[HECnet] Why does MIM not list 23.1023 as a known node?

A GRE tunnel up from 31.1023 to 23.1023; area 23 nodes are reachable through it, but 23.1023 does not show up in the known nodes list of another router (31.1, openvms 7.3) in the same local network. Both 31.1 and 31.1023 are L2; and 31.1 is connected to MIM via MULTINET. 23.1023 does not show as known to MIM either. But MIM and 31.1 do know about area 23 nodes piglet, owl, rabbit etc. How is 23.1023 going stealth? --------- |31.1 | |IMPVAX |---Multinet/TCP---HECnet --------- | | ----------------- | Bunch of | | Area 31 nodes | ----------------- | | --------- |31.1023| |IMPRTR |---GRE Tunnels to other areas --------- Tunnel from 31.1023 to 23.1023: Area Cost Hops Next Hop to Node Expires Prio *23 4 1 Tunnel23 -> 23.1023 42 64 A+