12-04-2009 05:52 AM - edited 03-06-2019 08:49 AM
hello experts
when we issue the command (passive-interface) in ospf configuration on a specific interface, will this command prevent sending and receiving the update packet or prevent sending only and allow for receiving like rip and igrp, thankyou for your response
Labib
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12-04-2009 05:54 AM
labibmakar wrote:
hello experts
when we issue the command (passive-interface) in ospf configuration on a specific interface, will this command prevent sending and receiving the update packet or prevent sending only and allow for receiving like rip and igrp, thankyou for your response
Labib
Labib
Passive interface on an OSPF interface will stop it forming any adjacencies/neighborships with other routers on that subnet so it never gets to the stage of sending or receiving routes.
Jon
12-04-2009 06:22 AM
Hello Labib,
OSPF, IS-IS and EIGRP have the neighbor state machine concept: they don't accept routes from a device that doesn't qualify as a neighbor so the passive-interface doesn't allow to have a device listening on the link, as it happens with older and simpler routing protocols like RIP and IGRP.
the passive-interface combined with other commands (protocol dependent) allows to advertise the IP subnet of the involved interface(s).
Hope to help
Giuseppe
12-04-2009 05:54 AM
labibmakar wrote:
hello experts
when we issue the command (passive-interface) in ospf configuration on a specific interface, will this command prevent sending and receiving the update packet or prevent sending only and allow for receiving like rip and igrp, thankyou for your response
Labib
Labib
Passive interface on an OSPF interface will stop it forming any adjacencies/neighborships with other routers on that subnet so it never gets to the stage of sending or receiving routes.
Jon
12-04-2009 05:58 AM
Hello Labib,
If you disable the sending of routing updates on an interface, the particular subnet will continue to be advertised to other interfaces, and updates from other routers on that interface continue to be received and processed.
HTH
Reza
12-04-2009 06:07 AM
sharifimr wrote:
Hello Labib,
If you disable the sending of routing updates on an interface, the particular subnet will continue to be advertised to other interfaces, and updates from other routers on that interface continue to be received and processed.
HTH
Reza
Reza
I agree that the subnet will be advertised to other neighbors but no updates on the passive-interface will be received and processed because no adjacency/neighborships can be formed therefore there will be no updates.
Or have i misunderstood what you wrote ?
Jon
12-04-2009 06:19 AM
Jon,
You are right. It would be on the particular interface only and since there is no adjacency so there will be no other updates.
Thanks for the correction
Reza
12-04-2009 06:22 AM
Hello Labib,
OSPF, IS-IS and EIGRP have the neighbor state machine concept: they don't accept routes from a device that doesn't qualify as a neighbor so the passive-interface doesn't allow to have a device listening on the link, as it happens with older and simpler routing protocols like RIP and IGRP.
the passive-interface combined with other commands (protocol dependent) allows to advertise the IP subnet of the involved interface(s).
Hope to help
Giuseppe
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