Route Summarization & Autosummarization?

DerekAustin:

I think your config on R2 is still old. Look at your RIP config. You still have network 10.0.0.0 in there. Take that out and see what happens. As someone else suggested, sometimes it's good to start fresh because old entries could linger and make troubleshooting difficult.

router rip
 [B]network 10.0.0.0[/B]
 network 172.16.0.0
 network 192.168.1.0

FYI:

I labbed this up and got the same results as Alan. Here's a quick snapshot of my results.

RTR-3620 <--- This router is your R1

172.16.0.0/24 is subnetted, 1 subnets
C 172.16.1.0 is directly connected, Serial1/1
10.0.0.0/24 is subnetted, 2 subnets
C 10.2.1.0 is directly connected, Ethernet0/0
C 10.2.2.0 is directly connected, Ethernet0/1

RTR-2501 <-- This router is your R2

R 10.0.0.0 [120/1] via 172.16.1.1, 00:00:17, Serial0
172.16.0.0 255.255.255.0 is subnetted, 1 subnets
C 172.16.1.0 is directly connected, Serial0

Secondly, with my results and Alan's, if you are still unable to get the same results, then it could be a bug in your virtual simulator.

Okay, when I get home today, I'll remove that 10.0.0.0 and see what happens. Appreciate the help guys! I'll keep ya posted

notgoing2fail wrote: »
DerekAustin:

I think your config on R2 is still old. Look at your RIP config. You still have network 10.0.0.0 in there. Take that out and see what happens. As someone else suggested, sometimes it's good to start fresh because old entries could linger and make troubleshooting difficult.
router rip
 [B]network 10.0.0.0[/B]
 network 172.16.0.0
 network 192.168.1.0

Okay I removed 10.0.0.0 that was lingering there. And I'm still getting this on R2..

Router Con0 is now available

Press RETURN to get started!

Router>en
Router#sho ip route
Codes: C - connected, S - static, I - IGRP, 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
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default
U - per-user static route, o - ODR, P - periodic downloaded static route
T - traffic engineered route

Gateway of last resort is not set

172.16.0.0/24 is subnetted, 1 subnets
C 172.16.1.0 is directly connected, Serial0/0
10.0.0.0/24 is subnetted, 2 subnets
R 10.2.1.0 [120/1] via 172.16.1.1, 20:11:19, Serial0/0
R 10.2.2.0 [120/1] via 172.16.1.1, 20:11:19, Serial0/0
Router#Router#

Are you configuring "your rip networks?"

I"m configuring the 10.2.2.0 & 10.1.1.0 to be advertised by RIP.. Are you? Or are you just configuring 10.0.0.0 ?

Ok, I put 10.2.1.1 and 10.2.2.1 as the addresses for the two ethernet ports, and put 10.2.1.0 and 10.2.2.0 as the networks in the RIP process for Router1, with 192.168.1.0 obviously on the WAN link between them, and on Router2 I get:

Router2#sh ip route
<snip>
R 10.0.0.0/8 [120/1] via 192.168.1.1, 00:00:09, Serial0/0/0
C 192.168.1.0/24 is directly connected, Serial0/0/0

Router2#debug ip rip
#RIP: received v1 update from 192.168.1.1 on Serial0/0/0

10.0.0.0 in 1 hops

And I got the exact same RIP update 6 times now while I've been working on this post.

What are you setting this up on? Notgoing2fail is using real routers (I'm assuming) and I mocked it up in Packet Tracer, simulated 1841 routers running a simulated 12.4 IOS. So I'm wondering about your setup and if you're coming across a bug perhaps.

And for reference, here's the running-config for Router1, which is the one of interest here:

Building configuration...

Current configuration : 663 bytes
!
version 12.4
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Router1
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface FastEthernet0/0
ip address 10.2.1.1 255.255.255.0
duplex auto
speed auto
!
interface FastEthernet0/1
ip address 10.2.2.1 255.255.255.0
duplex auto
speed auto
!
interface Serial0/0/0
ip address 192.168.1.1 255.255.255.0
clock rate 64000
!
interface Serial0/1/0
no ip address
shutdown
!
interface Vlan1
no ip address
shutdown
!
router rip
version 1
network 10.0.0.0
network 192.168.1.0
!
ip classless
!
!
!
!
!
!
!
line con 0
line vty 0 4
login
!
!
!
end

alan2308 wrote: »

Ok, I put 10.2.1.1 and 10.2.2.1 as the addresses for the two ethernet ports, and put 10.2.1.0 and 10.2.2.0 as the networks in the RIP process for Router1, with 192.168.1.0 obviously on the WAN link between them, and on Router2 I get:

Router2#sh ip route
<snip>
R 10.0.0.0/8 [120/1] via 192.168.1.1, 00:00:09, Serial0/0/0
C 192.168.1.0/24 is directly connected, Serial0/0/0

Router2#debug ip rip
#RIP: received v1 update from 192.168.1.1 on Serial0/0/0

10.0.0.0 in 1 hops

And I got the exact same RIP update 6 times now while I've been working on this post.

