From: Leigh Harrison (ccileigh@gmail.com)
Date: Thu Nov 24 2005 - 09:44:15 GMT-3
Hey there Anthony,
If you don't want to redistribute bgp into igp (not that popluar with
me!), then you could pop in "next-hop-self".
This way the next hop for the destinations can be found via the igp. No
redistributing required. :)
LH
Anthony Sequeira wrote:
>Hi *Venkataramanaiah.R!*
>You are correct in that we do not need a tunnel for the iBGP peering to work
>between R1 and R4 through R2. As you know - the iBGP peerings do not need to
>be direct connections. The issue will come later with reachability. For
>example - if we advertise a prefix into BGP on R1 - R4 will not have
>reachability due to a "black-hole" situation on R2.
>
>I do not want to redistribute BGP into the IGP here - so I wanted to play
>with the tunnel option as I describe here.
>
>
>
>On 11/24/05, Venkataramanaiah.R <vramanaiah@gmail.com> wrote:
>
>
>>I do not understand the need for tunnel interfaces here for the IBGP
>>to work via R2. Am i missing something here?
>>
>>-Venkat
>>
>>On 11/24/05, Tim <ccie2be@nyc.rr.com> wrote:
>>
>>
>>>A couple things I noticed:
>>>
>>>1) The tunnel endpoints should be on R1 and R4, not R2.
>>>
>>>2) You didn't adjust the cost of the tunnel to make it less preferred
>>>
>>>
>>path
>>
>>
>>>than the physical path.
>>>
>>>3) I would use the physical interface as the tunnel source on each
>>>
>>>
>>router.
>>
>>
>>>4) If using the lo0 for the tunnel ip address doesn't work, you can try
>>>using the ip address of the physical interface for the tunnel address.
>>>
>>>Just a couple ideas,
>>>
>>>Tim
>>>
>>>-----Original Message-----
>>>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
>>>Anthony Sequeira
>>>Sent: Wednesday, November 23, 2005 9:42 PM
>>>To: Cisco certification
>>>Subject: Let's Tunnel BGP Due to Non-BGP Speaker in Transit Path!
>>>
>>>I want to tunnel my iBGP peering from R1 to R4 because R2 is not running
>>>BGP. I want to use the loopback 0 interfaces for the peerings. The IGP
>>>
>>>
>>in
>>
>>
>>>use is EIGRP and all of the interfaces shown below are running EIGRP.
>>>
>>>
>>>
>>>R1-----4.4.8.0/24-----R2-----4.4.12.0/24-----R4
>>>
>>>
>>>
>>>R1 lo0 4.4.1.1/24
>>>
>>>R4 lo0 4.4.4.4/24
>>>
>>>
>>>
>>>I have this sample scenario labbed up and I am having a heck of a time.
>>>
>>>
>>I
>>
>>
>>>have tried the following with no luck:
>>>
>>>
>>>
>>>Attempt 1
>>>
>>>R1:
>>>
>>>int tunnel 0
>>>
>>>ip unnumbered lo0
>>>
>>>tunnel source 4.4.8.1
>>>
>>>tunnel destination 4.4.12.4
>>>
>>>
>>>
>>>R2:
>>>
>>>int tunnel 0
>>>
>>>ip unnumbered lo0
>>>
>>>tunnel source 4.4.12.4
>>>
>>>tunnel destination 4.4.8.1
>>>
>>>
>>>
>>>Attempt 2
>>>
>>>R1:
>>>
>>>int tunnel 0
>>>
>>>ip unnumbered lo0
>>>
>>>tunnel source lo0
>>>
>>>tunnel destination 4.4.4.4
>>>
>>>
>>>
>>>R2:
>>>
>>>int tunnel 0
>>>
>>>ip unnumbered lo0
>>>
>>>tunnel source lo0
>>>
>>>tunnel destination 4.4.1.1
>>>
>>>
>>>
>>>You see this is easy and works great if I create a new subnet for the
>>>tunnel and use that in my BGP peerings the issue that I am having is
>>>trying to use the loopback addresses for the peerings and still use my
>>>tunnel.
>>>
>>>
>>>
>>>I notice that my tunnel interface does not show up in the routing table
>>>
>>>
>>when
>>
>>
>>>I am pulling the address from the loopback..I guess this must be why my
>>>
>>>
>>BGP
>>
>>
>>>is not using it????
>>>
>>>
>>>
>>>Anyone feel like labbing this one up and trying this one? Or is it
>>>
>>>
>>something
>>
>>
>>>really simple that I am missing about tunnels?
>>>
>>>
>>>
>>>Thanks in advance for you consideration of this e-mail.
>>>
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>>>
>
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