Dell EMC Networking OS Configuration Guide for the S5048F–ON System 9.14.2.4

CLI commands are introduced to move /128 IPv6 prefix route entries and /32 IPv4 prefix route entries from Host table to LPM table and vice versa. When moving the destination prefixes from Route to Host table, there is a possibility of getting into hash collision because the Host table on the device is a Hash table. In this scenario, a workaround does not exist for the user having route entries programmed in host table.

When the command is issued, you are prompted with a warning message stating that the command configuration can take effect on existing prefixes only when “clear ip route *” command is used. When you use the clear command, all the existing /32 IPv4 prefix route entries are reprogrammed in appropriate table. Also, all the other existing IPv4 entries are removed and reprogrammed as a result of the clear command.

Dell EMC Networking OS releases earlier than Release 9.3(0.1) stores IPv6 /128 entries in Host table since it cannot be written in LPM table, and IPv4 0/32 route entries are written in LPM table itself to support the ECMP since ECMP was not supported in Host table. On the system, unified forwarding table (UFT) is enabled, and the host table size is bigger compared to the LPM. When you move the IPv4 /32 route prefix entry in host table, more space is obtained that can be utilized for other route prefix entries.