From: Brian Dennis (bdennis@internetworkexpert.com)
Date: Mon Mar 28 2005 - 16:14:53 GMT-3
Jongsoo,
Yes, as per RFC 2328 this is what you should expect to see.
Point-to-multipoint and loopback do not advertise out the network
itself. They only advertise out a /32.
There are plenty of times that point-to-multipoint can be useful
in the real world. If you understand what problem the
"point-to-multipoint" network type is designed to solve, you'll
understand where it is used in the real world.
Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
bdennis@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987
Direct: 775-745-6404 (Outside the US and Canada)
-----Original Message-----
From: Jongsoo kim [mailto:bstrt2002@gmail.com]
Sent: Monday, March 28, 2005 10:49 AM
To: Brian Dennis
Cc: ccielab@groupstudy.com
Subject: Re: Having a problem w/ OPSF point-to-multicast
Brian.
Per RFC 2328, it is normal behavior.
For this reason, ospf point-to-multipoint may be only perfect for CCIE
LAB not for else...
Thanks
Jongsoo
On Mon, 28 Mar 2005 13:29:54 -0500, Brian Dennis
<bdennis@internetworkexpert.com> wrote:
> This is as per RFC 2328 (OSPF Version 2).
>
> 12.4.1.4. Describing Point-to-MultiPoint interfaces
>
> For operational Point-to-MultiPoint interfaces, one or
> more link descriptions are added to the router-LSA as
> follows:
>
> o A single Type 3 link (stub network) is added with
> Link ID set to the router's own IP interface
> address, Link Data set to the mask 0xffffffff
> (indicating a host route), and cost set to 0.
>
> o For each fully adjacent neighbor associated with the
> interface, add an additional Type 1 link (point-to-
> point) with Link ID set to the Router ID of the
> neighboring router, Link Data set to the IP
> interface address and cost equal to the interface's
> configured output cost.
>
> As you can see the RFC does not say anything about advertising
> out the network, just the /32's.
>
> http://www.internetworkexpert.com/rfc/rfc2328.txt
>
> Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
>
> bdennis@internetworkexpert.com
> Internetwork Expert, Inc.
> http://www.InternetworkExpert.com
> Toll Free: 877-224-8987
> Direct: 775-745-6404 (Outside the US and Canada)
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> Jongsoo kim
> Sent: Monday, March 28, 2005 10:21 AM
> To: ccielab@groupstudy.com
> Subject: Having a problem w/ OPSF point-to-multicast
>
> Groups
>
> I was doing some lab and found out something strange of OPSF
> point-to-multicast.
> R1 is Hub, R4 and R2 are spokes.
>
> R3-------R1( Hub) .1--------.2 R2( spoke 1),
> | |
> | |
> | .4
> Rip --------------.4 R4( spoke2)
>
> R1,R2, and R4 are OSPF A 0 (172.16.124.0/24)
> R1 and R3 are OSPF A 13.
> R3 and R4 are running rip.(172.16.34.0/24)
>
> Since OPSF p2m is configured, I saw /32 routes on routing table.
> Every OSPF and Rip are working fine....So far so good.
>
> But When I do show ip route on R3,
> I saw /32 host routes of R1,R2,R4(172.16.124.1, 2 ,4) are via OSPF
> But 172.16.124.0/24 are learned by Rip.
> This indicates me OSPF p2m only annouced /32 host route but the subnet
> itself.
>
> But I don't believe this is correct.
> What am I missing ?
>
> Here is output of R3 and
> see "R 172.16.124.0/24 [120/1] via 172.16.34.4, 00:00:12,
> FastEthernet0/1"
>
> ------------------------------R3------------------------------
> R3#show ip route
> Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
> D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
> N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
> E1 - OSPF external type 1, E2 - OSPF external type 2
> i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS
> inter area
> * - candidate default, U - per-user static route, o - ODR
> P - periodic downloaded static route
>
> Gateway of last resort is not set
>
> 70.0.0.0/24 is subnetted, 1 subnets
> B 70.70.70.0 [200/0] via 172.16.36.6, 00:09:14
> 172.16.0.0/16 is variably subnetted, 19 subnets, 4 masks
> C 172.16.140.0/22 is directly connected, Loopback1
> O E2 172.16.25.32/27 [110/20] via 172.16.13.1, 00:00:39, Serial0/0
> C 172.16.36.0/22 is directly connected, FastEthernet0/0
> C 172.16.32.0/22 is directly connected, FastEthernet0/1
> O E2 172.16.25.0/27 [110/20] via 172.16.13.1, 00:00:39, Serial0/0
> D 172.16.16.0/24 [90/30208] via 172.16.36.6, 00:10:57,
> FastEthernet0/0
> O E2 172.16.17.0/24 [110/20] via 172.16.13.1, 00:00:40, Serial0/0
> O IA 172.16.12.0/24 [110/1626] via 172.16.13.1, 00:10:48, Serial0/0
> C 172.16.13.0/24 is directly connected, Serial0/0
> R 172.16.124.0/24 [120/1] via 172.16.34.4, 00:00:12,
> FastEthernet0/1
> O 172.16.124.1/32 [110/64] via 172.16.13.1, 00:10:48, Serial0/0
> O 172.16.124.2/32 [110/64] via 172.16.13.1, 00:10:48, Serial0/0
> O 172.16.124.4/32 [110/128] via 172.16.13.1, 00:10:48, Serial0/0
> R 172.16.120.0/24 [105/1] via 172.16.34.10, 00:00:02,
> FastEthernet0/1
> O 172.16.124.5/32 [110/128] via 172.16.13.1, 00:10:48, Serial0/0
> O 172.16.104.0/24 [110/129] via 172.16.13.1, 00:10:48, Serial0/0
> O E2 172.16.105.0/27 [110/20] via 172.16.13.1, 00:00:40, Serial0/0
> D 172.16.106.0/24 [90/156160] via 172.16.36.6, 00:10:57,
> FastEthernet0/0
> C 172.16.103.0/24 is directly connected, Loopback0
> 10.0.0.0/24 is subnetted, 1 subnets
> R 10.10.10.0 [120/1] via 172.16.34.4, 00:00:13, FastEthernet0/1
>
> Thanks
>
> Jongsoo
>
>
This archive was generated by hypermail 2.1.4 : Sun Apr 03 2005 - 17:56:53 GMT-3