Occasional Contributor
Frequent ContributorHave you looked into https://www.intel.com/content/www/us/en/programmable/documentation/xgz1560360700260.html#tne1573761134640
on setting/checking the MTU size?
Occasional ContributorThanks for your reply!
Actually we have checked the size of MTU of wrapper and modified it to 9600. The MTU of XL710 would be returned to the default value 1500 even though we set it to 9600 after bounding to vfio-pci driver in the mode of DPDK . But we could receive jumbo frames.
The problem is the card can not forward jumbo frames.
Using signal-tap we captured some signals and found that egr_out* signals are correct. Based on this, we can deduce XL710 and DPDK have no problem. So we think that there may exist some configurations in the path of egr_out* to QSFP, which limits the forwarding of jumbo frames.
In the other experiment, we connected the ing_in*----egr_out* directly, and the forwarding of jumbo frames failed too. I think this is further confirmation that our consideration is right. The bottleneck is between egr_out and QSFP, and that's exactly what corresponds to nfv_eth_wrapper, mux, demux and some other modules in RTL project.
Frequent ContributorI believe if you are in DPDK, you need to revert back to OPAE to set the MTU. See below link to revert back to OPAE.
Occasional ContributorThe matter is that if I revert back to OPAE and set the MTU size again, the MTU of XL710 would be returned to the default value 1500 even though we set it to 9600 after bounding to vfio-pci driver in the mode of DPDK
Occasional ContributorThank you for your continued attention.
We have found that some dpdk application can fully support giant frame and we ported the related functions to other applications. So far the issue with giant frame support has been resolved.
Frequent ContributorThank you for the update. Would you share with us what is the dpdk application and how you used it to support jumbo frames? I think it will be a good learning for all other forum users as well.
Occasional Contributorwell, It's my pleasure to help others.
1. DPDK L3fwd supports jumbo frames originally when you run it with '--enable-jumbo --max-pkt-len 9600 ';
2.the default mtu size of N3000-1(10G) is 1500, one should change it to 9600, and you can get the command by looking in the manual of ug-ias-n3000(chapter 8.1); the default mtu size of N3000-2(25G) is 9600, it have no need to be changed.
3. you can modify the mode of rx and tx to support jumbo frames by reference to l3fwd CMD_LINE_OPT_ENABLE_JUMBO_NUM module
For example, in the l2fwd application, you need to make the following changes
