Add Tunnel support for EOS

docs/caveats.md

@@ -56,6 +56,12 @@ nodes:
 * Arista EOS virtual machines and containers use [proprietary control-plane messages to indicate the loss of Ethernet line protocol](https://blog.ipspace.net/2025/03/arista-spooky-action-distance/). Set the **netlab_phy_control** node variable to *False* to disable this functionality.
 * Device configurations that contain `no lldp transmit` or `no lldp receive` configuration command trigger configuration reload failures due to an Arista EOS bug ([more details](https://github.com/ipspace/netlab/issues/2577)). These commands are thus automatically removed from collected device configurations.
 
+GRE tunnel caveats:
+
+* OSPFv2 routing process does not use routes reachable over tunnel interfaces unless the **tunnel routes** parameter is configured. _netlab_ enables OSPFv2 tunnel routes, as no other routing protocol has a similar limitation, and Arista EOS documentation claims it's enabled by default (which is not the case).
+* IS-IS does not work over GRE tunnels
+* Arista cEOS might forward multiple copies of the packets received over GRE tunnels
+
 (caveats-aruba)=
 ## Aruba AOS-CX
 

docs/plugins/tunnel.gre.md

@@ -9,6 +9,7 @@ The plugin includes Jinja2 templates for the following platforms:
 
 | Operating system    | GRE over<br>IPv4 | GRE over<br>IPv6 | Transport<br>VRF |
 |--------------|:-:|:-:|:-:|
+| Arista EOS          | ✅ | ❌ | ✅ |
 | Cisco IOS/XE[^18v] |✅|✅|✅|
 | FRR                 |✅|✅|✅|
 | Juniper vJunos-switch |✅|✅|✅|

netsim/ansible/templates/ospf/eos.ospfv2.j2

@@ -16,6 +16,7 @@ router ospf {{ ospf_pid }}
 {% if ospf_data.router_id is defined %}
  router-id {{ ospf_data.router_id }}
 {% endif %}
+ tunnel routes
  interface unnumbered hello mask tx 0.0.0.0
  timers spf delay initial 100 200 500
  timers lsa rx min interval 100

netsim/devices/eos.yml

@@ -140,6 +140,8 @@ features:
     supported_protocols: [ stp, rstp, mstp, pvrst ]
     enable_per_port: True
     port_type: True
+  tunnel:
+    gre: [ ipv4, vrf ]
   vlan:
     model: l3-switch
     native_routed: true

netsim/extra/tunnel/gre/eos.j2

@@ -0,0 +1,12 @@
+{% for intf in netlab_interfaces if intf.tunnel.mode|default('') in ['gre'] %}
+!
+interface {{ intf.ifname }}
+  tunnel mode {{ intf.tunnel.mode }}
+{%   if intf.tunnel.vrf is defined %}
+  tunnel underlay vrf {{ intf.tunnel.vrf }}
+{%   endif %}
+  tunnel source {{ intf.tunnel._source[intf.tunnel.af] }}
+  tunnel destination {{ intf.tunnel._destination[intf.tunnel.af] }}
+  tunnel path-mtu-discovery
+  tunnel ttl 255
+{% endfor %}