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 hosttable.When the command is issued, you are prompted with a warning message stating that the command configuration can take effect onexisting prefixes only when “clear ip route *” command is used. When you use the clear command, all the existing /32 IPv4 prefix routeentries are reprogrammed in appropriate table. Also, all the other existing IPv4 entries are removed and reprogrammed as a result of theclear command.Dell 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, andIPv4 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 routeprefix entry in host table, more space is obtained that can be utilized for other route prefix entries.Support for ECMP in host tableECMP support in the L3 host table is available on the system. IPv6 /128 prefix route entries and IPv4 /32 prefix entries which are moved tohost table can have ECMP. For other platforms, only the IPv6 /128 prefix route entries is stored in the L3 host table without ECMPsupport.The software supports a command to program IPv6 /128 route prefixes in the host table.The output of show IPv6 cam command has been enhanced to include the ECMP field in the Neighbor table of Ipv6 CAM. The sampleoutput is displayed as follows, which is similar to the prefix table.The following is the portion of the example output:Neighbor Mac-Addr Port Vid EC------------------------------------- -------------------------[ 132] 20::1 00:00:20:d5:ec:a0 Fo 1/4 0 1[ 132] 20::1 00:00:20:d5:ec:a1 Fo 1/8 0 1Support for moving /128 IPv6 Prefixes and /32 IPv4 PrefixesThe software supports a command to program IPv6 /128 route prefixes in the route table. You can define IPv6 /128 route prefixes in theroute table using the ipv6 unicast-host-routecommand. You can also define IPv4 /32 route prefixes in the host table using theipv4 unicast-host-routecommand.RTAG7RTAG7 is a hashing algorithm that load balances the traffic within a trunk group in a controlled manner. In order to effectively increase thebandwidth of the LAG/Equal Cost Multiple Path routes, traffic is balanced across the member links. The balancing is performed by usingthe RTAG7 hashing, which is designed to have the member links used efficiently as the traffic profile gets more diverse.Hashing-based loadbalancing is used in the following applications:• L3 ECMP• LAGs• HiGig trunkingThe RTAG7 hash scheme generates a hash that consists of the following two portions:• The first portion is primarily generated from packet headers to identify micro-flows in the traffic. The Parameters that are consideredfor hash computations by default in RTAG7 hashing is shown in the given example:Dell#show load-balanceLoad-Balancing Configuration For LAG & ECMP:--------------------------------------------IPV4 Load Balancing EnabledEqual Cost Multi-Path (ECMP) 309
