Source code

In the last post we built the underlay for the VXLAN topology below.

Topology

VXLAN

IP Addresses

Device Interface IP <> Device Interface IP
spine01 eth1 172.16.0.1/30 <> leaf01 eth1 172.16.0.2/30
spine01 eth2 172.16.0.5/30 <> leaf02 eth1 172.16.0.6/30
spine01 eth3 172.16.0.9/30 <> leaf03 eth1 172.16.0.10/30
spine01 eth4 172.16.0.13/30 <> leaf04 eth1 172.16.0.14/30
spine01 lo0 192.168.0.1/32
spine02 eth1 172.17.0.1/30 <> leaf01 eth2 172.17.0.2/30
spine02 eth2 172.17.0.5/30 <> leaf02 eth2 172.17.0.6/30
spine02 eth3 172.17.0.9/30 <> leaf03 eth2 172.17.0.10/30
spine02 eth4 172.17.0.13/30 <> leaf04 eth2 172.17.0.14/30
spine02 lo0 192.168.0.2/32
leaf01 po12 10.12.12.1/30 <> leaf02 po12 10.12.12.2/30
leaf01 lo0 192.168.1.1/32
leaf02 lo0 192.168.1.2/32
leaf03 lo0 192.168.1.3/32
leaf04 lo0 192.168.1.4/32

We are going add two vlans with layer 3 subnets to the overlay. We also need to add a loopback interface to act as the tunnel source interface. We will advertise this interface into BGP.

Device VLAN Subnet Interface IP VIP
leaf01 100 10.100.100.0/24 Vlan100 10.100.100.1 10.100.100.254
leaf02 100 10.100.100.0/24 Vlan100 10.100.100.2 10.100.100.254
leaf03 100 10.100.100.0/24 Vlan100 10.100.100.3 10.100.100.254
leaf04 100 10.100.100.0/24 Vlan100 10.100.100.4 10.100.100.254
leaf01 200 10.200.200.0/24 Vlan200 10.200.200.1 10.200.200.254
leaf02 200 10.200.200.0/24 Vlan200 10.200.200.2 10.200.200.254
leaf03 200 10.200.200.0/24 Vlan200 10.200.200.3 10.200.200.254
leaf04 200 10.200.200.0/24 Vlan200 10.200.200.4 10.200.200.254
leaf01 - 10.12.34.1/32 lo1 10.12.34.1 -
leaf02 - 10.12.34.1/32 lo1 10.12.34.1 -
leaf03 - 10.12.34.3/32 lo1 10.12.34.3 -
leaf04 - 10.12.34.4/32 lo1 10.12.34.4 -

The changes to the host_vars since the last post are listed below.

leaf01.yml 

---

--snip--

interfaces:

--snip--

    # Start Overlay
  - name: Loopback1
    description: vni-source
    ipv4: 10.12.34.1/32
    shutdown: False
  - name: Vxlan1
    description: vti
    shutdown: False
    vnisource: Loopback1
    vxlanvlan:
      - vlan: 100
        vni: 100
        flood: 
          - 10.12.34.3
            10.12.34.4
      - vlan: 200
        vni: 200
        flood: 
          - 10.12.34.3
            10.12.34.4

--snip---

bgp:
  asn: 65001
  routerid: 192.168.1.1
  distance: 20 200 200
  maxpaths: 2 ecmp 2
  networks: 
    - 192.168.1.1/32
    # Start Overlay
    - 10.12.34.1/32

--snip--

leaf02.yml 

---

--snip--

interfaces:

--snip--

  # Start Overlay
  - name: Loopback1
    description: vni-source
    ipv4: 10.12.34.1/32
    shutdown: False
  - name: Vxlan1
    description: vti
    shutdown: False
    vnisource: Loopback1
    vxlanvlan:
      - vlan: 100
        vni: 100
        flood: 
          - 10.12.34.3
            10.12.34.4
      - vlan: 200
        vni: 200
        flood: 
          - 10.12.34.3
            10.12.34.4

--snip---

bgp:
  asn: 65001
  routerid: 192.168.1.2
  distance: 20 200 200
  maxpaths: 2 ecmp 2
  networks: 
    - 192.168.1.2/32
    # Start Overlay
    - 10.12.34.1/32

--snip--

leaf03.yml 

---

--snip--

interfaces:

