Ken,
When the passive-interface command is used in EIGRP, the router cannot form neighbor adjacencies on the interface, or send or receive routing updates. However, if you want the outgoing routing updates alone be suppressed but the inbound updates continue to be received (and the routers still continue to be neighbors), then use the distribute-list command as follows:
R1(config)# access-list 20 deny any
R1(config)# router eigrp 1
R1(config-router)# distribute-list 20 out fa0/0
check out the link for more details
http://www.cisco.com/en/US/partner/tech/tk365/technologies_tech_note09186a0080093f0a.shtml
However when you run RIP you can achieve this with the neighbor command
interface fa 0/0
ip address 172.16.100.3 255.255.255.0
router rip
network 172.16.100.0
passive-interface fa 0/0
neighbor 172.16.100.1
neighbor 172.16.100.2
HTH, rate if it does
Narayan