What are you setting this up on? Notgoing2fail is using real routers (I'm assuming) and I mocked it up in Packet Tracer, simulated 1841 routers running a simulated 12.4 IOS. So I'm wondering about your setup and if you're coming across a bug perhaps.

I'm using Sybex Virtual Lab software. The Virtual Router's are 2600's

alan2308 wrote: »

What are you setting this up on? Notgoing2fail is using real routers (I'm assuming) and I mocked it up in Packet Tracer, simulated 1841 routers running a simulated 12.4 IOS. So I'm wondering about your setup and if you're coming across a bug perhaps.

Yup real routers here.

I see that Derek is using Sybex Simulator? I'm not too familiar with that.

But in any event, it has got to be a bug at this point...

DerekAustin26 wrote: »

I'm using Sybex Virtual Lab software. The Virtual Router's are 2600's

Im wondering if this is what the problem is. Based on your configuration and the debug output, the routers say they're working in RIPv1, but I wonder if they're really doing v2.

Have you tried manually specifying version 1 in the RIP process?

johnwest43

typesh wrote: »

Autosummary is on by default for RIPv2 and EIGRP.

As of 12.2( 8 )t EIGRP auto summarization is disabled by default.

alan2308 wrote: »

router rip
version 1
network 10.0.0.0
network 192.168.1.0
!
ip classless
!

end

Here is the problem. You are advertising network 10.0.0.0 - This isn't "autosummary" because it's just simply advertising what you configured. Autosummary shouldn't require you to summarize it for the router. It should do this automatically. Of course anything you configure under rip, it's gonna advertise.

Try this... Take out network 10.0.0.0 and advertise networks: 10.2.1.0 & 10.2.2.0 and see what happens... Just for grins...

And to answer your question: I haven't specified RIPv1 in the process because RIPv1 is on by default when configuring RIP. You should only have to specify "Version 2", but just for grins, i'll try that anyways.

DerekAustin26 wrote: »

Here is the problem. You are advertising network 10.0.0.0 - This isn't "autosummary" because it's just simply advertising what you configured. Autosummary shouldn't require you to summarize it for the router. It should do this automatically. Of course anything you configure under rip, it's gonna advertise.

Try this... Take out network 10.0.0.0 and advertise networks: 10.2.1.0 & 10.2.2.0 and see what happens... Just for grins...

And to answer your question: I haven't specified RIPv1 in the process because RIPv1 is on by default when configuring RIP. You should only have to specify "Version 2", but just for grins, i'll try that anyways.

Interesting! Now I'm going to have to try this out myself.

My initial config was just like Alan's using "network 10.0.0.0"

But now let me try:

network 10.2.1.0
network 10.2.2.0

chX

DerekAustin26 wrote: »

Here is the problem. You are advertising network 10.0.0.0 - This isn't "autosummary" because it's just simply advertising what you configured. Autosummary shouldn't require you to summarize it for the router. It should do this automatically. Of course anything you configure under rip, it's gonna advertise.

Try this... Take out network 10.0.0.0 and advertise networks: 10.2.1.0 & 10.2.2.0 and see what happens... Just for grins...

And to answer your question: I haven't specified RIPv1 in the process because RIPv1 is on by default when configuring RIP. You should only have to specify "Version 2", but just for grins, i'll try that anyways.

RIP (Version 1 and 2) will "fix it" for you. Regardless of what you enter in the network statements, it will amend it to the classful address in the running config.

I whipped something up in Packet Tracer.

For example:

Router#sh ip int b
FastEthernet0/0 192.168.0.2 YES manual up up
Loopback1 10.0.2.1 YES manual up up
Router#conf t
Router(config)#router rip
Router(config-router)#network 10.0.2.1
Router(config-router)#network 192.168.0.2
Router(config-router)#end
Router#
%SYS-5-CONFIG_I: Configured from console by console
Router#sh run
Building configuration...

Current configuration : 576 bytes
<-- Text removed -->
router rip
network 10.0.0.0
network 192.168.0.0

And version 2:

Router2#sh ip int b
FastEthernet0/0 192.168.0.1 YES manual up up
Loopback1 10.0.1.1 YES manual up up

Router2#conf t
Router2(config)#router rip
Router2(config-router)#version 2
Router2(config-router)#network 192.168.0.1
Router2(config-router)#network 10.0.1.1
Router2(config-router)#end
Router2#
%SYS-5-CONFIG_I: Configured from console by consolesh run
Building configuration...