--snip--

  # Start Overlay
  - name: Loopback1
    description: vni-source
    ipv4: 10.12.34.3/32
    shutdown: False
  - name: Vxlan1
    description: vti
    shutdown: False
    vnisource: Loopback1
    vxlanvlan:
      - vlan: 100
        vni: 100
        flood: 
          - 10.12.34.1
            10.12.34.4
      - vlan: 200
        vni: 200
        flood:
          - 10.12.34.1
            10.12.34.4

--snip---

bgp:
  asn: 65002
  routerid: 192.168.1.3
  distance: 20 200 200
  maxpaths: 2 ecmp 2
  networks:
    - 192.168.1.3/32
    # Start Overlay
    - 10.12.34.3/32

--snip--

leaf04.yml 

---

--snip--

interfaces:

--snip--

    # Start Overlay  
  - name: Loopback1
    description: vni-source
    ipv4: 10.12.34.4/32
    shutdown: False
  - name: Vxlan1
    description: vti
    shutdown: False
    vnisource: Loopback1
    vxlanvlan:
      - vlan: 100
        vni: 100
        flood: 
          - 10.12.34.1
            10.12.34.3
      - vlan: 200
        vni: 200
        flood: 
          - 10.12.34.1
            10.12.34.3

--snip---

bgp:
  asn: 65003
  routerid: 192.168.1.4
  distance: 20 200 200
  maxpaths: 2 ecmp 2
  networks: 
    - 192.168.1.4/32
     # Start Overlay
    - 10.12.34.4/32

--snip--

We have to add the loopbacks to the prefixlist or they will not be advertised.

---



prefixlists:
  - name: to-spines
    seq: 10
    action: permit
    ipv4: 192.168.0.0/23
    eq: 32
  - name: to-spines
    seq: 20
    action: permit
    ipv4: 172.16.0.0/23
    eq: 30
  - name: to-spines
    seq: 30
    action: permit
    ipv4: 10.12.12.0/30
    eq: 30
  # Start Overlay
  - name: to-spines
    seq: 40
    action: permit
    ipv4: 10.12.34.0/24
    eq: 32

There are only a few changes to the template.

eos-vxlan.j2

ip routing
!

--snip--

{% if interface.vnisource is defined %}
   vxlan source-interface {{ interface.vnisource }}
{% endif -%}
{% if interface.vxlanvlan is defined %}
{% for vxvlan in interface.vxlanvlan %}
   vxlan vlan {{ vxvlan.vlan }} vni {{ vxvlan.vni }}
{% if vxvlan.flood is defined %}
{% for vtep in vxvlan.flood %}
   vxlan vlan {{ vxvlan.vlan }} flood vtep {{ vtep }}
{% endfor -%}
{% endif -%}
{% endfor -%}
{% endif -%}
!

--snip--

The playbook will not change at all.

vxlan-playbook.yml

---

  - hosts: eos
    gather_facts: no

    tasks:
      
    - name: Create configuration files
      template:
        src: "templates/{{ ansible_network_os }}-vxlan.j2"
        dest: "configs/{{ inventory_hostname }}-vxlan.config"
      tags: 
        - template

    - name: Load configuration file
      eos_config:
        backup: yes
        src: "configs/{{ inventory_hostname }}-vxlan.config"
        defaults: true
        save_when: modified
      register: "{{ inventory_hostname }}"
      tags:
        - configpush

Running the playbook only changes the leafs.

netops@netserver:~/git/vxlanansible/ansible$ ansible-playbook vxlan-playbook.yml 

PLAY [eos] *****************************************************************************************************

TASK [Create configuration files] ******************************************************************************
ok: [leaf01]
ok: [spine01]
ok: [leaf02]
ok: [leaf03]
ok: [spine02]
ok: [leaf04]

TASK [Load configuration file] *********************************************************************************
ok: [spine01]
ok: [spine02]
changed: [leaf03]
changed: [leaf02]
changed: [leaf01]
changed: [leaf04]

PLAY RECAP *****************************************************************************************************
leaf01                     : ok=2    changed=1    unreachable=0    failed=0   
leaf02                     : ok=2    changed=1    unreachable=0    failed=0   
leaf03                     : ok=2    changed=1    unreachable=0    failed=0   
leaf04                     : ok=2    changed=1    unreachable=0    failed=0   
spine01                    : ok=2    changed=0    unreachable=0    failed=0   
spine02                    : ok=2    changed=0    unreachable=0    failed=0

