Redistribution Between Two EIGRP Autonomous Systems

In Figure 8, the routers are configured as follows:

Router One
router eigrp 2000

!--- The "2000" is the autonomous system

network 172.16.1.0 0.0.0.255
Router Two
router eigrp 2000
redistribute eigrp 1000 route-map to-eigrp2000
network 172.16.1.0 0.0.0.255
!
router eigrp 1000
redistribute eigrp 2000 route-map to-eigrp1000
network 10.1.0.0 0.0.255.255

route-map to-eigrp1000 deny 10
match tag 1000
!
route-map to-eigrp1000 permit 20
set tag 2000
!
route-map to-eigrp2000 deny 10
match tag 2000
!
route-map to-eigrp2000 permit 20
set tag 1000
Router Three
router eigrp 1000
network 10.1.0.0 0.0.255.255
Router Three is advertising the network 10.1.2.0/24 to Router Two through autonomous system 1000; Router Two is redistributing this route into autonomous system 2000 and advertising it to Router One.
Note: The routes from EIGRP 1000 are tagged 1000 before redistributing them to EIGRP 2000. When routes from EIGRP 2000 are redistributed back to EIGRP 1000, the routes with 1000 tags are denied to ensure a loop-free topology. For more information on redistribution among routing protocols, please see Redistributing Routing Protocols.
On Router One, we see:
one# show ip eigrp topology 10.1.2.0 255.255.255.0
IP-EIGRP topology entry for 10.1.2.0/24
State is Passive, Query origin flag is 1, 1 Successor(s), FD is 46763776
Routing Descriptor Blocks:
20.1.1.1 (Serial0), from 20.1.1.1, Send flag is 0x0
Composite metric is (46763776/46251776), Route is External
Vector metric:
Minimum bandwidth is 56 Kbit
Total delay is 41000 microseconds
Reliability is 255/255
Load is 1/255
Minimum MTU is 1500
Hop count is 2
External data:
Originating router is 10.1.2.1
AS number of route is 1000
External protocol is EIGRP, external metric is 46251776
Administrator tag is 1000 (0x000003E
Notice that although the link between Routers One and Two has a bandwidth of 1.544Mb, the minimum bandwidth shown in this topology table entry is 56k. This means that EIGRP preserves all metrics when redistributing between two EIGRP autonomous systems.