needs an IP address in the same subnet. HPE recommends a locally administered unicast VMAC (x2/x6/xA/xE-xx-xx-xx-xx-xx, for example 12:01:00:00:XX:0Y for an aggregation pair) and never the peer system MAC. VRRP cannot be configured on an SVI that uses active gateway, and vsx-sync active-gateways only synchronizes the configuration; it does not create the gateway.

To filter redistributed routes based on tags, a route-map is required. The route-map STATIC-TO-OSPF is defined to match the specific tag 500. This route-map is then applied to the redistribute static command within the OSPF process. This ensures only static routes tagged with 500 are injected into the OSPF domain.

Local Preference is set with a route-map. A standard community list (ip community-list standard ISP-PREF permit 65001:100) matches the community, the route-map references it with match community-list ISP-PREF and applies set local-preference 200, and the route-map is then applied inbound to the ISP neighbor (neighbor route-map SET-LP in). Prefix lists cannot match communities, and weight or router-ID tie-breakers do not act on the community.

On AOS-CX a VTEP is configured with interface vxlan 1, the tunnel source address with source ip (normally the loopback address), no shutdown, and then each L2VNI is created with vni and mapped to its VLAN with vlan inside the VNI context. EVPN (the evpn context with per-VLAN RD/route targets and the BGP address-family l2vpn evpn) then advertises the VNI; it does not perform the VNI-to-VLAN mapping itself.