From: Jongsoo.Kim@Intelsat.com
Date: Sun Mar 06 2005 - 00:11:51 GMT-3
John
Wow, Now I am lost.
Per CCO, no split-horizon should be issued for rip summary address to be
advertised.
http://www.cisco.com/en/US/products/sw/iosswrel/ps1839/products_command_refe
rence_chapter09186a008010a39d.html#wp1019063
But your lab proved it wrong?
What am I missing here?
Regards
Jongsoo
-----Original Message-----
From: John Murphy [mailto:jt.murphy@comcast.net]
Sent: Saturday, March 05, 2005 9:57 PM
To: Kim, Jongsoo
Cc: ccielab@groupstudy.com
Subject: Re: Summary address for rip
Comments inline
Jongsoo.Kim@Intelsat.com wrote:
>I am sure many of you know about this.
>This is totally news to me. ( I have obvioulsy underestimated the mighty
>RIP!)
>
>As passive interface behaves differently between Rip and EIGRP, so does ip
>summary-address.
>For rip, Ip split-horizon has be to diable for summary-address to be
>advertise, while EIGRP don't care about it.
>
>
I agree that the documentation says this, however in practice it's not
quite so clearcut.... this is on a router running 12.2(15)T12. Example
below....
[R2 --S2/0-]------------[-S2/0 --R4 --S2/0.13-]-------------[-S2/0--R3]
R4#sh ip int Ser2/0.13
Serial2/0.13 is up, line protocol is up
Internet address is 172.10.43.4/24
Broadcast address is 255.255.255.255
Address determined by non-volatile memory
MTU is 1500 bytes
Helper address is not set
Directed broadcast forwarding is disabled
Multicast reserved groups joined: 224.0.0.14 224.0.0.17 224.0.0.1
224.0.0.2
224.0.0.22 224.0.0.13 224.0.0.9
Outgoing access list is not set
Inbound access list is not set
Proxy ARP is enabled
Local Proxy ARP is disabled
Security level is default
Split horizon is enabled <<<<<<<<<<<<<<<<<<<<<<<<<<<< Split Horizon
is enabled
I added three /32 loopbacks on R4...
!
interface Loopback234
ip address 172.10.200.234 255.255.255.255
!
interface Loopback235
ip address 172.10.200.235 255.255.255.255
!
interface Loopback236
ip address 172.10.200.236 255.255.255.255
!
I then configured the summary on Ser2/0.13
interface Serial2/0.13 point-to-point
ip address 172.10.43.4 255.255.255.0
ip pim dense-mode
ip summary-address rip 172.10.200.0 255.255.255.0
frame-relay interface-dlci 403
ip rsvp bandwidth 25 20
!
And on R3....
R3#ship rip
172.10.0.0/16 is variably subnetted, 19 subnets, 6 masks
R 172.10.200.0/24 [120/1] via 172.10.43.4, 00:00:06, Serial2/0
R 172.10.25.0/29 [120/1] via 172.10.43.4, 00:00:06, Serial2/0
R 172.10.25.64/26 [89/1] via 172.10.43.4, 00:00:06, Serial2/0
It's just another IGP, don't let it psych you out....
jm
############################################################
Building on 40 Years of Leadership - As a global communications leader with 40 years of experience, Intelsat helps service providers,
broadcasters, corporations and governments deliver information and entertainment anywhere in the world, instantly, securely and reliably.
############################################################
This email message is for the sole use of the intended
recipient(s) and may contain confidential and privileged
information. Any unauthorized review, use, disclosure or
distribution is prohibited. If you are not the intended
recipient, please contact the sender by reply email and
destroy all copies of the original message. Any views
expressed in this message are those of the individual
sender, except where the sender specifically states them
to be the views of Intelsat, Ltd. and its subsidiaries.
############################################################
This archive was generated by hypermail 2.1.4 : Sun Apr 03 2005 - 17:56:41 GMT-3