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+ dhcp_snoop process crashes due to memory leak + The following output is displayed in syslog once the process has crashed: ========================================== 'show logging log' 2020 Mar 31 04:15:33.393 [hostname] %SISF-3-INTERNAL: Internal error, Cannot allocate packet 2020 Mar 31 04:15:37.945 [hostname] last message repeated 26 times 2020 Mar 31 04:15:38.314 [hostname] %SISF-3-INTERNAL: Internal error, Cannot allocate packet 2020 Mar 31 04:15:53.411 [hostname] last message repeated 104 times 2020 Mar 31 04:15:53.958 [hostname] %SISF-3-INTERNAL: Internal error, Cannot allocate packet 2020 Mar 31 04:16:15.972 [hostname] last message repeated 138 times 2020 Mar 31 04:16:16.563 [hostname] %SISF-3-INTERNAL: Internal error, Cannot allocate packet ========================================== + The crash may eventually result in a core of the process ========================================== 'show cores' VDC Module Instance Process-name PID Date(Year-Month-Day Time) --- ------ -------- --------------- -------- ------------------------- 1 28 1 dhcp_snoop 32191 2020-04-08 06:32:02 ==========================================
+ Nexus 9K running software version 7.0(3)I7(6) + Receiving high amounts of IPv6 neighbor solicitation/neighbor advertisement traffic ========================================== 'ethanalyzer local interface inband display-filter "icmpv6.type == 136"' Capturing on inband 2020-05-11 12:51:27.472102 fe80::225:b5ff:fe10:30 -> fe80::12 ICMPv6 Neighbor advertisement 2020-05-11 12:51:27.472571 fe80::225:b5ff:fe10:30 -> fe80::12 ICMPv6 Neighbor advertisement 2020-05-11 12:51:27.473563 fe80::225:b5ff:fe10:30 -> fe80::12 ICMPv6 Neighbor advertisement 2020-05-11 12:51:27.474606 fe80::225:b5ff:fe10:30 -> fe80::12 ICMPv6 Neighbor advertisement 2020-05-11 12:51:27.475076 fe80::225:b5ff:fe10:30 -> fe80::12 ICMPv6 Neighbor advertisement 2020-05-11 12:51:27.476067 fe80::225:b5ff:fe10:30 -> fe80::12 ICMPv6 Neighbor advertisement 2020-05-11 12:51:27.477058 fe80::225:b5ff:fe10:30 -> fe80::12 ICMPv6 Neighbor advertisement 2020-05-11 12:51:27.478050 fe80::225:b5ff:fe10:30 -> fe80::12 ICMPv6 Neighbor advertisement 2020-05-11 12:51:27.478570 fe80::225:b5ff:fe10:30 -> fe80::12 ICMPv6 Neighbor advertisement 2020-05-11 12:51:27.480083 fe80::225:b5ff:fe10:30 -> fe80::12 ICMPv6 Neighbor advertisement ========================================== + While the issue is occuring you will slowly see the memory consumed by the 'dhcp_snoop' process increment until the "MemUsed" hits the "MemLimit". At which point you will see the symptoms above. ========================================== 'show processes mem | i snoop|Process|--' PID MemAlloc MemLimit MemUsed StackBase/Ptr Process ----- -------- ---------- ---------- ----------------- ---------------- 30264 54337536 1750758374 1044357120 ffafb810/ffaf905c dhcp_snoop ==========================================
+ Issue may resolve itself by automatically restarting the dhcp_snoop process + If not, you can perform one of the following: 1. Supervisor switchover 2. Restart the dhcp_snoop process manually via the bash shell 3. Reload switch
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