From: SANCHEZ-MONGE,ANTONIO (HP-France,ex2) (antonio.sanchez-monge@hp.com)
Date: Sun Jan 25 2004 - 16:56:11 GMT-3
Hi Joe,
I had tested it and disabling split horizon does not seem to change this
behaviour. IMHO split horizon does not affect the way to process incoming
updates but the decission on what updates have to be sent out of a
particular interface.
You said: R2 will try to advertise its static route to R4 as 10.0.0.0/8.
This is true as long as "network 10.0.0.0" is explicitly configured under
"router rip" in R2. But this is the locally generated auto-summary, not the
one received from R4.
Cheers,
Ato.
-----Original Message-----
From: Joe Chang [mailto:changjoe@earthlink.net]
Sent: domingo, 25 de enero de 2004 21:00
To: SANCHEZ-MONGE,ANTONIO (HP-France,ex2); 'Hossam'
Cc: ccielab@groupstudy.com
Subject: Re: RIPv1 -RIP v2 and Summary to Null - Scenario!
I don't have a lab at hand to test it out, but my guess is that you can get
both 10.0.0.0 routes to show up if you disable split horizon on the FR on
R2. After all, R2 will try to advertise its static route to R4 as
10.0.0.0/8.
----- Original Message -----
From: "SANCHEZ-MONGE,ANTONIO (HP-France,ex2)" <antonio.sanchez-monge@hp.com>
To: "'Hossam'" <sam6626@yahoo.com>
Cc: <ccielab@groupstudy.com>
Sent: Sunday, January 25, 2004 7:24 AM
Subject: RE: RIPv1 -RIP v2 and Summary to Null - Scenario!
> Hi Sam,
>
> Thanks for the post.
>
> The behaviour I have seen is:
>
> If a router receives a summary for a major network (10.0.0.0), and it
> has already more specific subnetworks directly connected, it will
> suppress the summary from the RIPv1 database.
>
> Try adding 10.2.4.1/32 as a loopback address in R2 and you will see
> the
same
> behaviour. Null0 is at the end a "virtual local interface" too.
>
> The idea behind this is: RIPv1 and classful routing protocols in
> general
do
> not support non-contiguous major networks.
>
> Cheers,
> Ato.
>
>
>
> -----Original Message-----
> From: Hossam [mailto:sam6626@yahoo.com]
> Sent: domingo, 25 de enero de 2004 15:10
> To: SANCHEZ-MONGE,ANTONIO (HP-France,ex2)
> Cc: ccielab@groupstudy.com
> Subject: RE: RIPv1 -RIP v2 and Summary to Null - Scenario!
>
>
> Here you are Antonio,
> The outputs you asked for at R2 are below ( before using "ip route
10.2.4.0
> 255.255.252.0 null0") .
>
> Once i use the above command R2 installs the new to-null route, and
> the "10.0.0.0" auto-summary learned form R4 starts to count to 180
> seconds
then
> it goes to the hold and deleted later. See the show rip database below
after
> using the above command at the end of this message.
>
> This happens while R2 is still recieving the 10.0.0.0 route from R4.
> But
for
> some reason it does't update its database.
>
> I hope someone helps!!
>
> Note: I snapshot these outputs while both routers were using RIP ver1
only.
> No ver2 updates were inter send. But same happens with ver2 at R2 as i
said
> in my intial mail.
