notes: EIGRP Passive Interface, Split Horizon

- The passive-interface command prevents EIGRP hellos from being sent on data links where they don't belong.
- Will prevent neighbor establishments and routes being advertised, as received hellos will be ignored.

The passive-interface command in EIGRP, like in RIPv2, stops the sending of updates out an interface. Unlike RIPv2 however, passive-interface in EIGRP will stop the forming of an adjacency on the interface, and hence the learning of any updates on the link.

The passive-interface default command can be used to make all interfaces passive, and then interfaces can have the passive feature selectively disabled with the no passive-interface command.



command:

Disables the interface from sending hellos

passive-interface {int}

Split-Horizon

- Is always enabled with EIGRP.
- Remember to disable split-horizon with physical multi-point frame-relay interfaces.

command:

interface eth0
no ip split-horizon eigrp {ASN}