one way slowness issue to Azure

[alvinaung]

Hi,

In our network, we have slowness issue traffic between the Primary Data center to the Azure cloud. only one-way traffic.

Server (in UCS cluster Vmware Esxi) - Fabric Switch - Nexus7K - Nexus9k - CEISR01 (MPLS router) - Express Route - End deice (in Azure Cloud).

End device (in Azure cloud)  to Server (in Datacenter UCS) is fast.

Server (in Datacenter UCS) to End device (in Azure cloud) is very slow. when we captured the packets that traffic we observed duplicate packets and retransmitting is pretty high.

Cisco Engineers said no issue in network devices (Nexus7k, 9K, CEISR01)

Vmware,Azure,MPLS provider, Express route also reply as it is not their issue.

is there any segment did I miss to check and may I know what could be the issue?

Appreciate your suggestion. 

Regards

Aung

[Kirk J]

Since you have already ID'd a possible cause (dup packets, retransmits), sounds like you are going to need to do a few more packet captures at different devices/interfaces to see at what point those problems are being introduced.  What is the equipment you manage before the packets are handed off to the ISP? MPLS router?

Kirk...

[alvinaung]

Thanks for the reply. yes, it is an MPLS router. could it be a routing issue? why i am asking is the last testing what i found is if the traffic go from DMZ VLAN is faster than other servers VLAN. In UCS they have different servers are setup. some are for internal Data and some for DMZ. Thanks again. 

[Kirk J]

In the UCSM hosting the HX server, you can configure a disjoint layer 2 config, where one setup of uplinks are carrying prod vlans, and another set are carrying DMZ.  Are you DMZ vlans/uplinks going to a different device than your prod vlans?

Kirk...