"IpAddrMgr: Failed to allocate new HW IP multicast [...] table full FIB entry" on a L2-only switch

[HEKnet]

Hello,

we have three switches: (a) 5412zl, (b) 5406zl anc (c) 2910al. The 5412zl is acting as our core switch, is connected to our carrier and L3 routing is enabled (IPv4 and IPv6). The other both switches 5406zl and 2019al only work in L2 mode.

Both L2-only switches send the SNMP trap

IpAddrMgr: Failed to allocate new HW IP multicast [...] table full FIB entry

First question: Why? Is there any reasonable explanation? Why should a L2-only switch be aware of IP addresses at all?

Second question, if there is a reasonable explanation: Why do we not see a similar message from our core L3-switch? This switch has much more traffic/packets to handle.

Last question, if there is still a reasonable explanation: What can we do against it?

Thanks, Matthias