guests cannot tftp on esxi 4

[jimbartus]

For some reason TFTP and so far just TFTP is failing on all guests on esxi 4 for me. I have it installed on a Dell SC1435 and a Dell M610, both with very simple single-interface default networking configs.

When I boot up a new VM it dhcp's and gets its IP fine, but it times out at the tftp stage (my dhcp server is handing out the next-server and filename fields as part of a cobbler setup).

Here's some things I've tried to narrow it down.

• using a separate M610 in the same blade chassis on the same network I can PXE boot a centos 5.3 install without issue

• running centos 5.3 on that blade I can then use the cli tftp client to fetch the /pxelinux.0 file no probem.

• tcpdumping on the tftp server it never sees the request (when it comes from a guest)

• uploading a centos ISO to the datastore on the esxi server and building the vm from there works. That vm can then be ssh'd into, and can run yum update, but it cannot tftp (dns works too)

• running a tftp server on the guest vm no other hosts can tftp fetch a file from it, so its both tftp in and tftp out failing

So whether its the bios/pxe-boot tftp client or the centos 5.3 tftp client neither work when the host is a guest on an esxi 4 server. However both work on the same hardware via the same network config if the physical host is running centos instead.

[RenaudL]

This is strange...

What about running both the tftp client & server in 2 VMs on the same host/vSwitch?

[jimbartus]

Good idea. I installed a second vm using and .iso on the datastore and setup a tftp server on it. Neither of the vm's can tftp to or from each other. Both can tftp from themselves via loopback. iptables and selinux are disabled completely.

[jimbartus]

Interesting new twist.

I have been using the e1000 interface that the create-new-vm wizard choses by default. I just tried changing one of the VMs over to a vmxnet3 interface. After installing vmware tools and rebooting the host can tftp as both a client and a server to other hosts that are not esxi4-guests with the e1000 driver.

So problem solved right? Just use vmxnet3.

Nope. It still does not work when trying to pxe boot. The bios screen clearly says "Network boot from VMware VMXNET3" and DHCP's just fine, but the tftp times out again.

[RenaudL]

Thanks for performing these experiments, that's exactly what I would have suggested.

Just to summarize, can you confirm this is what you're noticing?

- With e1000, neither pxe-tftp nor a Linux tftp client/server can communicate.

- With vmxnet3, pxe-tfp doesn't work but a tftp client/server can.

[jimbartus]

Exactly, yes.

[EDV-COMPAS]

hi folks,

i have seen some similar things on an SLES9 guest os, with installed vmware tools, there are some network services that no longer work correctly (scp) ...

without vmware-tools, everything is fine.

i have already seen this behavior before on some firewalls/vpns/routers ,and it was always some mtu problems ..

If you find this information useful, please award points for "correct" or "helpful".

[jimbartus]

RenaudL have you (or anyone else) been able to reproduce this? Is there a bug tracker I can file to or track this at?

[RenaudL]

RenaudL have you (or anyone else) been able to reproduce this? Is there a bug tracker I can file to or track this at?

I'm pretty busy with other issues at the moment, but be assured that this is in my queue.

[jimbartus]

some more details, a freshly created guest with vmxnet2 (enhanced) chosen as the adaptor type fails both pxe-tftp and client/server tftp from the guest os. so to update your bulletpoints:

- With e1000 or vmxnet2(e), neither pxe-tftp nor a Linux tftp client/server can communicate.

- With vmxnet3, pxe-tfp doesn't work but a tftp client/server can.

[jordan_lederman]

Please post both your physical uplink config and your virtual switch config.

[swhtng]

Hi,

Is there any update on this? I'm setting up a guest on ESXi 4 and trying to make them TFTP from an Altiris server, unsuccessfully. With VMWare Server 2 it works if I set the network card to E1000, but it still doesn't work with ESXi.

Thanks,

Erik

[swhtng]

Ok, this was a pebkac. The support guy put the server onto a different network which was unable to reach the TFTP server...

It works with both E1000 and VMNET 3 cards.

[marzlarz]

Was there ever a resolution to this issue? I am experiencing the same issues on ESXi 5.0.0

I am currently working with VMWare Support, but we have not found a solution yet. If anyone has one, that would be greatly appreciated.

Here are the finding from my troubleshooting:

ESXi 4.1.0 ( All Standard vSwitches using vmxnet3 )

VM -> VM TFTP Server  Works just fine

ESXi 5.0.0 ( All Distributed vSwitches using vmxnet3 )

VM -> VM TFTP Server Does not work

VM -> Physical TFTP server  Does not work

Physical -> VM TFTP server  Does not work

Physical -> Physical TFTP Server Works just fine

Any help would be greatly appreciated.

Thanks!

[mattinde]

Has anybody gotten this resolved. In an ESXi 5.0.1 environment we are running into the same problem. Everything worked fine on standard switches in 4.1 and on standard switches in 5.0.0 and 5.0.1 - but as soon as I migrated these VMs to distributed virtual switches, TFTP on them stopped working. Putting a support call in now, but was curious if anybody else had gotten this resolved somehow.

Turns out it wasn't working on standard switches, but was working with E1000 network cards. When I replaced the vmxnet3 adapters with E1000 adapters on this Linux VM, TFTP started working again. Based on some other issues we have had with Linux VMs and vmxnet3 adapters, I am beginning to think they don't play as well together as they should (even with uninstalling/reinstalling VMware Tools with each system update).