24 | SFTOS Featuresw w w . d e l l . c o m | s u p p o r t . d e l l . c o mLoad Balancing• LAG Load Balancing: For IPv4 packets, LAG load balancing is provided automatically by a hashalgorithm that is based on an XOR (eXclusive OR) of the 3 LSBs (Least Significant Bits) of the sourceand destination IP addresses.For all other packet types, the 3 LSBs of the source and destination MAC addresses are used. Broadcast,unknown unicast, and Layer 2 multicast packets are sent over a single port in the LAG. MAC addresses mustbe learned first in order for load balancing to take place.• ECMP Load Balancing: ECMP (Equal Cost Multi-path Routing) is supported for OSPF, not for RIP.2048 IP routes of the 3072 routes that are supported by SFTOS can be ECMP routes. Six ECMP pathsare supported.ECMP load balancing is like LAG load balancing in that it is provided automatically by a hash algorithm thatis based on an XOR (eXclusive OR) of the 3 LSBs (Least Significant Bits) of the source and destination IPaddresses.Use the maximum-paths command to set the number of paths. For details, see the maximum-paths command inChapter 20, “OSPF Commands”, of the SFTOS Command Reference.Notable Differences between S-Series and E-SeriesThis section describes the major differences in how command usage on the S-Series differs from theE-Series. Users familiar with the E-Series CLI will notice enough similarities in the CLI environment onthe S-Series that they can quickly learn the variations in syntax and usage.The primary goal of SFTOS Release 2.3 (and associated dot releases) was to make SFTOS more likeFTOS. Of course, there are still differences because FTOS requires more commands, usually with moredetailed options than in SFTOS, to support the more complex E-Series switches.• The aaa authentication command: This FTOS command is available in SFTOS as authentication.• CLI command modes: SFTOS Release 2.3 modifies the command mode tree of SFTOS to be morelike FTOS, so that their modes are basically equivalent at the base, differing toward the leaves.• Creating a static route: The SFTOS command ip route supports only IP addresses for setting thenext-hop router, while ip route in the FTOS also supports physical interfaces. In other words:— In SFTOS Layer 3, you can only put an IP address as the source and destination:ip route source-ip-address mask destination-ip-address— In FTOS, you can have a physical interface as a destination as well as an IP address:ip route source-ip-address mask {destination interface | ip address}Note: As you can see in some command descriptions, below, the major difference betweenSFTOS and FTOS is that in commands that contain a port reference, FTOS expresses the locationas slot/port, while SFTOS uses unit/slot/port. For physical identifiers, unit is the stack membernumber in an S50 stack. For details, see Port Naming Convention on page 26.
