Why does sh IPR treat destination networks differently even though at first glance they should be treated the same?
Referring to this diagram: Mah-670-1 and Mah-670-2 are routers serving as the gateway between a building and the larger campus network. Dug-agg-1 and Dug-agg-2 are the aggregation routers that connect them to the OSPF area (0.0.3.2) that they all belong to.
Mah-670-1 has an OSPF P2P link with Dug-agg-1 and with Mah-670-2.
Mah 670-2 has an OSPF P2P link with Dug-agg-2 and with Mah-670-1.
Dug-agg1 and Dug-agg-2 have an OSPF P2P link to each other as well as P2P links to the larger campus network. All P2P and passive VLANs are in the same VR.
The sh ipr for mah-670-1 shows :
#or 10.112.1.0/24 10.3.11.157 12 UG-D---um--f- CA-P2P-Dagg1 4d:22h:16m:17s
#or 10.112.1.0/24 10.3.11.214 12 UG-D---um--f- ca-p2p-Mah-int 4d:22h:16m:17s
#or 10.113.1.0/24 10.3.11.157 10 UG-D---um--c- CA-P2P-Dagg1 4d:22h:16m:17s
#or 10.114.1.0/24 10.3.11.157 10 UG-D---um--c- CA-P2P-Dagg1 4d:22h:16m:17s
All of these routes are #or
Why then, does the 10.112.1.0/24 show two routes in the routing table (one through the Agg, one through the bld partner)
While the 10.113 and 10.114 show only one route (through the agg)?
Please note that both routes appear in the lsdb summary for each network.
Sh ospf lsdb
10.112.1.0 10.56.1.4 0x800009ed 117 0xcccd
10.112.1.0 10.56.2.4 0x800009ef 1091 0xadeb
10.113.1.0 10.56.1.4 0x800030d0 1437 0x7120
10.113.1.0 10.56.2.4 0x80004add 1571 0x 267
10.114.1.0 10.56.1.4 0x800025ed 1437 0x4c32
10.114.1.0 10.56.2.4 0x800025f4 1571 0x373f
The LSDB tells the router about both paths to each network.
The IPR table chooses to show both paths for 112.1, But only one path for 113.1 and 114.1