A customer has a network: 10.0.0.0/24. The gateway 10.0.0.1/24 is represented by an SVI for VLAN 10 on a core switch. Downstream there is an ACE Load balancer, which has a BVI. This BVI's IP address is 10.0.0.4/24 and bridges two VLAN's 20 and 30.
New applications are all build in the same /24. The VIP IP allocate for these new apps also is assigned from the same /24. As an example:
!-- Example application !-- Frontend VIP IP 10.0.0.7 !-- Backend Servers 10.0.0.8 10.0.0.9
In ARP in the Core, the SVI is (obviously) part of VLAN 10, however, the same IP is shown belonging to VLAN 20 down in the ACE per ARP. VIP IP's show up in VLAN 20, backend servers show up in VLAN 30. All the same /24.
!-- SVI in the core Interface Vlan10 ip address 10.0.0.2/24 hsrp version 2 hsrp 10 preempt ip 10.0.0.1 no shut !-- Sh ip arp output (simulated) 10.0.0.1 - 0000.0cxx.xxxx vlan10 10.0.0.2 - xxxx.xxxx.xxxx vlan10 !-- Int/BVI config in the ACE interface vlan 20 bridge-group 20 no normalization mac-sticky enable no icmp-guard service-policy input VIP-policy no shut Interface vlan 30 bridge-group 20 no normalization mac-sticky enable no icmp-guard service-policy input backend-server-policy no shut Interface bvi 20 ip address 10.0.0.5 255.255.255.0 alias 10.0.0.4 255.255.255.0 peer ip address 10.0.0.6 255.255.255.0 no shut !-- Sh arp output (simulated) 10.0.0.1 0000.0cxx.xxxx vlan20 10.0.0.4 xxxx.xxxx.xxxx bvi20 10.0.0.7 xxxx.xxxx.xxxx vlan20 10.0.0.8 xxxx.xxxx.xxxx vlan30 10.0.0.9 xxxx.xxxx.xxxx vlan30
How does this work (It does by the way)? Specifically from a tagging perspective, how is it possible for the traffic to move from the endpoint through the LB and the core successfully? Again, the only bridging is internal to the LB, not between the LB and anything else.