https://learningnetwork.cisco.com/thread/99664
1. EIGRP Load balancing and EIGRP Traffic Sharing are both different
Load balancing deals with which routes, to the same destination, will be put in the routing table to distribute the traffic.
Traffic sharing deals with how the traffic is transmitted, per-destination or per-packet.
IOS, per-default does load-balancing for all equal-cost routes to the same destination and per-destination sharing to transmit the packets.
You can change this enabling "load-sharing per-packet" in the interface.
Can also use CEF.
The better situation is to do per-packet traffic sharing and again EIGRP has this feature inside of its code.
2. EIGRP Load Balancing is of two types : a.) Equal cost load balancing b.) Unequal cost Load balancing
a) Equal cost - routes with equal metric to the same destination network are put in the routing table
b) Unequal cost - routes with different metrics to the same destination network are put in the routing table (using 'variance' command)
3. In EIGRP equal cost load-balancing, two paths having same metric share equal amount of load (one packet on each path).
EIGRP (and other routing protocols) puts routes with same metric in the routing table by default.
The issue of how packets are transmitted is another thing (per-destination or per-packet).
4. In EIGRP unequal cost load-balancing, two paths with different metrics share equal amount of load (again one packet on each path using variance command)
EIGRP and IGRP are the only protocols that can do unequal cost load-balance.
5. In EIGRP load-sharing, two paths with different metrics share unequal amount of load (one packet through the high cost path and two packets through low cost path)
traffic-sharing where it transmitts using per-packet sharing across different routes.
1) Balanced: EIGRP will do load-sharing inversely proportional of the current metric installed in the RIB.
2) Min across-interfaces : All traffic shared among <min metric> paths using different interfaces for equal-cost paths.
R1# sh ip eigrp topology
P 8.8.8.8/32, 1 successors, FD is 161280
via 192.168.2.2 (161280/158720), FastEthernet0/0
via 192.168.1.1 (1636608/158720), FastEthernet1/0
R1# sh ip route 8.8.8.8 255.255.255.255 longer-prefixes
8.0.0.0/32 is subnetted, 3 subnets
D 8.8.8.8 [90/1636608] via 192.168.1.1, 01:08:37, FastEthernet1/0
[90/161280] via 192.168.2.2, 01:08:37, FastEthernet0/0
R1#
R1# sh ip route 8.8.8.8 255.255.255.255
Routing entry for 8.8.8.8/32
Known via "eigrp 1", distance 90, metric 161280, type internal
Redistributing via eigrp 1
Last update from 192.168.1.1 on FastEthernet1/0, 01:08:32 ago
Routing Descriptor Blocks:
192.168.1.1, from 192.168.1.1, 01:08:32 ago, via FastEthernet1/0
Route metric is 1636608, traffic share count is 1
Total delay is 62930 microseconds, minimum bandwidth is 100000 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 1/255, Hops 3
* 192.168.2.2, from 192.168.2.2, 01:08:32 ago, via FastEthernet0/0
Route metric is 161280, traffic share count is 10
Total delay is 5300 microseconds, minimum bandwidth is 100000 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 1/255, Hops 3
R1#sh ip cef 8.8.8.8 255.255.255.2558.8.8.8/32, version 20, epoch 0, per-destination sharing
0 packets, 0 bytes
via 192.168.1.1, FastEthernet1/0, 0 dependencies
traffic share 1 next hop 192.168.1.1, FastEthernet1/0
valid adjacency
via 192.168.2.2, FastEthernet0/0, 0 dependencies
traffic share 10 next hop 192.168.2.2, FastEthernet0/0
valid adjacency
R1#
Please, check the links bellow for more complete information :
http://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/5212-46.html
http://www.cisco.com/c/en/us/support/docs/ip/enhanced-interior-gateway-routing-protocol-eigrp/13677-19.html