>
>
> Thanks
> SAM
> _____________________________________________________
> Router 2:
> Router2#sh ip route
> 172.16.0.0/16 is variably subnetted, 8 subnets, 5 masks
> O IA 172.16.136.0/26 [110/782] via 172.16.32.1, 16:40:45, Serial0/0.23
> C 172.16.32.0/29 is directly connected, Serial0/0.23
> O IA 172.16.35.0/30 [110/1562] via 172.16.23.3, 16:40:45, Serial0/0.32
> [110/1562] via 172.16.32.3, 16:40:45, Serial0/0.23
> O IA 172.16.31.0/30 [110/1562] via 172.16.32.1, 16:40:45, Serial0/0.23
> C 172.16.24.0/24 is directly connected, Serial0/0.24
> C 172.16.23.0/24 is directly connected, Serial0/0.32
> O E2 172.16.15.0/28 [110/20] via 172.16.32.1, 16:40:46, Serial0/0.23
> C 172.16.2.0/24 is directly connecte d, Loopback10
> O E2 192.168.26.0/24 [110/20] via 172.16.32.1, 16:40:46, Serial0/0.23
> R 192.168.4.0/24 [120/1] via 172.16.24.4, 00:00:20, Serial0/0.24
> O E2 192.168.5.0/24 [110/20] via 172.16.32.1, 16:40:46, Serial0/0.23
> 10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
> R 10.0.0.0/8 [120/1] via 172.16.24.4, 00:00:21, Serial0/0.24
> O E2 10.2.6.0/23 [110/20] via 172.16.32.1, 16:40:47, Serial0/0.23
> O E2 192.168.6.0/24 [110/20] via 172.16.32.1, 16:40:47, Serial0/0.23 O
> E2 192.168.16.0/24 [110/20] via 172.16.32.1, 16:40:47, Serial0/0.23 O
> E2 192.168.1.0/24 [110/20] via 172.16.32.1, 16:40:47, Serial0/0.23
> C 192.168.2.0/24 is directly connected, Loopback20
> O E2 192.168.3.0/24 [110/20] via 172.16.23.3, 16:40:47, Serial0/0.32
> [110/20] via 172.16.32.3, 16:40:47, Serial0/0.23
> Router2# Router2#
> Router2#sh ip rip da
> 0.0.0.0/0 auto-summary
> 0.0.0.0/0 redistributed
> [0] via 0.0.0.0,
> 10.0.0.0/8 auto-summary
> 10.0.0.0/8
> [1] via 172.16.24.4, 00:00:07, Serial0/0.24
> 10.2.6.0/23 directly connected, Serial0/0.23
> 172.16.0.0/16 auto-summary
> 172.16.2.0/24 directly connected, Loopback10
> 172.16.15.0/28 redistributed
> [12] via 192.168.1.1,
> 172.16.23.0/24 directly connected, Serial0/0.32
> 172.16.24.0/24 directly connected, Serial0/0.24
> 172.16.31.0/30 redistributed
> [12] via 192.168.1.1,
> 172.16.32.0/29 directly connected, Serial0/0.23
> 172.16.35.0/30 redistributed
> [12] via 192.168.3.3,
> [12] via 192.168.3.3,
> 172.16.136.0/26 redistributed
> [12] via 192.168.1.1,
> 192.168.1.0/24 auto-summary
> 192.168.1.0/24 redistributed
> [12] via 192.168.1.1,
> 192.168.3.0/24 auto-summary
> 192.168.3.0/24 redistributed
> [12] via 192.168.3.3,
> [12] via 192.168.3.3,
> 192.168.4.0/24 auto-summary
> 192.168.4.0/24
> [1] via 172.16.24.4, 00:00:09, Serial0/0.24
> 192.168.5.0/24 auto-summary
> 192.168.5.0/24 redistributed
> [12] via 192.168.5.5,
> 192.168.6.0/24 auto-summary
> 192.168.6.0/24 redistributed
> [12] via 192.168.26.6,
> 192.168.16.0/24 auto-summary
> 192.168.16.0/24 redistributed
> [12] via 192.168.26.6,
> 192.168.26.0/24 auto-summary
> 192.168.26.0/24 redistributed
> [12] via 192.168.26.6,
> ______________________________________________________
>
> Router 4:
> Router4#sh ip route
>
> 172.16.0.0/24 is subnetted, 3 subnets
> C 172.16.24.0 is directly connected, Serial0/0
> R 172.16.23.0 [120/1] via 172.16.24.2, 00:00:19, Serial0/0
> R 172.16.2.0 [120/1] via 172.16.24.2, 00:00:19, Serial0/0
> R 192.168.26.0/24 [120/12] via 172.16.24.2, 00:00:19, Serial0/0
> C 192.168.4.0/24 is directly connected, Loopback10
> R 192.168.5.0/24 [120/12] via 172.16.24.2, 00:00:19, Serial0/0
> 10.0.0.0/22 is subnetted, 1 subnets
> C 10.1.4.0 is directly connected, FastEthernet0/0
> R 192.168.6.0/24 [120/12] via 172.16.24.2, 00:00:20, Serial0/0
> R 192.168.16.0/24 [120/12] via 172.16.24.2, 00:00:20, Serial0/0
> R 192.168.1.0/24 [120/12] via 172.16.24.2, 00:00:20, Serial0/0
