Hey guys!
I hope you can help me.
We are updating some switches, Catalyst 9200 and 9300, to the software release 17.6.4. (DNA and Network Essential).
Everything works as expected but we are getting some curious syslog warning messages.
%SISF-4-ENTRY_BLOCKED: Entry blocked Could not create the entry! no space left and not possible to free space
I found this explanation by cisco
%SISF-4-ENTRY_BLOCKED : Entry blocked [chars]
Explanation: An attempt to install an entry in the IPv6 binding table was blocked. This can be due to a conflicting entry or maximum number of entries reached
Recommended Action: If the maximum table size is reached, consider increasing it. If a conflicting entry already exist, this maybe an attempt to steal address ownership. You should investigate which host is connected on the interface and wether it should be disconnected
System Error Messages Guide For Access and Edge Routers, Cisco IOS XE Gibraltar 16.10.1 - SBC_MPS through TMQ [Cisco IOS XE 16] - Cisco
And a description to do some IPv6 snooping and IPv6 First Hop Security settings
Security Configuration Guide, Cisco IOS XE Bengaluru 17.6.x (Catalyst 9200 Switches) - Configuring IPv6 First Hop Security [Support] - Cisco
But I have never done some IPv6 snooping etc. configurations in the past and it seems, that my switches are not aware of those commands.
In conf t there is no ipv6 snooping and also no ipv6 binding table possible to execute.
And now I’m on the point, I have no further ideas … I’m not sure what the Syslog Warning messages triggers, and I don’t know how to fix it.
Anyone else out there with similar issues?
BR
Tom
