From: Alejandro Cadarso (a.cadarso@xxxxxxxxxxxxxx)
Date: Wed Sep 06 2000 - 14:21:34 GMT-3
Your rtr A can't answer the pings from router C or D because it doesn't know
how to reach any IP address from them.
If you issue a sh ip route in it you'll see that it only knows network
192.1.1.0/24 and for this it can answer pings from rtr B.
Alejandro
Ola Aiyegbusi wrote:
>
> Sorry about that. Here are the configs (somewhat truncated) ::
>
> RTR A#sh run!
> hostname RTR A
> ip subnet-zero
> no ip domain-lookup
> !
> interface Loopback0
> ip address 1.1.1.1 255.255.255.0
> no ip directed-broadcast
> !
> interface Ethernet0
> no ip address
> no ip directed-broadcast
> shutdown
> !
> interface Serial0
> no ip address
> no ip directed-broadcast
> shutdown
> no fair-queue
> !
> interface Serial1
> ip address 192.1.1.1 255.255.255.0
> no ip directed-broadcast
> clockrate 500000
> !
> router bgp 100
> network 1.0.0.0
> neighbor 192.1.1.2 remote-as 200
> !
> no ip classless
> !
> snmp-server community public RO
> snmp-server community private RW
> !
> end
>
> RTR B#sh run
> version 12.0
> !
> hostname RTR B
> !
> ip subnet-zero
> no ip domain-lookup
> !
> interface Loopback0
> ip address 2.2.2.2 255.255.255.0
> no ip directed-broadcast
> !
> interface Ethernet0
> ip address 193.1.1.2 255.255.255.0
> no ip directed-broadcast
> !
> interface Serial0
> no ip address
> no ip directed-broadcast
> shutdown
> !
> interface Serial1
> ip address 192.1.1.2 255.255.255.0
> no ip directed-broadcast
> !
> router ospf 64
> network 0.0.0.0 255.255.255.255 area 0
> !
> router bgp 200
> no synchronization
> neighbor 192.1.1.1 remote-as 100
> neighbor 193.1.1.1 remote-as 200
> !
> ip classless
> !
> snmp-server community public RO
> snmp-server community private RW
> !
> end
>
> RTR C#sh run
> !
> version 11.1
> hostname RTR C
> !
> partition flash 2 8 8
> !
> ip subnet-zero
> no ip domain-lookup
> !
> interface Loopback0
> ip address 3.3.3.3 255.255.255.0
> no ip mroute-cache
> no ip route-cache
> !
> interface Ethernet0
> ip address 193.1.1.1 255.255.255.0
> no ip mroute-cache
> no ip route-cache
> !
> interface Serial0
> description !!!!!!THIS INTERFACE IS NOT WORKING!!!!!!!
> no ip address
> no ip directed-broadcast
> no ip mroute-cache
> no ip route-cache
> shutdown
> !
> interface Serial1
> ip address 194.1.1.1 255.255.255.0
> no ip mroute-cache
> no ip route-cache
> !
> router ospf 64
> network 0.0.0.0 255.255.255.255 area 0
> !
> router bgp 200
> no synchronization
> neighbor 193.1.1.2 remote-as 200
> neighbor 193.1.1.2 route-reflector-client
> neighbor 194.1.1.2 remote-as 200
> neighbor 194.1.1.2 route-reflector-client
> !
> no ip classless
> logging buffered
> !
> end
>
> RTR D#sh run
> version 12.0
> !
> hostname RTR D
> !
> ip subnet-zero
> no ip domain-lookup
>
> !
> interface Loopback0
> ip address 4.4.4.4 255.255.255.0
> no ip directed-broadcast
> !
> interface Serial0/0
> no ip address
> no ip directed-broadcast
> shutdown
> no fair-queue
> clockrate 2015232
> !
> interface Serial0/1
> no ip address
> no ip directed-broadcast
> shutdown
> clockrate 2015232
> !
> interface Serial0/2
> ip address 194.1.1.2 255.255.255.0
> no ip directed-broadcast
> clockrate 503808
> !
> interface Serial0/3
> no ip address
> no ip directed-broadcast
> shutdown
> clockrate 2015232
> !
> interface Ethernet1/0
> no ip address
> no ip directed-broadcast
> shutdown
> !
> router ospf 64
> network 0.0.0.0 255.255.255.255 area 0
> !
> router bgp 200
> no synchronization
> neighbor 194.1.1.1 remote-as 200
> !
> ip nat translation timeout neverno ip classless
> !
> snmp-server community public RO
> snmp-server community private RW
> !
> line con 0
> !