Lets take a look at the config on leaf01 and leaf03 relevant to the overlay.

leaf01

!
vlan 100
   name operations
!
vlan 200
   name staff
!
interface Vlan100
   description operations
   ip address 10.100.100.1/24
   no shutdown
   ip virtual-router address 10.100.100.254
!
interface Vlan200
   description staff
   ip address 10.200.200.1/24
   no shutdown
   ip virtual-router address 10.200.200.254
!
interface Loopback1
   description vni-source
   ip address 10.12.34.1/32
   no shutdown
!
interface Vxlan1
   description vti
   no shutdown
   vxlan source-interface Loopback1
   vxlan vlan 100 vni 100
   vxlan vlan 100 flood vtep 10.12.34.3 10.12.34.4
   vxlan vlan 200 vni 200
   vxlan vlan 200 flood vtep 10.12.34.3 10.12.34.4
!
ip prefix-list to-spines seq 40 permit 10.12.34.0/24 eq 32
!
router bgp 65001
--snip--

   network 10.12.34.1/32
!

leaf03

vlan 100
   name operations
!
vlan 200
   name staff
!
interface Vlan100
   description operations
   ip address 10.100.100.3/24
   no shutdown
!
interface Vlan200
   description staff
   ip address 10.200.200.3/24
   no shutdown
!
interface Loopback1
   description vni-source
   ip address 10.12.34.3/32
   no shutdown
!
interface Vxlan1
   description vti
   no shutdown
   vxlan source-interface Loopback1
   vxlan vlan 100 vni 100
   vxlan vlan 100 flood vtep 10.12.34.1 10.12.34.4
   vxlan vlan 200 vni 200
   vxlan vlan 200 flood vtep 10.12.34.1 10.12.34.4
!
ip virtual-router mac-address aa:00:bb:11:cc:22
!
ip prefix-list to-spines seq 10 permit 192.168.0.0/23 eq 32
!
router bgp 65002
--snip--

   network 10.12.34.3/32
!

Now to test a few things.

leaf01#ping 10.100.100.3 repeat 1
PING 10.100.100.3 (10.100.100.3) 72(100) bytes of data.
80 bytes from 10.100.100.3: icmp_seq=1 ttl=64 time=50.6 ms

--- 10.100.100.3 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 50.609/50.609/50.609/0.000 ms

leaf01#show arp 
Address         Age (min)  Hardware Addr   Interface
172.16.0.1            N/A  5000.00d7.ee0b  Ethernet1
172.17.0.1            N/A  5000.00cb.38c2  Ethernet2
10.100.100.3          N/A  5000.0015.f4e8  Vlan100, Vxlan1
10.100.100.4          N/A  5000.0072.8b31  Vlan100, not learned
10.12.12.2            N/A  5000.0003.3766  Vlan4094, Port-Channel12

Address         Age (min)  Hardware Addr   Interface
172.16.0.9            N/A  5000.00d7.ee0b  Ethernet1
172.17.0.9            N/A  5000.00cb.38c2  Ethernet2
10.100.100.1          N/A  5000.00d5.5dc0  Vlan100, Vxlan1

leaf03#ping 10.200.200.1 repeat 1
PING 10.200.200.1 (10.200.200.1) 72(100) bytes of data.
80 bytes from 10.200.200.1: icmp_seq=1 ttl=64 time=46.6 ms

--- 10.200.200.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 46.697/46.697/46.697/0.000 ms

leaf03#show vxlan address-table 
          Vxlan Mac Address Table
----------------------------------------------------------------------

VLAN  Mac Address     Type     Prt  VTEP             Moves   Last Move
----  -----------     ----     ---  ----             -----   ---------
 100  5000.00d5.5dc0  DYNAMIC  Vx1  10.12.34.1       1       0:04:23 ago
 200  5000.00d5.5dc0  DYNAMIC  Vx1  10.12.34.1       1       0:00:43 ago
Total Remote Mac Addresses for this criterion: 2

Everything looks good. To me this is a really cool thing for those times you need to extend layer 2 or more likely are forced to. The full source code can be found here.