From: SFeldberg@xxxxxxxxxxxxx
Date: Fri Nov 09 2001 - 14:06:52 GMT-3
This is EVIL.
The same topology, same network redistributed into OSPF and EIGRP. As
Liekun stated earlier, EIGRP allows the BGP route to become synchronized,
OSPF does not. End result is that this network will not be considered
"best" by R2 when using OSPF as the IGP.
To answer the question
> Is the nexthop 133.3.13.3 reachable from R2?
RTR-2#sh ip route
100.0.0.0/24 is subnetted, 1 subnets
O IA 100.100.1.0 [110/75] via 133.3.12.1, 00:07:27, Serial0
133.3.0.0/16 is variably subnetted, 7 subnets, 2 masks
C 133.3.2.0/24 is directly connected, Loopback0
D 133.3.3.0/24 [90/2297856] via 133.3.23.3, 00:22:16, Serial1
D 133.3.1.0/24 [90/2297856] via 133.3.12.1, 00:22:14, Serial0
C 133.3.12.0/24 is directly connected, Serial0
O 133.3.12.1/32 [110/64] via 133.3.12.1, 00:45:09, Serial0
D 133.3.13.0/24 [90/2195456] via 133.3.12.1, 00:22:16, Serial0
[90/2195456] via 133.3.23.3, 00:22:16, Serial1
C 133.3.23.0/24 is directly connected, Serial1
RTR-2#ping 133.3.13.3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 133.3.13.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 32/33/36 ms
Here's what it looks like when it works properly with EIGRP
RTR-2#sh ip route
100.0.0.0/24 is subnetted, 1 subnets
D EX 100.100.1.0 [170/2560512256] via 133.3.23.3, 00:02:42, Serial1
133.3.0.0/24 is subnetted, 6 subnets
C 133.3.2.0 is directly connected, Loopback0
D 133.3.3.0 [90/2297856] via 133.3.23.3, 00:04:38, Serial1
D 133.3.1.0 [90/2297856] via 133.3.12.1, 00:04:38, Serial0
C 133.3.12.0 is directly connected, Serial0
D 133.3.13.0 [90/2195456] via 133.3.12.1, 00:04:38, Serial0
[90/2195456] via 133.3.23.3, 00:04:38, Serial1
C 133.3.23.0 is directly connected, Serial1
RTR-2#sh ip bgp
BGP table version is 2, local router ID is 133.3.2.2
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
*>i100.100.1.0/24 133.3.13.3 10 100 0 ?
When OSPF is the IGP
RTR-2#sh ip route
100.0.0.0/24 is subnetted, 1 subnets
O E2 100.100.1.0 [110/20] via 133.3.23.3, 00:00:15, Serial1
133.3.0.0/24 is subnetted, 6 subnets
C 133.3.2.0 is directly connected, Loopback0
D 133.3.3.0 [90/2297856] via 133.3.23.3, 00:21:00, Serial1
D 133.3.1.0 [90/2297856] via 133.3.12.1, 00:21:00, Serial0
C 133.3.12.0 is directly connected, Serial0
D 133.3.13.0 [90/2195456] via 133.3.12.1, 00:21:00, Serial0
[90/2195456] via 133.3.23.3, 00:21:00, Serial1
C 133.3.23.0 is directly connected, Serial1
RTR-2#sh ip bgp
BGP table version is 3, local router ID is 133.3.2.2
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
* i100.100.1.0/24 133.3.13.3 10 100 0 ?
I also tried to change the LSA type of the 100.100.1.0 network in OSPF
RTR-2#sh ip route
100.0.0.0/24 is subnetted, 1 subnets
O IA 100.100.1.0 [110/65] via 133.3.23.3, 00:00:32, Serial1
133.3.0.0/24 is subnetted, 6 subnets
C 133.3.2.0 is directly connected, Loopback0
D 133.3.3.0 [90/2297856] via 133.3.23.3, 00:40:23, Serial1
D 133.3.1.0 [90/2297856] via 133.3.12.1, 00:40:23, Serial0
C 133.3.12.0 is directly connected, Serial0
D 133.3.13.0 [90/2195456] via 133.3.12.1, 00:40:23, Serial0
[90/2195456] via 133.3.23.3, 00:40:23, Serial1
C 133.3.23.0 is directly connected, Serial1
Still, no love...
RTR-2#sh ip bgp
BGP table version is 1, local router ID is 133.3.2.2
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
* i100.100.1.0/24 133.3.13.3 10 100 0 ?
