We help IT Professionals succeed at work.

Jumbo ports on a Cisco catalyst 3750

Last Modified: 2012-06-21

I have a question to how specific ports can be configured using jumbo frames and leaving other ports with the default mtu 1500.
We have a 4 Switches stacked, 2*ws-c3750g-12s which are our backbone switches and have 48 port 10/100 switches connected to them.
The other 2 switches in the stack are  ws-c3750g-24t and these act server/storage devices connect to them. 4 ports on these switches we want to turn on Jumbo packets for the storage devices.(Netapps fas device) These 4 ports are in 1 vlan and the vlan is only on this stacked switch.  The switches and MTU setting is as below.
switch 1 provision ws-c3750g-12s
switch 2 provision ws-c3750g-12s
switch 3 provision ws-c3750g-24t
switch 4 provision ws-c3750g-24t
system mtu routing 1500
After looking through the above link I am led to believe that individual ports cannot be configured to accept Jumbo packets, as it is a sytem setting on the switch. Since all the ports in this stacked switch are gig ports this would mean all ports are configured for Jumbo packets ?
So the question is how does one change 4 spercific ports for jumbo packets and leave the other ports to receive packets of 1500.

The ports in question are
Interface portchannel11
Interface portchannel10
interface GigabitEthernet3/0/10
interface GigabitEthernet3/0/11
interface GigabitEthernet4/0/10
interface GigabitEthernet3/0/11

I would be gratefull for any help offered.

Watch Question

This one is on us!
(Get your first solution completely free - no credit card required)


Yeah I have just been googling and your solution sounds correct, we also just want to segregate the iSCSI traffic we are managing this with a seperste vlan for the iSCSI traffic, and the esx vm servers are in a seperate vlan on the same switch a very similar setup to yourself.

So going from the above, we just have to enable jumbo packets ont the switch.

3750(config)# system mtu jumbo 9000
3750(config)# exit
3750# reload
Then configure the netapps iSCSI trafic to send Jumbo packets.


Gain unlimited access to on-demand training courses with an Experts Exchange subscription.

Get Access
Why Experts Exchange?

Experts Exchange always has the answer, or at the least points me in the correct direction! It is like having another employee that is extremely experienced.

Jim Murphy
Programmer at Smart IT Solutions

When asked, what has been your best career decision?

Deciding to stick with EE.

Mohamed Asif
Technical Department Head

Being involved with EE helped me to grow personally and professionally.

Carl Webster
CTP, Sr Infrastructure Consultant
Empower Your Career
Did You Know?

We've partnered with two important charities to provide clean water and computer science education to those who need it most. READ MORE

Ask ANY Question

Connect with Certified Experts to gain insight and support on specific technology challenges including:

  • Troubleshooting
  • Research
  • Professional Opinions
Unlock the solution to this question.
Join our community and discover your potential

Experts Exchange is the only place where you can interact directly with leading experts in the technology field. Become a member today and access the collective knowledge of thousands of technology experts.

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.


Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.