Contributor
Contributor

vds: No ping between VMs in different ESXi hosts

Hi

I have setup distributed switch in 5.1, I have all the VMs upgraded to version 9 (5.1 compatibilty) , while every ESXi has only one physNIC. I have migrated succesfully the management vmk0 to the distributed switch, but the strange thing is that there is no ping between VMs in different hosts. So practically the distributed switch is not working. As you can find below, the summary says that everything is up , there are no VLANs.

As you can see below, VM pfSense148 is in the same port group with vyatta VM, but on different hosts. Each of the different hosts is linked with uplink 1 and uplink 2 respectively. However , I cannot ping between those 2 VMs.

Please any ideas? Could you help?

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8 Replies
Expert
Expert

Hi, if your ESXi contains only one uplink, so should your Distributed Switch. From what I see you have two ESXi hosts plugged to different uplinks on the dVswitch - try moving both ESXi hosts NICs to Uplink 1 and see if your networking works as it should.

Stop by my blog if you'd like 🙂 I dabble in vSphere troubleshooting, PowerCLI scripting and NetApp storage - and I share my journeys at http://vmxp.wordpress.com/
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Contributor
Contributor

I have moved to the same uplink as you can see in the following figure but still no luck. In both VMs, network adapter 1 is matching the vds distributed port group, there are no VLANs and each one is having an IP on the same subnet (192.168.44.0/24). So I was expecting distributed switching to work. When I am deploying the same things but the hosts are in the same ESXi, ping works. With the same settings, if the two VMs are on different hosts, ping does not work.

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Expert
Expert

This shouldn't happen - how are these two ESXi hosts interconnected? Can you login via SSH to one ESXi host and ping the second one? What about traceroute from the first VM to the second one?

Stop by my blog if you'd like 🙂 I dabble in vSphere troubleshooting, PowerCLI scripting and NetApp storage - and I share my journeys at http://vmxp.wordpress.com/
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Contributor
Contributor

They are part of the same broadcast domain, in wireshark I can see that when I try to ping from one to the other, there is an ARP packet broadcasting but there is no answer. So as far as I can understand, I am not expecting traceroute to work, as I do not have next hops and different networks.

For the same thing, when I use VMs on the same ESXi host, arp request is getting a response with the MAC address of the target , so it works normally.

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Expert
Expert

This might be a bit silly but I noticed there are no VMware tools installed on pfSense machine. Can you install the tools and try that again? I'm quite baffled by this issue, if there isn't any firewall or physical network switching issue it should work out of the box :smileyshocked:

Stop by my blog if you'd like 🙂 I dabble in vSphere troubleshooting, PowerCLI scripting and NetApp storage - and I share my journeys at http://vmxp.wordpress.com/
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Enthusiast
Enthusiast

In know this is an old post, but did you ever find a solution? I'm experiencing the same problem with vSphere 6.7. 2 VM's cannot ping each other when on 2 different hosts wihtin a vDS. When on the same host they can ping. Also, these 2 VM's are not using a VLAN and also behind a Pfsense Firewall in a local network.

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Immortal
Immortal

Then you have an external switching issue in your network. Not related to a vDS configuration.

Contributor
Contributor

Had this issue - found that there was a duplicate VLAN on the dvswitch.   Hope it helps someone.

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