BusyBox ifup translates 'gateway X' into 'ip route add default via X'
and aborts the whole ifup run with RC=1 when that command fails with
'File exists' — which always happens on first boot because the docker
management bridge has already installed its own default via eth0. As a
result the 'post-up ip route replace default' was never executed and
the host kept the management default.
Remove the 'gateway' line so ifup only runs the idempotent 'post-up ip
route replace default via <fabric-gw>' and the fabric default wins.
Make hosts/campus-host{1,2}_interfaces the source of truth for the
campus host IP and default route, and have clab simply invoke 'ifup
eth1' at container start to apply it. Previously the bound interfaces
file was unused and the real config lived in the YAML exec block,
which was misleading.
BusyBox ifup in the network-multitool image needs 'address' plus
'netmask' rather than a CIDR, so split the address accordingly. Also
add 'post-up ip route replace default via <fabric-gw>' so the fabric
default overrides the management DHCP default even when one is already
installed.
The 'ip route add default via <fabric-gw>' exec command silently failed
on campus-host1 and campus-host2 because the management DHCP on eth0
had already installed a default via 172.16.0.254. As a result, traffic
leaving the host for other fabric subnets was sent out the management
interface instead of the EVPN fabric, breaking end-to-end ping.
Switch to 'ip route replace' so the fabric gateway overrides whatever
default is installed at container start.
With 'no bgp default ipv4-unicast' set at the router level, VRF gold
eBGP/iBGP neighbors were establishing but not exchanging any IPv4
prefixes, breaking inter-fabric transit between DC and Campus. Add an
explicit 'address-family ipv4' block with 'neighbor X activate' under
'vrf gold' on both cores and all four border leafs.
Also drop 'redistribute learned' from the border leaf VRF gold stanza:
it is not a valid command in that context and was silently stripped by
EOS.
- README: rewritten node inventory, AS map, addressing plan
(management, Lo0/Lo1, P2P, hosts), VNI/RD/RT tables, control-plane
summary and end-to-end Campus <-> DC test procedures through the
Core (VRF gold stitching).
- hosts/README: document the two new Campus host configurations.
- assets/arista-evpn-fabric.svg: new three-zone layout (Campus, Core,
DC) with legend.
- evpn-lab.clab.yml.annotations.json: reposition nodes and add zone
labels so the ContainerLab graph matches the extended topology.
core1/core2 provide L3 transit between DC and Campus fabrics. Each
physical link toward a Border Leaf is subinterfaced (.100 default,
.200 VRF gold). OSPF area 0 in default VRF, eBGP to DC BLs (65005)
and Campus BLs (66005), iBGP between core1 and core2 via Loopback0.
VRF gold uses redistribute connected and VRF-aware eBGP sessions on
.200 subinterfaces to stitch VRF gold end-to-end across fabrics.
Both border leafs share VTEP Loopback1 10.0.255.15 and peer with DC
spines in eBGP IPv4 + EVPN. Uplinks to core1/core2 use dot1q
subinterfaces (.100 default underlay, .200 VRF gold) with OSPF area 0
and eBGP to AS 65500. VRF gold extended via vxlan vrf gold vni 100001
with RD <Lo0>:1 and RT 1:100001.
