What is LRO in VMware?

What is LRO in VMware?

Large Receive Offload (LRO) is a technique to reduce the CPU time for processing TCP packets that arrive from the network at a high rate. LRO reassembles incoming packets into larger ones (but fewer packets) to deliver them to the network stack of the system.

What is LRO and TSO?

Enable TCP Segmentation Offload (TSO) and Large Receive Offload (LRO) can improve FortiGate-VM performance by reducing the CPU overhead for TCP/IP network operations. TSO causes network cards to divide larger data chunks into TCP segments.

What is LRO network?

Large Receive Offload (LRO), or Receive Side Coalescing (RSC), allows a network interface controller to combine incoming TCP/IP packets that belong to the same connection into one large receive segment before passing it to the operating system. LRO is available on some new network interface controllers.

How do I disable LRO?

To enable or disable LRO for the default TCP/IP stack on the host, that is, for VMkernel adapters:

1. In the vSphere Web Client, on the Manage tab for the host, click Advanced System Settings and set Net.
2. In an ESX/ESXi Shell on the host, set the /Net/TcipDefLROEnabled to 1 to enable LRO or to 0 to disable it.

What is TSO in Linux?

TCP Segmentation Offload is supported in Linux by the network device layer. A driver that wants to offer TSO needs to set the NETIF_F_TSO bit in the network device structure. In order for a device to support TSO, it needs to also support Net:TCP checksum offloading and Net:Scatter Gather.

What is GRO in Linux?

Generic Receive Offload (GRO) is a software technique in Linux to aggregate multiple incoming packets belonging to the same stream. The linked article claims that CPU utilization is reduced because, instead of each packet traversing the network stack individually, a single aggregated packet traverses the network stack.

What is UDP Gro?

UDP GRO performs a socket lookup for each ingress packets and aggregate datagram directed to UDP GRO enabled sockets with constant l4 tuple. UDP GRO packets can land on non GRO-enabled sockets, e.g. due to iptables NAT rules, and that could potentially confuse existing applications.

How do I disable TSO in Linux?

Examples

1. To enable TSO for a network device eth0 issue: # ethtool -K eth0 tx on sg on tso on.
2. To disable TSO for a network device eth0 issue: # ethtool -K eth0 tx off sg off tso off.