vcenter distributed plugin: vmware dvswitch sometimes ceases forwarding dhcp packets from guest vm to vrouter

[Sandip Dey]

Build R5.0 284

1.Created a virtual network manually
2.Launched 10 vms on the portgroup at a time through a script,without waiting one by one to come up.
3.All of them powered on.
4.Some of the vms did not get ip.
5.While debugging, it was found that th dvswitch did not forward the dhcp packet to vrouter.
6.Its seen on bulk vm migration as well

Its a vmware bug.
Reproducibility: 2/10

WA:
Triger some chamge to the portgroup.I specifically did the following
portgroup--->edit settings--->security--->Promiscus mode--->accept---->ok
then
portgroup--->edit settings--->security--->Promiscus mode--->reject---->ok

This trigger caused the dvswitch to start forwarding the the dvswitch and everything was fine.

[Sachchidanand Vaidya (vaidyasd)]

Sandip,
    Can you try this test with latest code since CVM has a check for ENABLED state of port before assiging VLAN on it.

[Jeba Paulaiyan (jebap)]

Notes:

While bulk VM launch or VM migration on vcenter cluster, it is observed that sometimes vmware dvswitch sometimes ceases forwarding dhcp packets from guest vm to vrouter.

Workaround:

Triger some chamge to the portgroup. For example:

portgroup--->edit settings--->security--->Promiscus mode--->accept---->ok
then
portgroup--->edit settings--->security--->Promiscus mode--->reject---->ok

This trigger causes the dvswitch to start forwarding.

[Luke Bockelmann (h-luke)]

Sandip, did you try what Sachin was asking? It would be good to confirm before I engage VMWare. Thank you!