Avi Service engine crashes when L3 DSR is enabled
Article ID: 399127
Updated On:
Products
Issue/Introduction
The Service Engine can crash when L3 DSR is enabled with TSO.
In such a scenario, Service Engine can crash with a segmentation fault at rte_atomic16_add_return
To investigate further, you can review the latest stack traces from the Controller or SE by accessing the following path:
CLI:
Log in to the Controller via SSH and run this command. Please note you have to replace the name of se_dp file here.
root@<Controller ip>:# cat /opt/avi/archive/stack_traces/<se_dp.timestamp>.stack_trace
UI:
Navigate to Administration > Support > Crash Reports > Expand the latest crash file.
Environment
Affected Version: 22.1.6
Cause
The root cause of the issue was identified as an attempt to utilize TCP Segmentation Offload (TSO) with Layer 3 Direct Server Return (L3-DSR) on the Avi platform, a configuration that is not supported.
Consequently, the setting of TSO flags on these packets led to the corruption of the IP-in-IP encapsulated traffic, manifesting as the observed problem.
Resolution
The workaround is to disable TSO and LRO for the service engine group.
Please refer to the commands below.
Login to controller CLI
shell
configure serviceenginegroup <se_group_name>
disable_tso
no se_lro
saveNote: The reboot of service engines is mandatory for changes to take effect.
Additional Information
The issue has been fixed in 22.1.7
Please refer to the below KB for further details.
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