kernel: xen_netfront: GSO size must not be zero


Oracle VM Server 3.3.1

Host: hostbase0
VM:   hostvm0

User cannot access from outside cluster via ssh.
ssh will hang here:


from ifconfig output, I can see a lot of err/invalid packages:

from sys log:  can see a lot of err mesg on xen_netfront.


It’s an oracle bug which marked in Metalink ID:1929676.1

Upgrade Linux kernel on Host to latest:

current kernel: kernel-uek-3.8.13-26.4.2.el6uek.x86_64

bond0: received packets cannot be forwarded while LRO is enabled


Oracle ODA Appliance, which based on ORACLE VM Server set.

Dom0/Host:  odahost1
Dom1/VM:    odahostdb1


use can not ssh onto Dom1/VM from outside ODA. ping is ok.

SSH will hang here:


From Dom0  /var/log/message:

This problem is due to LRO of eth0 not disabled.
Although bond0 LRO is disabled by default, eth0 which bond0 is based on is not.

just disable LRO on eth0

restart network service.


To make the changes permenant:

If Dom0/Host is EL5:
add following line to /etc/rc.local

If Dom0/Host is EL6+:
add following line to ifcfg-eth0:

the problem on EL5/6 different fix is on initscripts package version.

EL6 with initscripts 9.03+ accepts this ETHTOOL_OPTS, but EL5 with initscripts 8.45 does not.



Xen LRO is not disabled automatically with a bonded bridged interface with Intel X5xx 10 Gb Ethernet Adapter

Poor TCP Performance on VMs; dmesg:”received packets cannot be forwarded while LRO is enabled”