Hello Mr. Litkowski, Based upon what is represented as your goal and diagram, I would suggest you use a "default-information originate route-map" statement under the ospf process on router A. The route map should clearly identify the bgp routes of interest.
Winston V. Shaw CCIE(#7991) -----Original Message----- From: Stephane LITKOWSKI [mailto:[EMAIL PROTECTED]] Sent: Tuesday, July 23, 2002 12:26 PM To: [EMAIL PROTECTED] Subject: Re: OSPF summarizing BGP redistributed routes into 0/0 [7:49471] Some more informations : LSA for 0.0.0.0 (using summary-address) : CustomerA#sh ip ospf database external OSPF Router with ID (192.168.254.254) (Process ID 1) Type-5 AS External Link States LS age: 5 Options: (No TOS-capability, DC) LS Type: AS External Link Link State ID: 0.0.0.0 (External Network Number ) Advertising Router: 192.168.254.254 LS Seq Number: 80000001 Checksum: 0x2A22 Length: 36 Network Mask: /0 Metric Type: 2 (Larger than any link state path) TOS: 0 Metric: 1 Forward Address: 0.0.0.0 External Route Tag: 0 CustomerA#sh ip ospf database external OSPF Router with ID (192.168.254.254) (Process ID 1) Type-5 AS External Link States Delete flag is set for this LSA LS age: MAXAGE(3600) Options: (No TOS-capability, DC) LS Type: AS External Link Link State ID: 0.0.0.0 (External Network Number ) Advertising Router: 192.168.254.254 LS Seq Number: 80000002 Checksum: 0x301B Length: 36 Network Mask: /0 Metric Type: 2 (Larger than any link state path) TOS: 0 Metric: 16777215 Forward Address: 0.0.0.0 External Route Tag: 1 LSA for 4.0.0.0 & 8.0.0.0 summary routes : CustomerA#sh ip ospf database external OSPF Router with ID (192.168.254.254) (Process ID 1) Type-5 AS External Link States LS age: 11 Options: (No TOS-capability, DC) LS Type: AS External Link Link State ID: 4.0.0.0 (External Network Number ) Advertising Router: 192.168.254.254 LS Seq Number: 80000001 Checksum: 0xEC5E Length: 36 Network Mask: /6 Metric Type: 2 (Larger than any link state path) TOS: 0 Metric: 1 Forward Address: 0.0.0.0 External Route Tag: 0 LS age: 11 Options: (No TOS-capability, DC) LS Type: AS External Link Link State ID: 8.0.0.0 (External Network Number ) Advertising Router: 192.168.254.254 LS Seq Number: 80000002 Checksum: 0xAA9F Length: 36 Network Mask: /5 Metric Type: 2 (Larger than any link state path) TOS: 0 Metric: 1 Forward Address: 0.0.0.0 External Route Tag: 0 LSA 0.0.0.0 using default-originate command -> works fine CustomerA#sh ip ospf database external OSPF Router with ID (192.168.254.254) (Process ID 1) Type-5 AS External Link States LS age: 13 Options: (No TOS-capability, DC) LS Type: AS External Link Link State ID: 0.0.0.0 (External Network Number ) Advertising Router: 192.168.254.254 LS Seq Number: 80000001 Checksum: 0x3C0F Length: 36 Network Mask: /0 Metric Type: 2 (Larger than any link state path) TOS: 0 Metric: 1 Forward Address: 0.0.0.0 External Route Tag: 1 So there's no difference, I just saw that using summary-address, the LSA 0.0.0.0 as an external route tag set to 0 and set to 1 when it is aged out. I done the same test using a cisco 2500 router with IOS 12.2, and it's the same, LSA is prematurely aged out when using summary-address command. Thanks for the help. Stephane ""Stephane LITKOWSKI"" a icrit dans le message de news: [EMAIL PROTECTED] > Hi all, > > I tried to use the "summary-address" OSPF command to summarize learned BGP > routes to a default summary route (0/0) and it seems that it doesn't work. > > (fake BGP routes) ----- router A ------------ 1.0.0.0/32 (OSPF) --------- > router B > > > Router A : > -------------- > > router ospf 1 > log-adjacency-changes > summary-address 0.0.0.0 0.0.0.0 > redistribute bgp 1 subnets > network 1.0.0.0 0.255.255.255 area 0 > ! > router bgp 1 > bgp log-neighbor-changes > network 5.0.0.0 > network 6.0.0.0 > network 7.0.0.0 > network 8.0.0.0 > network 9.0.0.0 > network 10.0.0.0 > ! > ip classless > ip route 5.0.0.0 255.0.0.0 Null0 > ip route 6.0.0.0 255.0.0.0 Null0 > ip route 7.0.0.0 255.0.0.0 Null0 > ip route 8.0.0.0 255.0.0.0 Null0 > ip route 9.0.0.0 255.0.0.0 Null0 > ip route 10.0.0.0 255.0.0.0 FastEthernet0 > > Router B : > -------------- > > router ospf 1 > log-adjacency-changes > network 1.0.0.0 0.255.255.255 area 0 > > > On the router A, I can see that type 5 LSA is installed for 0/0 and > propagated to neighbor : > > CustomerA#sh ip ospf database > > OSPF Router with ID (192.168.254.254) (Process ID 1) > > > Router Link States (Area 0) > > Link ID ADV Router Age Seq# Checksum Link count > 192.168.108.4 192.168.108.4 592 0x80000003 0x6121 2 > 192.168.254.254 192.168.254.254 592 0x80000006 0x7C72 2 > > Type-5 AS External Link States > > Link ID ADV Router Age Seq# Checksum Tag > 0.0.0.0 192.168.254.254 4 0x80000001 0x2A22 0 > > But after some seconds, the external LSA is aged out and so disappears (by > what ????) : > > CustomerA#sh ip ospf database > > OSPF Router with ID (192.168.254.254) (Process ID 1) > > > Router Link States (Area 0) > > Link ID ADV Router Age Seq# Checksum Link count > 192.168.108.4 192.168.108.4 593 0x80000003 0x6121 2 > 192.168.254.254 192.168.254.254 593 0x80000006 0x7C72 2 > > Type-5 AS External Link States > > Link ID ADV Router Age Seq# Checksum Tag > 0.0.0.0 192.168.254.254 3600 0x80000002 0x301B 1 > > CustomerA#sh ip ospf database > > OSPF Router with ID (192.168.254.254) (Process ID 1) > > > Router Link States (Area 0) > > Link ID ADV Router Age Seq# Checksum Link count > 192.168.108.4 192.168.108.4 597 0x80000003 0x6121 2 > 192.168.254.254 192.168.254.254 596 0x80000006 0x7C72 2 > > > If I use another summary-address (like 4.0.0.0/6 or 8.0.0.0/5), it works > fine (external LSAs are not aged out). > > Why this use doesn't work ? What happens ? Why the LSA is aged out ? > The purpose of this test was to conditionnaly advertise default routes (if > BGP routes disappears, default route disappears). > > NB : router A is 1750 router with IOS 12.1(14) > > Thanks for help, > > > -- > Stephane LITKOWSKI > Student in a French computer science school > EPITA Telecom & Network specialization > CCNA + CCNP > EMail : [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=49476&t=49476 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]