IPSec vlan firewall rules

[voxel]

I have three sites, A, B and C where B and C are connected to A using ipsec vti.
Each site has a 10.0.0.0/16 subnet and all vlans have /24 subnets with matching id, for example 10.10.10.0/24 for site A and vlan id 10.
Site A is the "hub" and has all the firewall rules in place for each vlan interface.

Is there any way I can avoid re-writing all the firewall rules for the incoming ipsec traffic with matching vlan subnets?
Can I route the ipsec traffic of a specific source (10.20.10.0/24) to an existing vlan interface (10.10.10.0/24) to use the same outgoing rules?

[stephenw10]

Might need a diagram here.

What rules do you think you will need to re-write and why?
You have just added those VLANs?

You can policy route traffic on the IPSec firewall rules. Unclear exactly what you're trying to achieve.

Steve

[voxel]

@stephenw10
No problem, I'll try and write a better example. Please note that in reality there are more than 2 sites and more than 2 vlan's/subnet's at each site. I know VLAN tags don't traverse the ipsec tunnel. I just use them below as subnet identifiers.

Site A (10.10.0.0/16)
On site A all my clients are on VLAN 20 (10.10.20.0/24) and what ever resources they need on VLAN 10 (10.10.10.0/24).
Only certain ports are open to VLAN 10 from VLAN 20.

Site B (10.20.0.0/16)
On site B all my clients are also on VLAN 20 (10.20.20.0/24) and they connect to site A through an IPSec VTI tunnel.
They are the same type of clients as on site A and need access to the same resources on site A's VLAN 10.

In order to allow them access I should (if i'm not mistaken) add pass rules for the specific ports to the site A firewall under the ipsec tab with source 10.20.20.0/24 and destination 10.10.10.0/24.

The issue
Everything is working so that's not the issue. My problem is that i don't want to manage firewall settings on site A for both the VLAN 20 interface and the site B VLAN 20 traffic on the IPSEC tab.
I want 1 firewall rule that handles both.

Guessing now that this could be handled with floating rules instead of interface rules on site A?
For example, a floating pass rule on site A for interface VLAN 20 and IPSEC with source alias of all subnets at each site that are considered "vlan 20".

[stephenw10]

You could do this using an alias with all the client subnets in it and then use that as the source in the firewall rule at site A on the IPSec tab.
That wouldn't filter clients that are at site A that don't use tunnel so you'd still need a rule on the client VLAN there directly.
Or as you say you could put that rule as floating outbound on the resources VLAN at site A.