Again, when the route is advertised by EIGRP
RTR-2#sh ip route
100.0.0.0/24 is subnetted, 1 subnets
D EX 100.100.1.0 [170/2560512256] via 133.3.23.3, 00:00:08, Serial1
133.3.0.0/24 is subnetted, 6 subnets
C 133.3.2.0 is directly connected, Loopback0
D 133.3.3.0 [90/2297856] via 133.3.23.3, 01:03:11, Serial1
D 133.3.1.0 [90/2297856] via 133.3.12.1, 01:03:11, Serial0
C 133.3.12.0 is directly connected, Serial0
D 133.3.13.0 [90/2195456] via 133.3.12.1, 01:03:11, Serial0
[90/2195456] via 133.3.23.3, 01:03:11, Serial1
C 133.3.23.0 is directly connected, Serial1
Routing table entry detail
RTR-2#sh ip bgp 100.100.1.0
BGP routing table entry for 100.100.1.0/24, version 2
Paths: (1 available, best #1)
Not advertised to any peer
Local
133.3.13.3 (metric 2195456) from 133.3.12.1 (133.3.3.3)
Origin incomplete, metric 10, localpref 100, valid, internal,
synchronized, best, ref 2
Originator: 133.3.3.3, Cluster list: 133.3.1.1
Again, when the route is advertised by OSPF
RTR-2#sh ip route
100.0.0.0/24 is subnetted, 1 subnets
O IA 100.100.1.0 [110/65] via 133.3.23.3, 00:01:39, Serial1
133.3.0.0/24 is subnetted, 6 subnets
C 133.3.2.0 is directly connected, Loopback0
D 133.3.3.0 [90/2297856] via 133.3.23.3, 01:02:00, Serial1
D 133.3.1.0 [90/2297856] via 133.3.12.1, 01:02:00, Serial0
C 133.3.12.0 is directly connected, Serial0
D 133.3.13.0 [90/2195456] via 133.3.12.1, 01:02:00, Serial0
[90/2195456] via 133.3.23.3, 01:02:00, Serial1
C 133.3.23.0 is directly connected, Serial1
Routing table entry detail
RTR-2#sh ip bgp 100.100.1.0
BGP routing table entry for 100.100.1.0/24, version 0
Paths: (1 available, no best path)
Not advertised to any peer
Local
133.3.13.3 (metric 2195456) from 133.3.12.1 (133.3.3.3)
Origin incomplete, metric 10, localpref 100, valid, internal, not
synchronized, ref 2
Originator: 133.3.3.3, Cluster list: 133.3.1.1
Notice that the network is "not synchronized"
All IOS are current:
RTR-1#sh ver
Cisco Internetwork Operating System Software
IOS (tm) 2500 Software (C2500-JOS56I-L), Version 12.0(19), RELEASE SOFTWARE
(fc1)
RTR-3#sh ver
Cisco Internetwork Operating System Software
IOS (tm) 2500 Software (C2500-DS-L), Version 12.0(20), RELEASE SOFTWARE
(fc1)
RTR-2#sh ver
Cisco Internetwork Operating System Software
IOS (tm) 2500 Software (C2500-JOS56I-L), Version 12.0(19), RELEASE SOFTWARE
(fc1)
More info about routing and BGP table entries:
With OSPF
RTR-2#sh ip bgp
Network Next Hop Metric LocPrf Weight Path
* i100.100.1.0/24 133.3.13.3 10 100 0 ?
RTR-1#sh ip bgp 100.100.1.0
BGP routing table entry for 100.100.1.0/24, version 2
Paths: (1 available, best #1)
Advertised to non peer-group peers:
133.3.12.2
Local, (Received from a RR-client)
133.3.13.3 from 133.3.13.3 (133.3.3.3)
Origin incomplete, metric 10, localpref 100, valid, internal,
synchronized, best, ref 2
RTR-1#sh ip route 100.100.1.0
Routing entry for 100.100.1.0/24
Known via "ospf 100", distance 110, metric 11, type inter area
Redistributing via ospf 100
Last update from 133.3.13.3 on Ethernet0, 00:17:19 ago
Routing Descriptor Blocks:
* 133.3.13.3, from 133.3.3.3, 00:17:19 ago, via Ethernet0
Route metric is 11, traffic share count is 1
RTR-2#sh ip bgp 100.100.1.0
BGP routing table entry for 100.100.1.0/24, version 0
Paths: (1 available, no best path)
Not advertised to any peer
Local
133.3.13.3 (metric 74) from 133.3.12.1 (133.3.3.3)
Origin incomplete, metric 10, localpref 100, valid, internal, not
synchronized, ref 2
Originator: 133.3.3.3, Cluster list: 133.3.1.1
RTR-2#sh ip route 100.100.1.0
Routing entry for 100.100.1.0/24
Known via "ospf 100", distance 110, metric 75, type inter area
Redistributing via ospf 100
Last update from 133.3.12.1 on Serial0, 00:20:03 ago
Routing Descriptor Blocks:
* 133.3.12.1, from 133.3.3.3, 00:20:03 ago, via Serial0
Route metric is 75, traffic share count is 1
With EIGRP
RTR-2#sh ip bgp
Network Next Hop Metric LocPrf Weight Path
*>i100.100.1.0/24 133.3.13.3 10 100 0 ?
