MTU 9000 ping not working (VMWare/Server 2003)

RobertKaucherRobertKaucher Member Posts: 4,299 ■■■■■■■■■■
I have a VMware host attached to an iSCSI SAN. I'm attempting some performance testing and I am configuring the system to allow Jumbo Frames. I have created a virtual switch for the storage network and have the proper MTU configured on the VMware system (NICs/vSwitch) as well as on the physical switch and the storage server. There are two VMs where I am testing iSCSI performance. One is Server 2008 R2 one is Server 2003 R2 (x86) I can perform pings with 9000 bytes to and from the ESXi host and storage server. I can Perform pings of 9000 bytes to and from the Server 2008 R2 VM and the storage server/ESXi host.

I am unable to ping using anything over 1500 bytes on the Server 2003 R2 system. I have checked everything I can imagine and cannot think of what might be causing the problem. I used DrTCP to configure the MTU on the VM, ensured that the NIC is VMXNET 3 and Jumbo Frames is enabled on the NIC. It is connected to the storage network.

Any ideas?

Comments

  • MentholMooseMentholMoose Member Posts: 1,525 ■■■■■■■■□□
    Check the Advanced tab on the vmxnet3 driver properties in Device Manager. There is an option for jumbo frames.
    MentholMoose
    MCSA 2003, LFCS, LFCE (expired), VCP6-DCV
  • RobertKaucherRobertKaucher Member Posts: 4,299 ■■■■■■■■■■
    Already done. It was one of the first things I checked as this was my second time configuring it on a VM.
  • MentholMooseMentholMoose Member Posts: 1,525 ■■■■■■■■□□
    Are you only using one vSwitch for all the VMs? If not, make sure to enable jumbo frames on every vSwitch.
    MentholMoose
    MCSA 2003, LFCS, LFCE (expired), VCP6-DCV
  • RobertKaucherRobertKaucher Member Posts: 4,299 ■■■■■■■■■■
    1 vSwitch dedicated to the storage network. 2 teamed NICs.
    Switch Name    Num Ports   Used Ports  Configured Ports  MTU     Uplinks
    vSwitch1       64          6           64                9000    vmnic2,vmnic3
      PortGroup Name      VLAN ID  Used Ports  Uplinks
      Storage Network     0        1           vmnic2,vmnic3
      VM Storage Network  0        2           vmnic2,vmnic3
    
    ~ # esxcfg-vmknic -l
    Interface  Port Group/DVPort   IP Family IP Address                              Netmask         Broadcast       MAC Address       MTU     TSO MSS   Enabled Type
    vmk0       Management Network  IPv4      10.1.46.194                             255.255.255.0   10.1.46.255     00:22:19:24:14:a9 1500    65535     true    STATIC
    vmk1       Storage Network     IPv4      172.16.1.3                              255.255.255.0   172.16.1.255    00:50:56:7c:8d:ba 9000    65535     true    STATIC
    
  • MentholMooseMentholMoose Member Posts: 1,525 ■■■■■■■■□□
    Try adding another NIC to the 2003 machine besides a vmxnet3. Maybe it's a driver problem with vmxnet3 on 2003 32-bit.
    MentholMoose
    MCSA 2003, LFCS, LFCE (expired), VCP6-DCV
  • RobertKaucherRobertKaucher Member Posts: 4,299 ■■■■■■■■■■
    I just tried the VMXNET 2 (Enhanced), disabled the original NIC, and it did not work either. Really we will only be using Server 2008 R2 systems, so it may not matter. But I do not like not being able to give an answer to a question I may be asked.

    EDIT: I've given up on this, so don't anyone stress about figuring it out. If I find an answer I will post back.
  • MentholMooseMentholMoose Member Posts: 1,525 ■■■■■■■■□□
    Yeah that is annoying. Unfortunately I don't have any other suggestions right now. Hopefully someone else can help.
    MentholMoose
    MCSA 2003, LFCS, LFCE (expired), VCP6-DCV
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