What is “socket SO_UDPCHECKSUM option setting failed error” in Cisco Catalyst 6500 Series Switch?

While checking the daily logs in one our Cisco Catalyst 6500 Series Switch I figured out following error “socket SO_UDPCHECKSUM option setting failed error”. For the past five years this Cisco Catalyst Switch worked well without any problems, the sudden emergence of this error “socket SO_UDPCHECKSUM option setting failed error” forced me to think what were the last modifications? I figured out the last thing what we did was configurations of few IP SLA’s. When I checked Cisco web site it was confirmed the error was generated due to the configuration of IP SLA. We are currently using the IOS Version 12.2(33) SXH8b. This IOS version has a bug.

According to Cisco Systems the error “socket SO_UDPCHECKSUM option setting failed error” has no negative impact on the Cisco Catalyst 6500 series Switch. The work around is to remove IP SLA configuration or upgrade the IOS version.

This error appeared for the first time in the IOS version 12.2(33)SXI1 and this bug is fixed in following IOS versions

12.2(32.8.11)SX291
12.2(32.8.11)XJC273.11
12.2(33.2.4)SXI
12.2(32.8.1)YCA273.15
12.2(33)SXI3
12.2(32.8.15)YCA273.10
12.2(33)SXI4
15.0(1)SY

So if you happen to see the following error in your Cisco Catalyst 6500 Series switch don’t panic, the bug has least impact on device the only work around is either to remove the IP SLA or to upgrade the IOS of the device.