6100 recommended setting "network interfaces" and tunables

ddbnj

I had to disable hardware TCP segmentation offload, hardware large receive offload, and enabled the ALTQ support for hn NICs on my last piece of hardware.

Does anyone know the recommended settings for the 6100?

Thanks,

Devan

ddbnj

@ddbnj

Well, I unchecked everything and it seems to be working.

stephenw10

The default setting there should work fine. That is TSO and LRO disabled and Checksum offload enabled.
You should only need AltQ enabled for hn NICs if you're running in Hyper-V or Azure.

Steve

AngryAnt

@stephenw10 Is this still the recommendation today? To confirm, as I read your reply here:

For the 6100 the following performance settings in "System / Advanced / Networking" are recommended:

Hardware checksum offload: Enabled.
- Meaning the "Disable hardware checksum offload" checkbox is not ticked.
Hardware TCP Segmentation Offloading (TSO, TSO4, TSO6): Disabled.
- Meaning the "Disable hardware TCP segmentation offload" checkbox is ticked.
Hardware Large Receive Offloading (LRO): Disabled.
- Meaning the "Disable hardware large receive offload" checkbox is ticked.
hm ALTQ support: Disabled.
- Meaning the "Enable the ALTQ support for hn NICs." checkbox is not ticked.

Diverging from these settings will lead to worse performance. If throughput issues are experienced, diverging from these settings will not resolve this.

Is that correctly understood?

stephenw10

LRO and TSO should work fine with the NICs in the 6100. But they are disabled by default so far less tested. If there is a bug there it may not have been discovered because the vast majority of users are not running that. So for stability I would leave them disabled. Also the performance benefits they bring to a router is pretty minimal.

Steve