From: John Matus (jmatus@pacbell.net)
Date: Mon Jul 11 2005 - 03:41:00 GMT-3
although i've not read up on the implementation of p2p non broadcast, i
think the jist of the solution is that a 'p2p' non-broadcast is inherently
more secure than a non p2p non-broadcast circuit.....but again, i've not
read up on the technology. there is probably somthing happening at layer 2
that makes it more secure. i'm sure answer is in the wording of the
question, because it does seem that setting up a non-broadcast medium w/
neighbor statement, as well as preventing hello's w/ a passive inteface
command, would fulfill the task requirements.....but only Brian know's the
answer ;-P
Regards,
John D. Matus
MCSE, CCNP
Office: 818-782-2061
Cell: 818-430-8372
jmatus@pacbell.net
----- Original Message -----
From: "Amit Jain" <netsteps@rediffmail.com>
To: "Arun Kumar Arumuganainar" <aarumuga@hotmail.com>; <silamoni@yahoo.com>
Cc: <ccielab@groupstudy.com>
Sent: Sunday, July 10, 2005 11:29 PM
Subject: Re: IE Lab15 Task 5.21
> Thanks Arun, but still I cannot relate your answer to my questions. In my
> Diagram
>
> R3 ----frame-relay----R5 ------isdn-------R4
>
> Do you call this hub and spoke, if they are connected together through
> different WAN topology??
> R3 and R5 are on non-broadcast default mode for which neighbor statement
> is
> configured.
> R5 and R4 are on point-to-point mode as what i seee from "sh ip ospf inter
> bri0/0"
>
> Ques asked to prevent hello packets to anyone hooking on to this topology.
> Sol says that configure point-to-multipoint non-broadcast on all the
> routers.
> My Ques : Why to configure point-to-multipoint non-broadcast when the
> default network type between R3 and R5 is non-br and sending unicast (so
> nobody can hook on this segment and see hello) AND
> Why to configure point-to-multipoint non-broadcast between R5 and R4 when
> default network type point-to-point will prevent leaking of hellos, as the
> hellos will only go to other side.
>
> What am I missing?
>
> AMit
>
> ----- Original Message -----
> From: "Arun Kumar Arumuganainar" <aarumuga@hotmail.com>
> To: <silamoni@yahoo.com>
> Cc: <ccielab@groupstudy.com>
> Sent: Sunday, July 10, 2005 5:14 PM
> Subject: Re: IE Lab15 Task 5.21
>
>
>> For Fram Relay Networks , Default Mode in Frame Relay Network is NBMA .
>> But this will work only with Fully Meshed network .In Hub and Spoke
>> topology full connectivity can not be achived . Spoke routers will only
>> be able to ping Hub router and none of the other spoke routers.
>>
>> Note :In the above scenario OSPF neighborship will get established .
>> Routing table will get populated as normal . But however , connectivity
>> alone will not be there across the Spokes .This Problem will also be seen
>> in Partially meshed networks as well .
>>
>> By making the Network type Point to Multipoint you can over come this
>> problem . Actually if you inspect the routing table on the point to
>> Multipoint network , you will be able to observe host route ( Route with
>> /32 Bit mask ) for all connected IP address . This will enable routing
>> possible between spokes !!!
>>
>> Pls. Note : You could add broadcast keyword appended to point to
>> Multipoint . In case you are not allowed to configure broadcast key word
>> then you will have manually configure neighbour statement . This will
>> enable OSPF packets to unicasted over the FR Cloud .
>>
>> Hope this helps.
>>
>> Thanks and Regards
>> Arun
>>
>> >From: Sila Moni <silamoni@yahoo.com>
>> >Reply-To: Sila Moni <silamoni@yahoo.com>
>> >To: Amit Jain <netsteps@rediffmail.com>, Group Study <>
>> >Subject: Re: IE Lab15 Task 5.21
>> >Date: Sat, 9 Jul 2005 05:52:29 -0700 (PDT)
>> >
>> >There are two issues that I see from this scenario.
>> >
>> >1. Typically, you would use the neighbor statement on
>> >the hub. Since it is on R3 (spoke), it will create
>> >some problems. Are you allowed to put the neighbor
>> >statement on R4 as well?
>> >
>> >2. P-T-M non-broadcast is used in NBMA with virtual
>> >circuits of differing speeds (e.g. ISDN and FR).
>> >Here, assigning cost to the neighbor is optional.
>> >
>> >
>> >--- Amit Jain <netsteps@rediffmail.com> wrote:
>> >
>> > > Hi
>> > >
>> > > In the task, R3 and R5 are connected through frame
>> > > relay and R4 and R5 through
>> > > ISDN
>> > >
>> > > R3
>> > > -
>> > > -
>> > > - FR -
>> > > -
>> > >
>> > > R4 - -ISDN - - R5
>> > >
>> > > Now the ospf area 345 is running on FR and ISDN
>> > > links and network type
>> > > non-broadcast between R3 and R5, with neighbor
>> > > command on R3.
>> > > Task requirement is to configure all adjacencies in
>> > > area 345 in such a manner
>> > > that other devices on segment cannot recieve OSPF
>> > > hello packets.
>> > > The solution given is that the network type on ISDN
>> > > and FR segment be changed
>> > > to point-to-multipoint (with ofcourse neighbor
>> > > statements)
>> > >
>> > > My ques is why we need to change it to
>> > > point-to-multpoint from non-broadcast
>> > > on FR segment ? When the netwrk type is
>> > > non-broadcast we are sending packets
>> > > as unicast only, so why specifically change to
>> > > p-to-multipoint ?? (Only
>> > > difference will be no DR/BDR elec and host route)
>> > >
>> > > Also the ISDN segment is network type point-to-point
>> > > so anyways the hello
>> > > packets will only go to the other side ?? What am i
>> > > missing.
>> > >
>> > > Could not get the answer from IE website posts.
>> > >
>> > > Thanks
>> > > Amit Jain
>> > >
>> > >
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