I just labbed this up with R2, R5, and R6, here are my findings. On the hub
(R2) I used a single physical interface (s0/0) and enabled RIP advertising the
150.100.100.0/24 network, I did the same on R5 and R6. Next I verified that
split-horizon was disabled on the physical interface
R2(config)#do sh ip int s0/0 | i Split
Split horizon is disabled
On R6 I created a new loopback interface using 6.6.6.6/32 and brought it into
the routing process, I'm now seeing the route on R5
R5#show ip route rip | i 6.6.6.6
R 6.6.6.6 [120/2] via 150.100.100.6, 00:00:13, Serial0/0
Next I enabled split horizon on R2's s0/0 and waited for it to timeout on R5
(watching Deadliest Warrior during downtime :)
R2(config)#int s0/0
R2(config-if)#ip split-horizon
R2(config-if)#do sh ip int s0/0 | i Split
Split horizon is enabled
R5#sh ip route rip | i 6.6.6.6
R 6.6.6.6/32 is possibly down,
So by default split-horizon is disabled on physical frame relay interfaces and
RIP routes will be advertised.
What about EIGRP??
I'll use the same scenario by removing RIP and enabling EIGRP in AS 666
R2(config-if)#do sh ip int s0/0 | i Split
Split horizon is disabled
On R5 I never receive any D routes even though split-horizon is clearly
disabled on R2's s0/0
R5#sh ip ro
200.0.0.0/32 is subnetted, 1 subnets
C 200.0.0.5 is directly connected, Loopback0
150.100.0.0/24 is subnetted, 1 subnets
C 150.100.100.0 is directly connected, Serial0/0
Now let's disable split-horizon for EIGRP AS 666 on R2 s0/0
R2(config)#int s0/0
R2(config-if)#no ip split-horizon eigrp 666
R5#sh ip ro eig
D 6.0.0.0/8 [90/41152000] via 150.100.100.2, 00:00:09, Serial0/0
So For RIP split horizon is disabled by default on multipoint interfaces
(including the physical interface) but it is not disabled for EIGRP unless you
do it manually.
I hope this helps Rob :)
- Steve
-----Original Message-----
From: Joe Astorino [mailto:[email protected]]
Sent: Monday, April 26, 2010 4:04 PM
To: Di Bias, Steve; Routt, Rob; [email protected]; CCIE OSL
Subject: Re: [OSL | CCIE_RS] VOD Frame-relay
I would need to run a quick test to validate, but I do not recall split horizon
being disabled by default on physical interfaces at all
A good example would be trying to run RIP. I do not think you would get spoke
routes on the other spoke without disabling it
Sent from my Verizon Wireless BlackBerry
Regards,
Joe Astorino - CCIE #24347
Sr. Technical Instructor - IPexpert
Mailto: [email protected]
Telephone: +1.810.326.1444
Live Assistance, Please visit: www.ipexpert.com/chat
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-----Original Message-----
From: "Di Bias, Steve" <[email protected]>
Date: Mon, 26 Apr 2010 18:46:41
To: Joe Astorino<[email protected]>; Routt, Rob<[email protected]>;
[email protected]<[email protected]>; CCIE
OSL<[email protected]>
Subject: RE: [OSL | CCIE_RS] VOD Frame-relay
Joe is right; EIGRP will still be on by default under a physical frame relay
interface. You can use the "no ip split-horizon eigrp AS#" command on the
interface to disable.
Sorry about that
-Steve
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Joe Astorino
Sent: Monday, April 26, 2010 3:44 PM
To: Routt, Rob; [email protected]; CCIE OSL
Subject: Re: [OSL | CCIE_RS] VOD Frame-relay
You will still need to disable it for EIGRP specifically as well
Sent from my Verizon Wireless BlackBerry
Regards,
Joe Astorino - CCIE #24347
Sr. Technical Instructor - IPexpert
Mailto: [email protected]
Telephone: +1.810.326.1444
Live Assistance, Please visit: www.ipexpert.com/chat
eFax: +1.810.454.0130
IPexpert is a premier provider of Self-Study Workbooks, Video on Demand, Audio
Tools, Online Hardware Rental and Classroom Training for the Cisco CCIE (R&S,
Voice, Security & Service Provider) certification(s) with training locations
throughout the United States, Europe, South Asia and Australia. Be sure to
visit our online communities at www.ipexpert.com/communities and our public
website at www.ipexpert.com
-----Original Message-----
From: "Routt, Rob" <[email protected]>
Date: Mon, 26 Apr 2010 15:24:36
To: ccie_rs<[email protected]>
Subject: [OSL | CCIE_RS] VOD Frame-relay
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