All about virtual networking

NCP is the container plugin for NSXT, there could be number of articles about NCP architecture already existing, I intend to cover only the areas that lack coverage, example hyperbus internals in upcoming posts. In this post we will see what happens on NSXT side when you create resources on the kubernetes side. To ramp-up let me give a quick intro about NCP components. NCP pod: This is the core piece of NCP solution. It watches k8s events and talks to NSXT MP to facilitate the resource creation. It can run as a pod or as a process(in PKS environments) Nsx-Node-agent: Node-agent is an infra pod(this can also run as a process), runs as a daemonset .so each nodevm will get a replica of node-agent pod. As of NCP 2.5 It has 3 containers/components .   i) nsx-node-agent   ii)nsx-kube-proxy   iii) nsx-ovs nsx-node-agent container takes care of plumbing the network interfaces onto workload pods. nsx-kube-proxy watches service creation events from k8s api and progr...

Recently one of my peers from Sales team reached out and said that he encountered a weird problem during a NSXT customer POC. Problem statement as follows. 1. DHCP didnt work 2. N-S traffic fails intermittently. rebooting the edge remediate the issue short-term. Product versions: NSXT 2.4 ESXi 6.7U2 In his internal lab he deployed a similar topology[Pic1] where he could not recreate the issue. Pic1 Started debugging the dhcp issue, my initial observations below i)   D HCPREQUEST   never reaches the edge (dhcp service port on T1). But the geneve tunnels between edge and hypervisor is up, DFW allows the dhcp traffic as well. ii) Tried assigning a static ip to the dhcptest(client) vm - 192.168.2.3 and pinged the dhcp server ip -192.168.2.2 , didn’t work(desitnation not reachable messages were seen).  iii)  Did a traceflow between vm ip and the dhcp server ip(Pic2), this went through fine!!.  Traffic reached DHCP server , reply ...