RTR-1#sh ip bgp 100.100.1.0
BGP routing table entry for 100.100.1.0/24, version 5
Paths: (1 available, best #1)
Advertised to non peer-group peers:
133.3.12.2
Local, (Received from a RR-client)
133.3.13.3 from 133.3.13.3 (133.3.3.3)
Origin incomplete, metric 10, localpref 100, valid, internal,
synchronized, best, ref 2
RTR-1#sh ip route 100.100.1.0
Routing entry for 100.100.1.0/24
Known via "eigrp 1", distance 170, metric 2560025856, type external
Redistributing via eigrp 1
Last update from 133.3.13.3 on Ethernet0, 00:01:06 ago
Routing Descriptor Blocks:
* 133.3.13.3, from 133.3.13.3, 00:01:06 ago, via Ethernet0
Route metric is 2560025856, traffic share count is 1
Total delay is 1010 microseconds, minimum bandwidth is 1 Kbit
Reliability 1/255, minimum MTU 1 bytes
Loading 1/255, Hops 1
RTR-2#sh ip bgp
Network Next Hop Metric LocPrf Weight Path
*>i100.100.1.0/24 133.3.13.3 10 100 0 ?
RTR-2#sh ip bgp 100.100.1.0
BGP routing table entry for 100.100.1.0/24, version 2
Paths: (1 available, best #1)
Not advertised to any peer
Local
133.3.13.3 (metric 2195456) from 133.3.12.1 (133.3.3.3)
Origin incomplete, metric 10, localpref 100, valid, internal,
synchronized, best, ref 2
Originator: 133.3.3.3, Cluster list: 133.3.1.1
RTR-2#sh ip route 100.100.1.0
Routing entry for 100.100.1.0/24
Known via "eigrp 1", distance 170, metric 2560512256, type external
Redistributing via eigrp 1
Last update from 133.3.23.3 on Serial1, 00:00:41 ago
Routing Descriptor Blocks:
* 133.3.23.3, from 133.3.23.3, 00:00:41 ago, via Serial1
Route metric is 2560512256, traffic share count is 1
Total delay is 20010 microseconds, minimum bandwidth is 1 Kbit
Reliability 1/255, minimum MTU 1 bytes
Loading 1/255, Hops 1
The only difference I can see in the output between the protocols is in the
routing descriptor blocks.
OSPF on R2
* 133.3.12.1, from 133.3.3.3, 00:20:03 ago, via Serial0
EIGRP on R2
* 133.3.23.3, from 133.3.23.3, 00:00:41 ago, via Serial1
When the "* x.x.x.x, from x.x.x.x" values match, the route is becomes
synchronized. This is now "driving me to the brink of drink" as another
member colorfully stated in an earlier post.... any thoughts???!
Stephen Feldberg
e ^ deltacom
phone: 678.835.5437
sfeldberg@edeltacom.com
"Chua, Parry"
<Parry.Chua@c To: "'Liekun Ye'" <liekun@chinawea
l.com>,
ompaq.com> SFeldberg@edeltacom.com
Sent by: cc: ccielab@groupstudy.com, nobody
@groupstudy.com
nobody@groups Subject: RE: BGP synchro problem
tudy.com
11/08/2001
10:28 PM
Please
respond to
"Chua, Parry"
Hi,
Since R1 is the RR for R2 and R3, in R1 bgp table, it has receive the
update
from R3. R1 has
send the update to R2 bgp as expected , only R2 does not consider it is
valid. It the next
hop 133.3.13.3 reachable from R2 ?
> Parry Chua
>
-----Original Message-----
From: Liekun Ye [mailto:liekun@chinaweal.com]
Sent: Friday, November 09, 2001 10:06 AM
To: SFeldberg@edeltacom.com
Cc: ccielab@groupstudy.com; nobody@groupstudy.com
Subject: RE: BGP synchro problem
Ok, Here is my real configure, Pls help me to figure it out. TKS.
Here is my config on R1/R2/R3
Configure on R1
=========================================
hostname RTR-1
!
!
ip subnet-zero
!
!
!
!