> end
>
> ----- Original Message -----
> From: Sanjay Bhakta <sbhakta@charter.net>
> To: <Lachlan_Kidd@data3.com.au>; Ola Aiyegbusi <ola@compath.com>
> Cc: <ccielab@groupstudy.com>
> Sent: Tuesday, September 05, 2000 9:50 PM
> Subject: Re: IBGP, EBGP, AND ROUTE REFLECTORS
>
> > Along with this, rtr A must know how to get back to the router sourcing
> the
> > pings. In your example, router b,c,d may know about network 1.1.1.0,
> > however router a does not know about any of the interfaces on c & d. You
> > can ping from rtr b, because rtr b is directly connected to rtr a, and so
> > the ping source will be the interface between a & b on rtr b.
> >
> > In order to test this, you should also create another loopback and
> advertize
> > it from AS200. For example, create a loopback interface on rtr d, lo0
> > 4.4.4.4 and advertize this. Now do an extended ping from rtr d using
> > 4.4.4.4 as source.
> >
> > And remember what Lachlan said, if there is no IGP in the AS200, you
> should
> > use next-hop-self.
> >
> > ********
> > Sanjay Bhakta (RTP 9/24)
> >
> >
> > ----- Original Message -----
> > From: <Lachlan_Kidd@data3.com.au>
> > To: "Ola Aiyegbusi" <ola@compath.com>
> > Cc: <ccielab@groupstudy.com>
> > Sent: Wednesday, September 06, 2000 7:55 PM
> > Subject: Re: IBGP, EBGP, AND ROUTE REFLECTORS
> >
> >
> > >
> > > Hi Ola,
> > > I would suggest that you need a next-hop-self on rtB. This will
> make
> > > the source of the 1.1.1.0 update appear to be rtrB for C and D. I think
> > the
> > > problem lies in the reachability of the update coming from rtrA. Rember
> > > that with IBGP, the source of the update does not change so C and D will
> > be
> > > seeing the update as coming from RtrA's serial port. C and D may not
> have
> > a
> > > route to that network and hence the old rule of 'do not advertise what
> you
> > > do not know how to reach' applies. No synch only helps with IBGP. You
> > could
> > > try advertising the A-B network with an IGP and see if that fixes the
> > > problem.
> > > I may have this completely wrong so feel free to correct me <grin>.
> > > Regards,
> > > Lachlan.
> > >
> > >
> > >
> > > "Ola
> > > Aiyegbusi" To:
> <ccielab@groupstudy.com>
> >
> > > <ola@compath. cc:
> > > com> Subject: IBGP, EBGP, AND
> > ROUTE REFLECTORS
> > > Sent by:
> > > nobody@groups
> > > tudy.com
> > >
> > >
> > > 05/09/00
> > > 05:06 PM
> > > Please
> > > respond to
> > > "Ola
> > > Aiyegbusi"
> > >
> > >
> > >
> > >
> > >
> > > I have a problem.
> > >
> > > I can't ping an external bgp router (AS100) from another AS (AS200) that
> > > has a route reflector configured with no sync configured on all ibgp
> > > speakers in the AS (AS200)
> > >
> > > a) rtr A (AS100) and rtr B (AS200) are external neighbors connected via
> > > serial. They can ping each other.
> > > b) rtr A is advertising it's loopback address via BGP (1.1.1.1/24)
> > > c) rtr B can ping rtr A's loopback address
> > > d) In AS200, rtr B is connected to rtr C. rtr C is connected to rtr D
> e.g.
> > > (rtrB)--------(rtrC)--------(rtrD)
> > > e) All 3 routers above are in AS 200. rtr B is neighbored with rtrA
> > > (external) and rtrC (internal). rtrC is neighbored with B and D (both
> > > internal. rtr D is neighbored with C (internal)
> > > f) In AS200, rtr C is configured as the route reflector with B and D as
> > > clients
> > > g) The IGP running in AS 200 is OSPF
> > > h) Synchronization has been disabled in all AS 200 IBGP speakers
> > > g) Network 1.0.0.0 (see bullet b above) shows up in the bgp table and
> > > routing table of all IBGP speakers in AS 200
> > >
> > > Problem is: I can't ping 1.1.1.1 from rtr C or D, but I can ping it from
> > > rtr B. HELP!!!!!!!
> > >
> > > Ola Aiyegbusi
> > > ComPath Inc.
> > > 10201 Lee Hwy Suite 140 Fairfax VA 22030
> > > Phone: 703-383-9550 Ext. 122
> > > Pager: 1-888-857-5620
> > > Cell: 703-395-8808
> > > Fax: 703-383-1369
> > > Email: ola@compath.com
> > > Web: http://www.compath.com
> > >
> > >
> > >
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 08:24:53 GMT-3