Intel Ethernet X520 10GbE Dual Port KX4 Mezz User Manual page 88

Multiple Interfaces on Same Ethernet Broadcast Network
Due to the default ARP behavior on Linux, it is not possible to have one system on two IP networks in the same Eth-
ernet broadcast domain (non-partitioned switch) behave as expected. All Ethernet interfaces will respond to IP traffic for
any IP address assigned to the system. This results in unbalanced receive traffic.
If you have multiple interfaces in a server, turn on ARP filtering by entering:
echo 1 > /proc/sys/net/ipv4/conf/all/arp_filter
(this only works if your kernel's version is higher than 2.4.5).
NOTE: This setting is not saved across reboots. However this configuration change can be made permanent
through one of the following methods:
Add the following line to /etc/sysctl.conf:
l
net.ipv4.conf.all.arp_filter = 1
Install the interfaces in separate broadcast domains (either in different switches or in a switch partitioned
l
to VLANs).
Do Not Use LRO when Routing Packets
Due to a known general compatibility issue with LRO and routing, do not use LRO when routing packets.
MSI-X Issues with Kernels Between 2.6.19 and 2.6.21 (inclusive)
Kernel panics and instability may be observed on any MSI-X hardware if you use irqbalance with kernels between
2.6.19 and 2.6.21. If these types of problems are encountered, you may disable the irqbalance daemon or upgrade to a
newer kernel.
Rx Page Allocation Errors
Page allocation failure order:0 errors may occur under stress with kernels 2.6.25 and above. This is caused by the way
the Linux kernel reports this stressed condition.
Unloading Physical Function (PF) Driver Causes System Reboots when VM is Run-
ning and VF is Loaded on the VM
Do not unload the PF driver (igb) while VFs are assigned to guests.
Host May Reboot after Removing PF when VF is Active in Guest
Using kernel versions earlier than 3.2, do not unload the PF driver with active VFs. Doing this will cause your VFs to
stop working until you reload the PF driver and may cause a spontaneous reboot of your system.
ixgbe Linux* Driver for the Intel® 10 Gigabit Server Adapters
ixgbe Overview
WARNING: By default, the ixgbe driver complies with the Large Receive Offload (LRO) feature enabled. This
option offers the lowest CPU utilization for receives but is incompatible with routing/ip forwarding and bridging. If
enabling ip forwarding or bridging is a requirement, it is necessary to disable LRO using compile time options as
noted in the LRO section later in this section. The result of not disabling LRO when combined with ip forwarding
or bridging can be low throughput or even a kernel panic.
This file describes the Linux* Base Driver for the 10 Gigabit Intel® Network Connections. This driver supports the 2.6.x
kernels and includes support for any Linux supported system, including X86_64, i686 and PPC.
This driver is only supported as a loadable module. Intel is not supplying patches against the kernel source to allow for
static linking of the driver. A version of the driver may already be included by your distribution or the kernel. For ques-
tions related to hardware requirements, refer to
with Linux.
System Requirements. All hardware requirements listed apply to use