Guv
Enthusiast
Enthusiast

Changing MTU value on vmnic

I am running esx 4.1 servers, and am in process of enabling jumbo frames for the esx servers. I know the value of mtu as to be changed from 1500 to 9000. I think i now the command to change the mtu value of the vswitch which is :

esxcfg-vswitch -m 9000 vSwitch

The problem is changing the mtu value of vmnic on this vswitch. I currently on this vswitch have a vmkernal port group called vmkernal1 which has an IP setting of 172.16.10.1. Currently this has the value of mtu of 1500. But I need to change this to 9000. From reading other posts it says i have to recreate the vmkernel port group to change the mtu value. Is this correct one esx 4.1. So if i use the below command to change my existing vmnic's mtu value :

esxcfg-vmknic -a -i 172.16.0.1 -n 255.255.255.0 -m 9000 vmkernel1

Would this work. Or do I need to recreate, which would mean i would need to delete my existing port group first.

Can anyone advise, and exactly what command I need to run to change the vmnic mtu values, given the above parameters.

1 Reply
f10
Expert
Expert

I could enable Jumbo Frames using the -m option on an existing VMkernel portgroup. I have a Test VMkernel portgroup created with IP and Netmask assigned and MTU 1500

  1. esxcfg-vmknic -l

Interface Port Group/DVPort IP Family IP Address Netmask Broadcast MAC Address MTU TSO MSS Enabled Type

vmk2 Test IPv4 10.112.XX.XX 255.XX.XX.0 10.112.XX.XXX 00:50:XX:XX:XX:XX 1500 65535 true STATIC

I have changed the MTU size

~ # esxcfg-vmknic -m 9000 Test

Notifying the DCUI of configuration change

Interface Port Group/DVPort IP Family IP Address Netmask Broadcast MAC Address MTU TSO MSS Enabled Type

vmk2 Test IPv4 10.112.XX.XX 255.XX.XX.0 10.112.XX.XXX 00:50:XX:XX:XX:XX 9000 65535 true STATIC

Hope this helps Smiley Happy

If you found this or other information useful, please consider awarding points for "Correct" or "Helpful".

f-10

VCP3, VCP4, HPCP, HP UX CSA

Regards, Arun Pandey VCP 3,4,5 | VCAP-DCA | NCDA | HPUX-CSA | http://highoncloud.blogspot.in/ If you found this or other information useful, please consider awarding points for "Correct" or "Helpful".