Dynamic Routing - BGP in VMware NSX-T

Today we are going to discuss about the Dynamic routing capabilities in the VMware NSX-T and the protocol we are going to discuss is BGP- Border Gateway Protocol which is an External routing protocol.

BGP in VMware NSX-T
A typical leaf-spine topology has eBGP running between leaf switches and spine switches. Tier-0 gateways support eBGP and iBGP on the external interfaces with physical routers. BFD can also be enabled per BGP neighbor for faster failover. BFD timers depend on the Edge node type.

Bare metal Edge supports a minimum of 300ms TX/RX BFD keep alive timer while the VM form factor Edge supports a minimum of 1000ms TX/RX BFD keep alive timer. 

Fig 1.1-Dynamic Routing - BGP in VMware NSX-T

Supported BGP protocol in VMware NSX-T environment

  • eBGP multi-hop support, allowing eBGP peering to be established on loopback interfaces.
  • iBGP and eBGP multi-hop BFD
  • ECMP support with BGP neighbors in same or different AS numbers.
  • BGP Allow AS in
  • BGP route aggregation support with the flexibility of advertising a summary route only to the BGP peer or advertise the summary route along with specific routes. A more specific route must be present in the routing table to advertise a summary route.
  • Route redistribution in BGP to advertise Tier-0 and Tier-1 Gateway internal routes.
  • Inbound/outbound route filtering with BGP peer using prefix-lists or route-maps.
  • Influencing BGP path selection by setting Weight, Local preference, AS Path Prepend, or MED.
  • Standard, Extended and Large BGP community support.
  • Graceful restart (Full and Helper mode) in BGP.
  • BGP communities can be set in a route-map to facilitate matching of communities at the upstream router.
  • GP well-known community names (e.g., no-advertise, no-export, no-export-subconfed) can also be included in the BGP route updates to the BGP peer.