When configuring an iSCSI network, don’t forget to enable the Jumbo Frames on you physical switches. Follow these steps to enable the Jumbo Frames on a specific VLAN on a HP ProCurve switch:
- Login to your switch.
- After login type: <switch># config
- You will enter the config mode, type: <switch>(config)# show vlans to show the VLAN configuration.
- To enable Jumbo Frames on the VLAN type: <switch>(config)# vlan <ID#> jumbo
- Check if the setting applied successfully by typing: <switch>(config)# show vlans again. The Jumbo column for the specific VLAN in the output should change to Yes.
- Save your changes:<switch>(config)# write memory
- Logout from the switch.
Tested on a HP ProCurve 2900-24G switch.
Thanks for your notes for configuring Jumbo Frames
This also worked on an HP Procurve 5406zl switch
Are there any consequences to enabling jumbo frames on procurve 2510g-48 switches? COuld this cause issues on my network etc??
Well, it depends. Jumbo frames are usually used in storage networks. It’s is not recommended to mix the regular network traffic with storage traffic.
There can always be consequences 🙂 jumbo packets save CPU time on your devices and are a little more efficient on network bandwidth due to the reduced header information. You fit up to 6 times more data (on a standard jumbo packet) vs a regular packet. The down side is that your networking equipment (to your border ideally) should support jumbo packets.
As Marek said, jumbo packets are generally used on iSCSI SAN networks to reduce the processing overhead given the high volume of packets that flow across those networks, however, you can give your production network a slight performance improvement if your equipment (and network cards) support it. Generally it’s not enough to worry about for your normal network environment though.
Thanks for this Marek, it helped resolve a storage issue we had on our E3800-24. The default VLAN indicates Jumbo frames are on when in fact the MTU is correct but Jumbo Franmes was actually disabled. I used your post show this and change the MTU on the storage VLAN. Awesome!
Thanks.. It worked for me.. 🙂
Can you do this to a live environment without causing issues to iscsi connections?
If I recall correctly, yes. But there could be changes in the new software since this is quite old blog. I suggest you consult the manual or ask your HP representative.
Thanks for the quick reply. We have two running in a cloud environment and we’re migrating off the current SAN and need to make changes to config but can’t find anything in the manual. I don’t want to break any VMs in the process. Will see if I can get anything from tech support.
No problem Nigel,
Just one thing I forgot to mention. When you migrate to jumbo frames make sure you configure the whole stack for JFs otherwise you can get some performance issues. I suggest you enable JFs on non-production hours and test the performance.
is jumbo frame enable by default ?
No, Jumbo frames are disabled by default.
Why jumbo command is not accepted on a procurve 2650 J4899A…Is there a other commando what do the same?
I have no idea. Is your firmware up to date?
Is there will be a problem if the hp procurve 2920 10/100/1000 is set in a jumbo frame and the other switches is hp procurve 2520 10/100 is set in jumbo frame?
It depends. If you configure for example iSCSI traffic for your ESXi hosts then you have to configure the whole stack to use jumbo frames. In some switch types you can set it up for the VLAN only.
Hope this helps.
Can any one confirm if jumbo frame can be set on only one VLAN (not the whole switch) on HP ProCurve 2510g-48 switch?
You can test this when you are in the vlan config mode. If there is a command to enable jumbo frames there, you should be able to set the jumbo frames per vlan. Otherwise this will be a global switch command if I am not mistaken.
Hope this helps.
Good stuff Marek,
I just tested on ProCurve Switch 2510G-48 (J9280A) and I was able to set jumbo frame on one VLAN only. Thank you for your help! ( Dziekuje 🙂 )
Thanks for sharing! 🙂
If I set all of my ports to Jumbo frames, do regular frames pass through as normal? I have 3 48-port HP2810 + 1 24-port HP2810 stacked. I can definitely see setting the iSCSI vLAN to Jumbo, but what about the rest of the network? If I set all ports to support jumbo what happens to all the hardware?
It’s really weird. I had a power failure recently, and I think it disabled Jumbo’s on my 48 port that I have my VMWare ESXi and EMC San attached to. I also had a Mac xserve in the same iSCSI vlan. When power came back I couldn’t get my Mac to connect to the iSCSI drives I had setup. Spent about 4 days trying to solve the problem. I changed the MTU in my Mac xserve to 1500 and bam, all 4 drives finally popped up on the Mac. My EMC and VMWare was running fine, both are set to Jumbo (9000). The switch however, has Jumbo disabled on all ports/vlans. Why is my VMWare still working at 9000?
The whole thing is confusing the heck out of me now. It totally stumped the support company that tried to help me resolve the problem. 4 days to find one setting. Everything worked fine for 2-3 years prior to this power failure. I’m beginning to doubt the settings ever were jumbo in the switch, but it had to be the problem. The SAN is still set to 9000. The switch between them is set to 1500 still. How is the SAN talking to the Mac, which is set to 1500.
thank you. Time saver.
My pleasure Paul! 🙂
Can I set mtu less than 1400 on HP 3500
Probably not. Why would you want to do this? Standard ethernet frame is 1500 MTU.
I’ve enabled the jumbo on one of my vlans (thanks it was a massive time saver). However its saying enabled in Telnet but its not enabled on the WebUI any ideas?
I’m using the HP-2920-48G.
Hi Chris, difficult to say. Is your firmware up to date?
This is great information. My HP 2920 shows “Giants Rx” errors on two ports. Since I have to set jumbo frames at the VLAN level I must determine the VLAN that incurred these errors. How do I do this? There are multiple VLANs on these two ports.
UPDATE for my above question: Looks like it may not matter. According to this Experts Exchange thread (https://www.experts-exchange.com/questions/27863230/how-do-I-enable-jumbo-frames-on-a-HP-Procurve-2824-switch.html – it is paid content so I won’t post it directly), if you enable JF on a VLAN, then all ports affected by your setting can also receive JF on any VLAN assigned to that port. Therefore I don’t HAVE to know which VLAN caused the “Giants Rx” errors really. I already know which PORTS had the errors so I am just going to pick a VLAN (the one I believe is most likely) and enable JF on it. There will be a side effect of a few other ports being enabled for JF, I realize.
If there was a way to narrow down my “Giants Rx” errors to a particular VLAN that would be ideal, so I suppose my initial question is still valid.
Thx. But whats the command to disable jumbo again?
I think it was: no vlan VLAN_ID jumbo
Can jumbo be enabled on ap connected ports or vlans. Can anyone suggest