EVPN/VXLAN support on Cat8000v, IOL, IOLL2

[ipspace]

Limitations:

• No support for symmetric IRB

[ipspace]

@DanPartelly -- in case you want to try it out. Symmetric IRB coming as soon as I overcome my disgust at the fact that they expect us to configure an explicit VLAN for the transit VNI.

[Copilot]

Pull request overview

Adds EVPN/VXLAN support for Cisco IOS/XE-based virtual platforms (Catalyst 8000v, IOL, IOLL2), with documented limitations (notably no symmetric IRB) and updated platform capability matrices.

Changes:

• Extend IOS BGP session extras to include the L2VPN EVPN address-family neighbor knobs.
• Add IOS/XE EVPN templates (common control-plane + platform-specific dataplane) and adjust IOS VXLAN template for EVPN-based flooding.
• Update device feature flags and documentation tables/caveats to reflect EVPN/VXLAN support and limitations on Cat8000v and IOL/IOLL2.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
netsim/extra/bgp.session/ios.j2	Adds EVPN address-family handling in the BGP session “extra” template for IOS.
netsim/devices/iol.yml	Declares VXLAN dependency on EVPN and EVPN asymmetric-IRB capability/limitations for IOL.
netsim/devices/cat8000v.yml	Declares EVPN asymmetric-IRB capability/limitations for Catalyst 8000v.
netsim/ansible/templates/vxlan/ios.j2	Switches NVE config behavior depending on whether flooding is EVPN-based vs static replication.
netsim/ansible/templates/evpn/ios.j2	New IOS/XE EVPN dataplane template (bridge-domain-based platforms).
netsim/ansible/templates/evpn/ios-common.j2	New shared IOS/XE EVPN control-plane + MAC-VRF config (BGP + EVPN instance).
netsim/ansible/templates/evpn/ioll2.j2	New IOLL2-specific EVPN dataplane template using vlan configuration.
docs/platforms.md	Updates platform support matrices to mark Cat8000v and IOL/IOLL2 EVPN-capable.
docs/module/vxlan.md	Documents VXLAN feature support for IOL/IOLL2 (with caveat link).
docs/module/evpn.md	Documents IOS/XE EVPN support (Cat8000v/IOL/IOLL2) and limitations via footnote and tables.
docs/caveats.md	Adds IOL/IOLL2 caveats relevant to VXLAN/EVPN (MTU + static replication limitation).

[DanPartelly]

On IOL 17.16.01 I have been unable to get it to work. Even in a simple scenario. I'll run relevant tests tomorrow and see what the heck is going on on my side, as I'm sure you have run tests already, so the problem should be here.

[ipspace]

On IOL 17.16.01 I have been unable to get it to work.

I got that lab's solution.yml topology working with vrnetlab/cisco_iol:17.16.01a

as I'm sure you have run tests already

All of them, on all three platforms. Do keep in mind that VXLAN only works with EVPN

[DanPartelly]

Definitely a problem on my side, then.

Yes, I saw the notes. I've only run scenarios with EVPN as the control plane, and I haven't attempted anything with a static ingress list. Netlab will catch those scenarios anyway, for it requires EVPN for VXLAN on the platform. I have tried solution.yml as well (it did not work here), to make sure I didn't mess up the configuration, but the results are the same and the config is identical for all practical purposes.

Now I have to deal with another conundrum.

[DanPartelly]

Valid VNI range on Cisco IOL/IOl2 is 4096-16,777,215. And probably on other cisco devices as well.

We need some quirks to account for this.

s1(config-if)#member vni 1000 in
s1(config-if)#member vni 1000 ingress-replication ?
local-routing Enable vxlan centralized gateway forwarding for routed traffic

s1(config-if)#member vni 1000 ingress-replication
% Valid VNI Range is 4096-16777215.