!
interface Loopback0
ip address 133.3.1.1 255.255.255.0
no ip directed-broadcast
ip ospf network point-to-point
!
interface Ethernet0
ip address 133.3.13.1 255.255.255.0
no ip directed-broadcast
!
interface Ethernet1
no ip address
no ip directed-broadcast
!
interface Serial0
ip address 133.3.12.1 255.255.255.0
no ip directed-broadcast
clockrate 2000000
!
interface Serial1
no ip address
no ip directed-broadcast
shutdown
!
router ospf 100
network 133.3.34.0 0.0.0.255 area 0
network 133.3.0.0 0.0.255.255 area 0
!
router bgp 100
neighbor 133.3.12.2 remote-as 100
neighbor 133.3.12.2 route-reflector-client
neighbor 133.3.13.3 remote-as 100
neighbor 133.3.13.3 route-reflector-client
no auto-summary
!
ip classless
>>>>show ip bgp <<<< output
BGP table version is 2, local router ID is 133.3.1.1
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
*>i100.100.1.0/24 133.3.13.3 10 100 0 ?
Configure on R2
===========================================
interface Loopback0
ip address 133.3.2.2 255.255.255.0
no ip directed-broadcast
ip ospf network point-to-point
!
interface Serial0
ip address 133.3.12.2 255.255.255.0
no ip directed-broadcast
!
interface Serial1
ip address 133.3.23.2 255.255.255.0
no ip directed-broadcast
clockrate 2000000
!
interface TokenRing0
no ip address
no ip directed-broadcast
shutdown
ethernet-transit-oui 90-compatible
ring-speed 16
source-bridge 10 1 100
source-bridge spanning 100
!
router ospf 100
network 133.3.0.0 0.0.255.255 area 0
!
router bgp 100
bgp router-id 133.3.2.2
neighbor 133.3.12.1 remote-as 100
!
ip classless
!
>>>>show ip bgp <<<<
BGP table version is 1, local router ID is 133.3.2.2
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
* i100.100.1.0/24 133.3.13.3 10 100 0 ?
======
It's valid, but not best, so will not advertise to another peer, if there
are any.
======
Configure On R3
===================================
interface Loopback0
ip address 133.3.3.3 255.255.255.0
no ip directed-broadcast
ip ospf network point-to-point
!
interface Loopback1
ip address 100.100.1.1 255.255.255.0
no ip directed-broadcast
ip ospf network point-to-point
!
interface Ethernet0/0
ip address 133.3.13.3 255.255.255.0
no ip directed-broadcast
!
interface Serial0/0
ip address 133.3.23.3 255.255.255.0
no ip directed-broadcast
!
interface Ethernet0/1
no ip address
no ip directed-broadcast
shutdown
!
router ospf 100
router-id 133.3.3.3
redistribute connected subnets route-map con2ospf
network 133.3.0.0 0.0.255.255 area 0
!
router bgp 100
bgp router-id 133.3.3.3
redistribute connected metric 10 route-map con2bgp
neighbor 133.3.13.1 remote-as 100
no auto-summary
!
ip classless
ip http server
!
access-list 1 permit 100.100.1.0
route-map con2bgp permit 10
match ip address 1
!
route-map con2ospf permit 10
match ip address 1
>>>>show ip bgp <<<<output
BGP table version is 6, local router ID is 133.3.3.3
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
*> 100.100.1.0/24 0.0.0.0 10 32768 ?
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
SFeldberg@edeltacom.com
Sent: Friday, November 09, 2001 4:54 AM
To: Liekun Ye
Cc: ccielab@groupstudy.com; nobody@groupstudy.com
Subject: Re: BGP synchro problem
You say that you have redistributed the route into BGP on R3. Is this
where are you redistributing 100.100.1.0 into OSPF as well? I have a hunch
that it is your redistribution of this network is the answer to your
question about why EIGRP works but OSPF does not. Remember that the key to
synchronization is having a valid entry in the routing table. If the BGP
route is invalid on R2, then you need to investigate why R2 is not learning
about 100.100.1.0 from the OSPF protocol.
Steve
"Liekun Ye"
<liekun@china To: <ccielab@groupstudy.com>
weal.com> cc:
Sent by: Subject: BGP synchro problem
nobody@groups
tudy.com
11/08/2001
07:33 AM
Please
respond to
"Liekun Ye"
Hi, group,
I have a tough problem in bgp configuration. Look at the scenario
below,
Assume that bgp synchronization is enabled by default. R1 act as RR, a
connected
route 100.100.1.0/24 is redistribute into bgp 1 at R3; all three router
runs ospf,
this ibgp route is valid at R1, but shows invalid at R2, also
100.100.1.0/24 is
redistributed to ospf to make igp route synchronize with bgp route. If use
eigrp
to replace ospf as a igp, everything is ok. why ?
Any suggestion is appreciated!
+--------+ +-------+
| | | |
| R1 |------------------| R2 |
+--------+ +---|---+
| |
| |
| |
| |
| +-------+
| | |
+----------------------| R3 |100.100.1.0/24 redis into bgp
| |
+-------+
Liekun Ye
Nov. 3, 2001
This archive was generated by hypermail 2.1.4 : Fri Jun 21 2002 - 06:45:11 GMT-3