From: Anthony Sequeira (terry.francona@gmail.com)
Date: Thu Nov 24 2005 - 09:31:07 GMT-3
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.
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Thu Dec 01 2005 - 09:12:07 GMT-3