DHCP Relay in EVPN-VXLAN

In previous posts, I discussed the construction of an EVPN-VXLAN fabric using Cisco NDFC. A critical aspect often overlooked — and the focus of this post — is the transition from a traditional 3-tier data centre architecture to an EVPN-VXLAN setup. One notable challenge in this transition is the configuration of the DHCP relay. Why DHCP Relay Behaves Differently in EVPN-VXLAN Traditionally, DHCP relays are configured to identify the default gateway using link-selection (DHCP Option 82 sub-option 5), ensuring IP addresses are allocated from the correct scope. ...

December 1, 2023 · 4 min · Gary Wong