Collisions on network interface re0

VPS users may notice collisions on their network interface re0 and re1, for example:


Name    Mtu Network       Address              Ipkts Ierrs Idrop    Opkts Oerrs  Coll
re0 1500 00:16:3e:d8:bc:a9 74835699 0 0 71409776 0 65006478


The reason for this is that the Realtek NIC driver in FreeBSD expects the Realtek NIC to do hardware checksum offloading.  This feature is not implemented in the virtual NIC that our Xen platform uses.  So, the reported checksums are due to a mismatch between the FreeBSD driver and the fake hardware, but do not indicate a true networking problem.

You can disable checksum offloading in FreeBSD by adding these two options to the ifconfig_re0 and ifconfig_re1 lines.  Depending on when your VPS was setup, these may be configured either in /etc/rc.conf or /etc/rc.conf.local.  The two options are "-rxcsum" and "-txcsum".

Example configuration with these options:

ifconfig_re0="inet netmask -rxcsum -txcsum"
ifconfig_re1="inet netmask -rxcsum -txcsum"


If you have any questions, please feel free to contact our support department and we'll be glad to assist you with this change.

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