Had an case 01280313 with X620 error messages.
May be it can be usefull to add to GTAC knowledge base.
Below error messages often appear
debug hal show ipv4mc
show iproute reserved-entries statistics
show that hardware tables is not filled.
X620 EXOS 188.8.131.52-patch1-2
Upgrade to actual EXOS version - 184.108.40.206