> R 192.168.3.0/24 [120/12] via 172.16.24.2, 00:00:20, Serial0/0
> R* 0.0.0.0/0 [120/1] via 172.16.24.2, 00:00:06, Serial0/0
>
> Router4#Sh ip rip da
> 0.0.0.0/0 auto-summary
> 0.0.0.0/0
> [1] via 172.16.24.2, 00:00:13, Serial0/0
> 10.0.0.0/8 auto-summary
> 10.1.4.0/22 directly connected, FastEthernet0/0
> 172.16.0.0/16 auto-summary
> 172.16.2.0/24
> [1] via 172.16.24.2, 00:00:13, Serial0/0
> 172.16.23.0/24
> [1] via 172.16.24.2, 00:00:13, Serial0/0
> 172.16.24.0/24 directly connected, Serial0/0
> 192.168.1.0/24 auto-summary
> 192.168.1.0/24
> [12] via 172.16.24.2, 00:00:13, Serial0/0
> 192.168.3.0/24 auto-summary
> 192.168.3.0/24
> [12] via 172.16.24.2, 00:00:13, Serial0/0
> 192.168.4.0/24 auto-summary
> 192.168.4.0/24 directly connected, Loopback10
> 192.168.5.0/24 auto-summary
> 192.168.5.0/24
> [12] via 172.16.24.2, 00:00:13, Serial0/0
> 192.168.6.0/24 auto-summary
> 192.168.6.0/24
> [12] via 172.16.24.2, 00:00:14, Serial0/0
> 192.168.16.0/24 auto-summary
> 192.168.16.0/24
> [12] via 172.16.24.2, 00:00:14, Serial0/0
> 192.168.26.0/24 auto-summary
> 192.168.26.0/24
> [12] via 172.16.24.2, 00:00:14, Serial0/0
> Router4# _________________________________________________________
>
> Router 2 after using the ip route command (part of the output to avoid
> repetation)
>
> Router2(config)#do sh ip rip da
> 0.0.0.0/0 auto-summary
> 0.0.0.0/0 redistributed
> [0] via 0.0.0.0,
> 10.0.0.0/8 auto-summary
> 10.0.0.0/8 is possibly down
> 10.2.6.0/23 directly connected, Serial0/0.23
> 172.16.0.0/16 auto-summary
> 172.16.2.0/24 directly connected, Loopback10
> 172.16.15.0/28 redistributed
> [12] via 192.168.1.1,
> 172.16.23.0/24 directly connected, Serial0/0.32
> 172.16.24.0/24 directly connected, Serial0/0.24
> 172.16.31.0/30 redistributed
> [12] via 192.168.1.1,
> 172.16.32.0/29 directly connected, Serial0/0.23
> 172.16.35.0/30 redistributed
>
>
> Thanks
> SAM
>
>
> From: "SANCHEZ-MONGE,ANTONIO (HP-France,ex2)"
<antonio.sanchez-monge@hp.com>
> Add to Address Book
> To: "'Hossam'" <sam6626@yahoo.com>
> Subject: RE: RIPv1 -RIP v2 and Summary to Null - Scenario!
> Date: Sun, 25 Jan 2004 12:05:39 +0100
>
> Hi Hossam,
> Could you post show ip route and show ip rip database for R2 and R4 in
> the list?
> Cheers,
> Ato.
>
> -----Original Message-----
> From: Hossam [mailto:sam6626@yahoo.com]
> Sent: domingo, 25 de enero de 2004 0:49
> To: ccielab@groupstudy.com
> Subject: RIPv1 -RIP v2 and Summary to Null - Scenario!
>
> Team,
> Assume we have R4 and R2. R4 MUST run RIP v.1
>
> R4 is conneceted to the backbone via Ethernet with subnet 10.1.4.0/22.
>
> R2 is connected to the rest of the network form one side. And to R4
> via a FR link (with Split horizon on both sides.) from the other side.
>
> Diagram:
>
> ALL ROUTERS -- R2 --- FR --------R4 ---- BB1(10.1.4.4)
>
>
> R2 is runnning Rv2 with "no auto summary". R2 is recieving v1 updates
> from R4. R2 is sending v1 and V2 updates to R4.
>
> Due to auto summary on R4, i am getting 10.0.0.0/8 in R2 RIP v.2
> database. Having this route on R2 is a must for the rest of the
> routers (connected to
> R2) to reach the backbone.
>
> For the scenario requirment i need to configure a static summary route
> to "10.2.4.0 255.255.252.0" to a null interface on R2.
> Strangly, Once i configure this summary to null on R2, the classful
> summary
> of 10.0.0.0 learnt from R4 is deleted form R2 Routing table!!!
> Using debug i know that R4 is still sending the 10.0.0.0 to R2. R2
> Recieves
> the route but it stops updating it database with it??
> Does anyone know an explanation??
> Note: Router 2 is runnig IOS 12.2
> Thanks
> SAM
>
>
>
>
>
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