From: jonatale@xxxxxxxxxxxxx
Date: Sat Feb 16 2002 - 15:40:04 GMT-3
The original intent was that each router have a unique ID, this is how other
vendors do it. Cisco allows the router to have a BGP ID and an OSPF ID, I
consider THIS a bug. But instead of fixing the bug they created another
[undocumented] "rule" (so they can make more money on service/training or maybe
because the fix would have required too much work/risk or [God-knows]).
-$0.02
j killion wrote:
> I've heard someone else mention the OSPF/BGP router ID
> rule. What does this rule state and is it documented
> somewhere? Must the ID's be the same for it to work
> w/ "no sync"?
> The same formula is used to calculate the OSPF and BGP
> ID, so wouldn't they be the same (unless you started
> one process, added a loopback, then started the
> other)?
>
> --- "Yadav, Arvind K (CAP, GECIS)"
> <Arvind.Yadav@gecis.ge.com> wrote:
> > Pls check , OSPF router ID must match the BGP router
> > ID
> >
> > Arvind
> >
> >
> > -----Original Message-----
> > From: Tony Hanks
> > [mailto:jhconsulting2001@yahoo.com]
> > Sent: Tuesday, January 15, 2002 11:57 AM
> > To: Bob Sinclair; j killion
> > Cc: ccielab@groupstudy.com
> > Subject: RE: BGP "no sync"
> >
> > Bob,
> >
> > I have to disagree. The route in BGP table is not
> > flagged as a "best" route
> > (>). Hence, BGP will not under any circumstances
> > inject it into the routing
> > table.
> >
> > J,
> >
> > The link might explain why the path isn't marked as
> > "not sync".
> >
> > http://www.cisco.com/warp/public/459/25.shtml
> >
> > Tony Hanks
> > MCSE+I, CCNP
> > Network Infrastructure Engineer
> > J & H Consulting Inc.
> >
> >
> >
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com
> > [mailto:nobody@groupstudy.com]On Behalf Of
> > Bob Sinclair
> > Sent: Monday, January 14, 2002 6:59 PM
> > To: j killion
> > Cc: ccielab@groupstudy.com
> > Subject: Re: BGP "no sync"
> >
> >
> > It seems to me you have no problem. The BGP table
> > shows 100.1.1.0 to be an
> > ibgp route (admin distance 200). The OSPF route is
> > in the IP table (FIB)
> > because it has a lower admin distance (110). I
> > think you will find that if
> > you remove OSPF, the BGP route will take its place,
> > assuming next hop is
> > reachable. Try: sh ip b 100.1.1.0, and see if all
> > is well with the route.
> >
> > -Bob
> >
> > ----- Original Message -----
> > From: "j killion" <jkillion1977@yahoo.com>
> > To: <ccielab@groupstudy.com>
> > Sent: Monday, January 14, 2002 8:43 PM
> > Subject: BGP "no sync"
> >
> >
> > > I thought I understood the operation of IBGP and
> > the
> > > "no sync" cmd, but now I'm not so sure. Correct
> > me if
> > > I'm wrong, but the two IBGP rules that must be met
> > in
> > > order for an IBGP route to become active is 1) The
> > > router must be able to reach the next hop IP, and
> > 2)
> > > There must be a match for the subnet in the IGP
> > table.
> > > The second rule can be circumvented w/ the use of
> > "no
> > > sync"....Sound good so far? How is this
> > explained?
> > >
> > > bart#sh ip bg
> > > BGP table version is 1, local router ID is
> > 152.1.11.1
> > > Status codes: s suppressed, d damped, h history, *
> > > valid, > best, i - internal
> > > Origin codes: i - IGP, e - EGP, ? - incomplete
> > >
> > > Network Next Hop Metric
> > LocPrf
> > > Weight Path
> > > * i100.1.1.0/24 152.1.1.2 0
> > 100
> > > 0 i
> > > bart#ping 152.1.1.2
> > > !!!!!
> > > bart#sh ip rou
> > > 100.0.0.0/24 is subnetted, 1 subnets
> > > O 100.1.1.0 [110/65] via 152.1.1.2, 00:05:53,
> > Serial0
> > >
> > > As you can see, the BGP route isn't active yet I
> > can
> > > ping the next hop IP *and* I have an IGP route for
> > > 100.1.1.0/24. If I add "no sync" the route
> > becomes
> > > active. What am I missing?
> > >
> > > Thanks
> > >
> > >
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