NSX-T EVPN - Traffic from VNF to DCGW is dropped every 10 minutes as the Type-2 route is withdrawn from Edge

Products

• VMware NSX Networking

Issue/Introduction

Symptoms:

• Traffic from VNF (Virtual Network Function) to DCGW (Data Centre Gateway) is dropped every 10 minutes for one second or less.
• The default IP Discovery profile is set on the segments with a default timeout of 10 minutes.
• /var/log/syslog on edge shows the ARP being removed and created every 10 minutes.

2023-03-21T00:35:45.635Z sesbg-nf272bm03 NSX 8598 SWITCHING [nsx@6876 comp="nsx-edge" subcomp="datapathd" s2comp="neigh" tname="dp-ipc31" level="INFO"] dynamic arp entry(1107afc9-89ce-41af-9b1e-f7c38f82faaa, 192.168.10.19) is removed
2023-03-21T00:35:46.040Z sesbg-nf272bm03 NSX 8598 SWITCHING [nsx@6876 comp="nsx-edge" subcomp="datapathd" s2comp="neigh" tname="dp-learning3" level="INFO"] dynamic arp entry(1107afc9-89ce-41af-9b1e-f7c38f82faaa, 192.168.10.19) is created
2023-03-21T00:45:46.812Z sesbg-nf272bm03 NSX 8598 SWITCHING [nsx@6876 comp="nsx-edge" subcomp="datapathd" s2comp="neigh" tname="dp-ipc31" level="INFO"] dynamic arp entry(1107afc9-89ce-41af-9b1e-f7c38f82faaa, 192.168.10.19) is removed
2023-03-21T00:45:47.255Z sesbg-nf272bm03 NSX 8598 SWITCHING [nsx@6876 comp="nsx-edge" subcomp="datapathd" s2comp="neigh" tname="dp-learning3" level="INFO"] dynamic arp entry(1107afc9-89ce-41af-9b1e-f7c38f82faaa, 192.168.10.19) is created

Environment

VMware NSX-T Data Center 3.x
VMware NSX-T Data Center
VMware NSX-T Data Center 4.x

Cause

Edge DP probs ARP every 10 minutes. IP Discovery profile is also set to 10 minutes. So IP-MAC is expired at the 10th minute and is learned immediately. However, this can still create fluctuation in the traffic.

Resolution

There is currently no fix for this issue.

Workaround:

Create the new IP Discovery profile with a timeout value of 20 minutes. Then change the segment’s default IP Discovery to the new profile. Alternatively set the VNF ARP timer to less than 10 minutes.