Troubleshooting Ethernet Errors

[TechTrend]

I converted an ESXi 6 physical host to Proxmox 4.4 for a test and moved two VMs (Linux 64-bit and FreeBSD 32-bit). Hardware is a SuperMicro X8DTE motherboard with dual X5650's, 72GB RAM and 6 Ethernet gigabit ports. The hypervisor and VMs seem to be working fine, but ethernet interfaces report RX/TX errors. This is an example on the first Ethernet port on the motherboard (eth0):

root@pve0:~# ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:1b:78:58:ff:ea
          inet6 addr: fe80::21b:78ff:fe58:ffea/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:325167 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2477 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:21373118 (20.3 MiB)  TX bytes:257992 (251.9 KiB)
          Interrupt:16 Memory:faae0000-fab00000

A Google search led to some posts suggesting disabling rxhash (ethtool -K eth0 rxhash off), but that doesn't seem to make a difference. What could be causing these errors? These are the PVE versions and interfaces (using Open vSwitch). eth0/vmlan0 is used for VM traffic, eth1/ilan0 and eth3/ilan1 are used for iSCSI traffic.

Thanks.

root@pve0:~# pveversion -v
proxmox-ve: 4.4-76 (running kernel: 4.4.35-1-pve)
pve-manager: 4.4-1 (running version: 4.4-1/eb2d6f1e)
pve-kernel-4.4.35-1-pve: 4.4.35-76
lvm2: 2.02.116-pve3
corosync-pve: 2.4.0-1
libqb0: 1.0-1
pve-cluster: 4.0-48
qemu-server: 4.0-101
pve-firmware: 1.1-10
libpve-common-perl: 4.0-83
libpve-access-control: 4.0-19
libpve-storage-perl: 4.0-70
pve-libspice-server1: 0.12.8-1
vncterm: 1.2-1
pve-docs: 4.4-1
pve-qemu-kvm: 2.7.0-9
pve-container: 1.0-88
pve-firewall: 2.0-33
pve-ha-manager: 1.0-38
ksm-control-daemon: 1.2-1
glusterfs-client: 3.5.2-2+deb8u3
lxc-pve: 2.0.6-2
lxcfs: 2.0.5-pve1
criu: 1.6.0-1
novnc-pve: 0.5-8
smartmontools: 6.5+svn4324-1~pve80
zfsutils: 0.6.5.8-pve13~bpo80
openvswitch-switch: 2.3.0+git20140819-3+deb8u1

root@pve0:~# cat /etc/network/interfaces
auto lo
iface lo inet loopback

allow-vmbr0 eth0
iface eth0 inet manual
        ovs_type OVSPort
        ovs_bridge vmbr0

allow-vmbr1 eth1
iface eth1 inet manual
        ovs_type OVSPort
        ovs_bridge vmbr1
        mtu 9000

iface eth2 inet manual

allow-vmbr3 eth3
iface eth3 inet manual
        ovs_type OVSPort
        ovs_bridge vmbr3
        mtu 9000

iface eth4 inet manual

iface eth5 inet manual

allow-ovs vmbr0
iface vmbr0 inet manual
        ovs_type OVSBridge
        ovs_ports eth0 vmlan0

allow-ovs vmbr1
iface vmbr1 inet manual
        ovs_type OVSBridge
        ovs_ports eth1 ilan0
        mtu 9000

allow-ovs vmbr3
iface vmbr3 inet manual
        ovs_type OVSBridge
        ovs_ports eth3 ilan1
        mtu 9000

allow-vmbr0 vmlan0
iface vmlan0 inet static
        ovs_type OVSIntPort
        ovs_bridge vmbr0
        ovs_extra set interface ${IFACE} external-ids:iface-id=$(hostname -s)-${IFACE}-vif
        address  192.168.1.210
        netmask  255.255.255.0
        gateway  192.168.1.1

allow-vmbr1 ilan0
iface ilan0 inet static
        ovs_type OVSIntPort
        ovs_bridge vmbr1
        ovs_extra set interface ${IFACE} external-ids:iface-id=$(hostname -s)-${IFACE}-vif
        address  10.254.1.210
        netmask  255.255.255.0
        mtu 9000

allow-vmbr3 ilan1
iface ilan1 inet static
        ovs_type OVSIntPort
        ovs_bridge vmbr3
        ovs_extra set interface ${IFACE} external-ids:iface-id=$(hostname -s)-${IFACE}-vif
        address  10.254.2.210
        netmask  255.255.255.0
        mtu 9000

 

[manu]

Hi
Did you post the right ifconfig output ?
I am not seeing errors in:
RX packets:325167 errors:0 dropped:0 overruns:0 frame:0
TX packets:2477 errors:0 dropped:0 overruns:0 carrier:0

IIRC you should not worry too much about these errors, since they can simply mean a wrong CRC in an incoming ethernet frame (ie it's perfectly normal to have this non-zero)
You should just worry if the count of this errors increase like every second.

 

[TechTrend]

Thanks for your response.

Apparently the errors went away after implementing the changes to a pfSense VM for Disable hardware checksum offload and others suggested on pfSense forums. Made several reboots and didn't notice 'ifconfig' stopped reporting errors at some point.

 

[manu]

Yes, this is a known issue in FreeBSD.
The corresponding bug report in FreeBSD is:
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=165059
but it hasn't seen a lot of activity lately.