Symptom

EIGRP redistribution entries are sometimes in the topology table, sometimes not in the topology table, depending on the order in which EIGRP neighbors are established. AS 100 AS 65002 R1-------------N7K----------------R2 R1 and R2 send route 10.10.10.0/24 to N7K, then N7K redistribute this route to EIGRP AS 100. If EIGRP 100 neighbor up first, then route 10.10.10.0/24 will ECMP between R1 and R2. Topology table have no redistribute entry: N7K-C7009-1(config-router)# show ip route 10.10.10.0/24 IP Route Table for VRF "default" '*' denotes best ucast next-hop '**' denotes best mcast next-hop '[x/y]' denotes [preference/metric] '%' in via output denotes VRF 10.10.10.0/24, ubest/mbest: 2/0 *via 10.71.51.X, Eth4/5, [170/281856], 00:00:02, eigrp-65002, external *via 10.71.72.X, Vlan1911, [170/281856], 00:00:06, eigrp-100, external N7K-C7009-1(config-router)# show ip eigrp topology 10.10.10.0/24 IP-EIGRP (AS 100): Topology entry for 10.10.10.0/24 State is Passive, Query origin flag is 1, 1 Successor(s), FD is 281856 Routing Descriptor Blocks: 10.71.72.X (Vlan1911), from 10.71.72.X, Send flag is 0x0 Composite metric is (281856/281600), Route is External Vector metric: Minimum bandwidth is 10000 Kbit Total delay is 1010 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 1 Internal tag is 0 External data: Originating router is 172.16.72.X AS number of route is 65002 External protocol is EIGRP, external metric is 281856 Administrator tag is 0 (0x00000000) IP-EIGRP (AS 65002): Topology entry for 10.10.10.0/24 State is Passive, Query origin flag is 1, 1 Successor(s), FD is 281856 Routing Descriptor Blocks: 10.71.51.X (Ethernet4/5), from 10.71.51.X, Send flag is 0x0 Composite metric is (281856/281600), Route is External Vector metric: Minimum bandwidth is 10000 Kbit Total delay is 1010 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 1 Internal tag is 0 External data: Originating router is 172.16.51.X AS number of route is 0 External protocol is Connected, external metric is 0 Administrator tag is 0 (0x00000000) But if EIGRP AS 65002 neighbor up first, only neighbor AS 65002 will add in RIB. Topology table will generate redistribute entry: N7K-C7009-1(config-router)# clear ip eigrp 100 nei * N7K-C7009-1(config-router)# N7K-C7009-1(config-router)# show ip route 10.10.10.0/24 IP Route Table for VRF "default" '*' denotes best ucast next-hop '**' denotes best mcast next-hop '[x/y]' denotes [preference/metric] '%' in via output denotes VRF 10.10.10.0/24, ubest/mbest: 1/0 *via 10.71.51.51, Eth4/5, [170/281856], 00:01:01, eigrp-65002, external <<<<<<<<<<<<< N7K-C7009-1(config-router)# show ip eigrp topology 10.10.10.0/24 IP-EIGRP (AS 100): Topology entry for 10.10.10.0/24 State is Passive, Query origin flag is 1, 1 Successor(s), FD is 281600 Routing Descriptor Blocks: 10.71.51.X, from Redistributed, Send flag is 0x0 Composite metric is (281600/0), Route is External Vector metric: Minimum bandwidth is 10000 Kbit Total delay is 1000 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 0 Internal tag is 0 External data: Originating router is 172.16.71.X (this system) <<<<<<<<<<<<<<<<<<< AS number of route is 65002 External protocol is EIGRP, external metric is 281856 Administrator tag is 0 (0x00000000) 10.71.72.X (Vlan1911), from 10.71.72.X, Send flag is 0x0 Composite metric is (281856/281600), Route is External Vector metric: Minimum bandwidth is 10000 Kbit Total delay is 1010 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 1 Internal tag is 0 External data: Originating router is 172.16.72.X AS number of route is 65002 External protocol is EIGRP, external metric is 281856 Administrator tag is 0 (0x00000000) IP-EIGRP (AS 65002): Topology entry for 10.10.10.0/24 State is Passive, Query origin flag is 1, 1 Successor(s), FD is 281856 Routing Descriptor Blocks: 10.71.51.X (Ethernet4/5), from 10.71.51.X, Send flag is 0x0 Composite metric is (281856/281600), Route is External Vector metric: Minimum bandwidth is 10000 Kbit Total delay is 1010 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 1 Internal tag is 0 External data: Originating router is 172.16.51.X AS number of route is 0 External protocol is Connected, external metric is 0 Administrator tag is 0 (0x00000000)

Conditions

R1 and R2 send route 10.10.10.0/24 to N7K, then N7K redistribute this route to EIGRP AS 100. If EIGRP 100 neighbor up first, then route 10.10.10.0/24 will ECMP between R1 and R2. Topology table have no redistribute entry. But if EIGRP AS 65002 neighbor up first, only neighbor AS 65002 will add in RIB. Topology table will generate redistribute entry.

Workaround

There is no workaround.

Further Problem Description