Sunday, February 7, 2021

vSphere with Tanzu using NSX-T - Part4 - Tier-0 Gateway and BGP peering

In the previous posts we discussed the following: 

Part1: Prerequisites
Part2: Configure NSX-T
Part3: Edge Cluster


The next step is to create a Tier-0 Gateway, configure its interfaces, and BGP peer with the L3 TOR switches. Following is a high-level logical representation of this configuration:


Configure Tier-0 Gateway


Before creating the T0-Gateway, we need to create two segments.

  • Add Segments.
    • Create a segment "ls-uplink-v54"
      • VLAN: 54
      • Transport Zone: "edge-vlan-tz"
    • Create a segment "ls-uplink-v55"
      • VLAN: 55
      • Transport Zone: "edge-vlan-tz"

  • Add Tier-0 Gateway.
    • Provide the necessary details as shown below.

    • Add 4 interfaces and configure them as per the logical diagram given above.
      • edge-01-uplink1 - 192.168.54.254/24 - connected via segment ls-uplink-v54
      • edge-01-uplink2 - 192.168.55.254/24 - connected via segment ls-uplink-v55

      • edge-02-uplink1 - 192.168.54.253/24 - connected via segment ls-uplink-v54
      • edge-02-uplink2 - 192.168.55.253/24 - connected via segment ls-uplink-v55
    • Verify the status is showing success for all the 4 interfaces that you added.

  • Routing and multicast settings of T0 are as follows:

    • You can see a static route is configured. The next hop for the default route 0.0.0.0/0 is set to 192.168.54.1. 

    • The next hop configuration is given below.

  • BGP settings of T0 are shown below.

    • BGP Neighbor config:

    • Verify the status is showing success for the two BGP Neighbors that you added.

  • Route re-distribution settings of T0:

    • Add route re-distribution.
    • Set route re-distribution.

Now, the T0 configuration is complete. The next step is to configure BGP on the Dell S4048-ON TOR switches.

Configure TOR Switches


---On TOR A---
conf
router bgp 65500
neighbor 192.168.54.254 remote-as 65400
#peering to T0 edge-01 interface
neighbor 192.168.54.254 no shutdown
neighbor 192.168.54.253 remote-as 65400
#peering to T0 edge-02 interface
neighbor 192.168.54.253 no shutdown
neighbor 192.168.54.3 remote-as 65500
#peering to TOR B in VLAN 54
neighbor 192.168.54.3 no shutdown
maximum-paths ebgp 4
maximum-paths ibgp 4


---On TOR B---
conf
router bgp 65500
neighbor 192.168.55.254 remote-as 65400
#peering to T0 edge-01 interface
neighbor 192.168.55.254 no shutdown
neighbor 192.168.55.253 remote-as 65400
#peering to T0 edge-02 interface
neighbor 192.168.55.253 no shutdown
neighbor 192.168.54.2 remote-as 65500
#peering to TOR A in VLAN 54
neighbor 192.168.54.2 no shutdown
maximum-paths ebgp 4
maximum-paths ibgp 4


---Advertising ESXi mgmt and VM traffic networks in BGP on both TORs---

conf
router bgp 65500
network 192.168.41.0/24
network 192.168.43.0/24


Thanks to my friend and vExpert Harikrishnan @hari5611 for helping me with the T0 configs and BGP peering on TORs. Do check out his blog https://vxplanet.com/


Verify BGP Configurations


The next step is to verify the BGP configs on TORs using the following commands:

show running-config bgp

show ip bgp summary

show ip bgp neighbors


Follow the VMware documentation to verify the BGP connections from a Tier-0 Service Router. In the below screenshot you can see that both Edge nodes have the BGP neighbors 192.168.54.2 and 192.168.55.3 with state Estab.


In the next article, I will talk about adding a T1 Gateway, adding new segments for apps, connecting VMs to the segments, and verify connectivity to different internal and external networks. I hope this was useful. Cheers!