garytriv

VxLAN Flood and Learn

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by

garytriv
in

This post is about doing a lab for flood and learn VxLAN deployment, Here the topology I am going to use in EVE-NG PRO

Steps

  1. Basic IP address configuration
  2. OSPF as Underlay
  3. PIM as Underlay (multicast)
  4. VxLAN configuration

—————————————————

Step1 -Basic IP address configuration

————-SPINE1—————————-

config t

host SPINE1

interface e1/1

no sw

ip add 10.1.30.1/30

no shut

interface e1/2

no sw

ip add 10.1.100.1/30

no shut

interface e1/3

no sw

ip add 10.1.101.1/30

no shut

int lo 0

ip add 100.100.100.100/32

no shut

end

copy run start

————-VTEP1—————-

config t

host VTEP1

interface e1/2

no sw

ip add 10.1.100.2/30

no shut

int lo 0

ip add 1.1.1.1/32

no shut

end

copy run start

————-VTEP2——————

config t

host VTEP2

interface e1/3

no sw

ip add 10.1.101.2/30

no shut

int lo 0

ip add 2.2.2.2/32

no shut

end

copy run start

———————————————————-

Step 2- Underlay- OSPF and Multicast

———————————————————

————-SPINE1———————————–

config t

feature ospf

feature pim

feature bgp

router ospf 1

router-id 100.100.100.100

interface Ethernet1/1-3

  ip ospf network point-to-point

  ip router ospf 1 area 0.0.0.0

  ip pim sparse-mode

interface loopback0

  ip ospf network point-to-point

  ip router ospf 1 area 0.0.0.0

  ip pim sparse-mode

end

copy run start

————-VTEP1—————-

config t

feature ospf

feature pim

feature bgp

router ospf 1

  router-id 1.1.1.1

interface loopback0

  ip ospf network point-to-point

  ip router ospf 1 area 0.0.0.0

  ip pim sparse-mode

interface Ethernet1/2

  ip ospf network point-to-point

  ip router ospf 1 area 0.0.0.0

  ip pim sparse-mode

end

copy run start 

————-VTEP2——————

config t

feature ospf

feature pim

feature bgp

router ospf 1

  router-id 2.2.2.2

interface loopback0

  ip ospf network point-to-point

  ip router ospf 1 area 0.0.0.0

  ip pim sparse-mode

interface Ethernet1/3

  ip ospf network point-to-point

  ip router ospf 1 area 0.0.0.0

  ip pim sparse-mode

end

copy run start 

*******Multicast RP on Spine using loopback 0 and put same command on both VTEP’s ***

Config t

ip pim rp-address 100.100.100.100 group-list 239.0.0.0/24 bidir

end

copy run start

Note:

  1. Loopback on SPINE is needed for multicast Rendezvous point (RP) configuration
  2. Loopback on LEAF (Or VTEP) is needed for forming VxLAN neighborship with other VTEP’s

——————————————————————————-

Verification- VTEP1, VTEP2 and SPINE1- all interface, ospf, pim and ospf neighborship should be UP!

——————————————————————————-

——————————————————————————-

VxLAN Configuration for Flood and Learn (no BGP required)

**Remember VxLAN related configuration will only go on VTEP’s (Not on SPINE, as SPINE is just a Transport)

——————————————————————————-

VTEP1 and VTEP2

Config t

! For enabling VxLAN

feature nv overlay

! For VNI/VNID

feature vn-segment-vlan-based

! Associate vlan to vni

vlan 100

    vn-segment 10100

! Associate vni with multicast group

interface nve1

  source-interface loopback0

  member vni 10100

    mcast-group 239.0.0.100

  no shutdown

end

copy run start

Downstream port configuration for Host End device

VTEP1

Note- You need a Layer 3 interface for testing and initiating the VxLAN traffic

Make VTEP your root switch if it is not for your vlan 100- show span vlan 100

config t

spanning-tree vlan 100 priority 4096

end

config t

interface Ethernet1/8 (1/7)

  switchport

  switchport mode trunk

  switchport trunk allowed vlan 100

 no shut

end

copy run start

VTEP2

config t

interface Ethernet1/8

  switchport

  switchport mode trunk

  switchport trunk allowed vlan 100

 no shut

end

copy run start

End host device configuration

Note:

  1. You need a Layer 3 interface for testing and initiating the VxLAN traffic as we are using SW images here
  2. You also need to put a static default route to point next hop as VTEP address as we are using SW images here

HOSTA

config t

host HOSTA

no cdp advertise-v2

Vlan 100

interface e0/0

sw

sw trunk encapsulation dot1q

sw mode trunk

sw trunk allowed vlan 100

no shut

!

interface vlan 100

ip add 192.168.100.10 255.255.255.0

no shut

end

wr

HOSTC

config t

host HOSTC

no cdp advertise-v2

Vlan 100

interface e0/0

sw

sw trunk encapsulation dot1q

sw mode trunk

sw trunk allowed vlan 100

no shut

!

interface vlan 100

ip add 192.168.100.20 255.255.255.0

no shut

end

wr

Commands-

sh nve interface

sh nve peers

sh nve vni

Verification:-

You will not see any peers until there is traffic originated from End host, that the main issues with Flood and Learn, until data plane traffic is initiated, VTEP’s don’t establish peering and learn mac address, noticed in F&L there is no control plane protocol (like BGP) that is running, so after Data plane traffic, control plane functionality is happening, which is peering and mac address learning.

You will only see locally connected host on port 1/8, you are NOT Learning REMOTE VTEP or REMOTE End Host MAC yet!

Issues encountered-

Issues 1- Booting for 1st time or after reboot, you may get into boot loader> prompt,

For Loader prompt, use below command to boot

Loader > boot nxos.9.3.13.bin

To fix it permanently, use below command-– working image-cisco Nexus9000 C9500v Chassis- nxos.9.3.13.bin

config t

boot nxos bootflash:/nxos.9.3.13.bin

Performing image verification and compatibility check, please wait….

copy running-config startup-config

Issues 2- Ran into issue after reboot of VTEP-

VTEP2# show spanning-tree

No spanning tree instance exists.

 if you see this, simply shut/no shut the interface, same for your SVI interface, troubleshoot spanning tree 1st, without that data traffic is not going to work, to enable SPT command is – spanning tree vlan 100

Do basic check as well- show ip int bri, show int status, show spanning tree, show int trunk etc

Issues 3- I tried multiple image for NXOSV both in 9.x train and 10.x train but somehow none work for Flood and Learn, expect this image 9.3.13, ensure you use 95v image (correct image- nexus9500v.9.3.13.qcow2) and not 93v image (nexus9300v.9.3.13.qcow2)

Tip- EVE-PRO

clear browsing cache and history if your Wireshark is having issue to capture packet in eve-ng pro for saving capture, use this location –/nobody/thinclient_drives/GUACFS/Download and this will give you option to save on your local PC location (like download folder), this applies only if you are using Native console to log on to eve-ng (not HTML 5), look at page 206, eve-ng professional cookbook

Hope this post is helpful to do understand the details of Flood and Learn VxLAN deployment, in next post I will cover VxLAN EVPN deployment lab.

Thanks

Gary Triv

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