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Command with similar function to "passive-interface"

Discussion in 'General Cisco Certifications' started by motorleague, Jun 27, 2007.

  1. motorleague

    motorleague Bit Poster

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    I'm trying to track down a command which I'm sure is in either the Sybex or McGraw Hill CCNA book but I've been unable to find it despite searching them and the net for a good while.

    You can use the "passive-interface" command to prevent an interface sending out routing advertisements but still receiving them, but there's another which can be used to leave the interface neither sending or receiving, and instead push the details out via the other, active interfaces on a router. I believe it's typically used when an interface is attached to a border network with no other routers, so there's no point in it wasting CPU cycles listening for advertisements either.

    There seems to be a way to do this using the distribute-list command and an access list by blocking traffic I think, but I'm sure there's another more suitable way.

    Does this ring any bells? I also seem to recall that the command had several variants, this only being one of it's options.

    If anybody knows, I'd be much appreciative.

    Thanks.

    Alex.
     
    Certifications: MCSA, A+, Network+
    WIP: CCNA, MCSE
  2. Spice_Weasel

    Spice_Weasel Kilobyte Poster

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    The passive-interface command prevents the router sending or receiving eigrp hellos through the interface. That will prevent neighbours from forming, so passive-interface allows a network to be advertised without any routing updates being sent or received through the interface, for eigrp. If you wanted to allow an interface (in eigrp) to receive updates, but not send any, then a distribute-list is the way to do it.

    For OSPF, passive-interface basically makes the interface network appear as a stub area, and no routing information will be sent or received, and no adjacencies formed.

    For rip, the router will will not send updates out a passive interface, but will still receive them.

    In summary, passive-interface prevents EIGRP and OSPF from forming neighbours/adjacancies and sending or receiving updates through the interface, but the network will still be advertised through other, active interfaces. RIP will not send updates through a passive-interface but will receive them.

    Spice_Weasel
     
    Certifications: CCNA, CCNP, CCIP, JNCIA-ER, JNCIS-ER,MCP
    WIP: CCIE
  3. motorleague

    motorleague Bit Poster

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    Thanks for the response. I've since tracked down the command I was looking for - it was:

    distribute connected
     
    Certifications: MCSA, A+, Network+
    WIP: CCNA, MCSE

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