Add Campus EVPN-VXLAN fabric configs and host interfaces

- campus-spine1/2 (AS 66000): eBGP underlay + EVPN RR toward leafs
  and border leafs, addressing plan 10.1.x.x.
- campus-leaf1/2 (VTEP1, AS 66001, VTEP 10.1.255.11): VLAN 50
  (stretched L2 VXLAN, VNI 110050) and VLAN 60 (VRF gold anycast
  10.60.60.1, L3 VNI 100001).
- campus-leaf3/4 (VTEP2, AS 66002, VTEP 10.1.255.12): VLAN 50 and
  VLAN 70 (VRF gold anycast 10.60.70.1).
- border-leaf-campus1/2 (AS 66005, VTEP 10.1.255.21): MLAG pair,
  OSPF + eBGP to cores, VRF gold stitched via vxlan vrf gold
  vni 100001 with RT 1:100001.
- campus-access1/2: L2-only uplinks to campus leaf MLAG pairs,
  trunks VLAN 50+60 / 50+70.
- campus-host1/2 interface files: bond0 + VLAN sub-interfaces for
  the stretched L2 VLAN 50 and the VRF gold subnets.

configs/campus-spine2.cfg

@@ -0,0 +1,124 @@
+! Campus-Spine2 Configuration
+! Campus BGP EVPN Spine - AS 66000
+!
+hostname campus-spine2
+!
+! LLDP Management0
+lldp management-address Management0
+!
+! enable gNMI API
+management api gnmi
+   transport grpc default
+   provider eos-native
+!
+! admin/admin for ssh access
+username admin privilege 15 role network-admin secret sha512 $6$xQktFrbdeqEhVzLM$.1wOJB25nw2fqYaSXDu6y4mo6AP9hngMCFe2vGDl84hWoz00Q.4unoEBqspNI0HEoRz.OZhdBHqQv12KABf0B0
+!
+! Enable IP routing
+ip routing
+ip route 100.64.0.0/10 172.16.0.254
+!
+! Enable routing protocols
+service routing protocols model multi-agent
+!
+! Management interface
+interface Management0
+   ip address 172.16.0.21/24
+!
+! Loopback for BGP Router-ID
+interface Loopback0
+   ip address 10.1.250.2/32
+!
+! Underlay P2P interfaces to Campus Leafs
+interface Ethernet1
+   description campus-leaf1
+   no switchport
+   ip address 10.1.2.0/31
+   mtu 9214
+!
+interface Ethernet2
+   description campus-leaf2
+   no switchport
+   ip address 10.1.2.2/31
+   mtu 9214
+!
+interface Ethernet3
+   description campus-leaf3
+   no switchport
+   ip address 10.1.2.4/31
+   mtu 9214
+!
+interface Ethernet4
+   description campus-leaf4
+   no switchport
+   ip address 10.1.2.6/31
+   mtu 9214
+!
+! Underlay P2P interfaces to Campus Border Leafs
+interface Ethernet5
+   description border-leaf-campus1
+   no switchport
+   ip address 10.1.2.8/31
+   mtu 9214
+!
+interface Ethernet6
+   description border-leaf-campus2
+   no switchport
+   ip address 10.1.2.10/31
+   mtu 9214
+!
+! BGP Configuration
+router bgp 66000
+   router-id 10.1.250.2
+   no bgp default ipv4-unicast
+   bgp log-neighbor-changes
+   distance bgp 20 200 200
+   maximum-paths 4 ecmp 64
+   !
+   ! Underlay IPv4 neighbors
+   neighbor 10.1.2.1 remote-as 66001
+   neighbor 10.1.2.3 remote-as 66001
+   neighbor 10.1.2.5 remote-as 66002
+   neighbor 10.1.2.7 remote-as 66002
+   neighbor 10.1.2.9 remote-as 66005
+   neighbor 10.1.2.11 remote-as 66005
+   !
+   ! EVPN peer-group configuration
+   neighbor evpn peer group
+   neighbor evpn next-hop-unchanged
+   neighbor evpn update-source Loopback0
+   neighbor evpn ebgp-multihop 3
+   neighbor evpn send-community extended
+   neighbor evpn maximum-routes 12000 warning-only
+   !
+   ! EVPN neighbors (to campus leaf loopbacks)
+   neighbor 10.1.250.11 peer group evpn
+   neighbor 10.1.250.11 remote-as 66001
+   neighbor 10.1.250.12 peer group evpn
+   neighbor 10.1.250.12 remote-as 66001
+   neighbor 10.1.250.13 peer group evpn
+   neighbor 10.1.250.13 remote-as 66002
+   neighbor 10.1.250.14 peer group evpn
+   neighbor 10.1.250.14 remote-as 66002
+   !
+   ! EVPN neighbors (to campus border-leaf loopbacks)
+   neighbor 10.1.250.21 peer group evpn
+   neighbor 10.1.250.21 remote-as 66005
+   neighbor 10.1.250.22 peer group evpn
+   neighbor 10.1.250.22 remote-as 66005
+   !
+   ! IPv4 address family
+   address-family ipv4
+      neighbor 10.1.2.1 activate
+      neighbor 10.1.2.3 activate
+      neighbor 10.1.2.5 activate
+      neighbor 10.1.2.7 activate
+      neighbor 10.1.2.9 activate
+      neighbor 10.1.2.11 activate
+      network 10.1.250.2/32
+   !
+   ! EVPN address family
+   address-family evpn
+      neighbor evpn activate
+!
+end