To Reproduce

LR1.wue3(config)# router eigrp 100
LR1.wue3(config-router)# passive-interface eth0
% Configuration failed.

Error type: validation
LR1.wue3(config-router)# passive-interface eth1
% Configuration failed.

Error type: validation

LR1.wue3(config)# interface eth0
LR1.wue3(config-if)# eigrp bandwidth 10
% Configuration failed.

https://github.com/FRRouting/frr/issues/11301#issuecomment-1753246744
Hi all! Sorry for the delay, I couldn't find time for this (
This bug is still relevant, so I have detected two separate issues here:

    Interfaces are not allocated unless topology converges, assuming a network command was issued.
    Looking at similar daemons, I have noticed that ripd is solving this by maintaining a vector.
    This means a separate mapping [iface_name -> iface_passive] and a couple more N.B. callbacks.
    I have pulled this logic into eigrpd and published it via the following branch:
    https://github.com/volodymyrhuti/frr/tree/EIGRP_BUG_NB_11301

    Then I noticed the bandwidth failing with the same message, which sucks a lot.
    From my research, I have found a commented-out callback that should initialize the iface structure.
    eigrp_interface.c -> eigrp_if_init() -> // hook_register_prio(if_add, 0, eigrp_if_new); 
    Implementing it back should fix the config issue and will likely resolve the prior bug.
    P.S. It doesn't fix the prior issue, assuming you want interface-passive default functionality
    However, from testing, it breaks code semantics - allocation is not expected by the rest of the code.
    I'm going to see if I can find semantics divergence, but I'm not sure how long it may take ;(