Current configuration : 585 bytes
<-- Text removed -->
router rip
version 2
network 10.0.0.0
network 192.168.0.0

Now, I set both of those routers to version 2. Here's the sh ip route on each router:

10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
R 10.0.0.0/8 [120/1] via 192.168.0.2, 00:00:00, FastEthernet0/0
C 10.0.1.0/24 is directly connected, Loopback1
192.168.0.0/30 is subnetted, 1 subnets
C 192.168.0.0 is directly connected, FastEthernet0/0

10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
R 10.0.0.0/8 [120/1] via 192.168.0.1, 00:00:02, FastEthernet0/0
C 10.0.2.1/32 is directly connected, Loopback1
192.168.0.0/30 is subnetted, 1 subnets
C 192.168.0.0 is directly connected, FastEthernet0/0

You can see that the routes learned via RIP are summarized at their classful boundaries, ie 10.0.0.0/8.

And when I turn off auto-summary:

Router(config)#router rip
Router(config-router)#no au
Router(config-router)#no auto-summary
Router(config-router)#end

10.0.0.0/8 is variably subnetted, 3 subnets, 3 masks
R 10.0.0.0/8 [120/1] via 192.168.0.2, 00:00:30, FastEthernet0/0
C 10.0.1.0/24 is directly connected, Loopback1
R 10.0.2.1/32 [120/1] via 192.168.0.2, 00:00:04, FastEthernet0/0
192.168.0.0/30 is subnetted, 1 subnets
C 192.168.0.0 is directly connected, FastEthernet0/0

DerekAustin26 wrote: »

Here is the problem. You are advertising network 10.0.0.0 - This isn't "autosummary" because it's just simply advertising what you configured. Autosummary shouldn't require you to summarize it for the router. It should do this automatically. Of course anything you configure under rip, it's gonna advertise.

Try this... Take out network 10.0.0.0 and advertise networks: 10.2.1.0 & 10.2.2.0 and see what happens... Just for grins...

And to answer your question: I haven't specified RIPv1 in the process because RIPv1 is on by default when configuring RIP. You should only have to specify "Version 2", but just for grins, i'll try that anyways.

I did put in 10.2.1.0 and 10.2.2.0. You even quoted my post stating that here.

chX wrote: »

I whipped something up in Packet Tracer.

I think that is the problem. I did mine in PT and notgoing2fail was on real routers, but Derek was using the Sybex simulator. We're thinking that might have a lot to do with his results.

alan2308 wrote: »

I think that is the problem. I did mine in PT and notgoing2fail was on real routers, but Derek was using the Sybex simulator. We're thinking that might have a lot to do with his results.

I'm going to lab this up one more time. And provide my results. After this I'm going to have to conclude that it's just a Sybex bug, if I get the same results.

I don't see any use in spending all this time when the problem could be a virtual simulator.

I think it's always good to make sure that it's not a bug, which is why I'm going to lab it one just one more time.

typesh

johnwest43 wrote: »

As of 12.2( 8 )t EIGRP auto summarization is disabled by default.

Thanks. Didn't know that.

notgoing2fail wrote: »

I'm going to lab this up one more time.

I labbed this up as well using 2501s. Here are my results:

Router 1 Config

!
interface Loopback1
ip address 10.2.1.1 255.255.255.0
!
interface Loopback2
ip address 10.2.2.1 255.255.255.0
!
interface Ethernet0
no ip address
shutdown
!
interface Serial0
ip address 172.16.0.1 255.255.0.0
!
interface Serial1
no ip address
shutdown
!
router rip
network 10.0.0.0
network 172.16.0.0

Router 1's Debug IP Rip Output

Router#debug ip rip
RIP protocol debugging is on
Router#
*Mar 1 00:11:05.803: RIP: sending v1 update to 255.255.255.255 via Loopback1 (10.2.1.1)
*Mar 1 00:11:05.807: RIP: build update entries
*Mar 1 00:11:05.811: subnet 10.2.2.0 metric 1
*Mar 1 00:11:05.811: network 172.16.0.0 metric 1
*Mar 1 00:11:05.815: RIP: sending v1 update to 255.255.255.255 via Loopback2 (10.2.2.1)
*Mar 1 00:11:05.819: RIP: build update entries
*Mar 1 00:11:05.819: subnet 10.2.1.0 metric 1
*Mar 1 00:11:05.823: network 172.16.0.0 metric 1
*Mar 1 00:11:05.827: RIP: sending v1 update to 255.255.255.255 via Serial0 (172.16.0.1)
*Mar 1 00:11:05.831: RIP: build update entries
*Mar 1 00:11:05.831: network 10.0.0.0 metric 1

Router 2 Config

interface Ethernet0
no ip address
shutdown
!
interface Serial0
ip address 172.16.0.2 255.255.0.0
clockrate 64000
!
interface Serial1
no ip address
encapsulation frame-relay
clockrate 64000
frame-relay intf-type dce
frame-relay route 201 interface Serial0 102
!
router rip
network 172.16.0.0

Router 2's Debug IP Rip Output

FR_SWITCH#debug ip rip
RIP protocol debugging is on
FR_SWITCH#
*Mar 1 00:12:53.603: RIP: received v1 update from 172.16.0.1 on Serial0
*Mar 1 00:12:53.607: 10.0.0.0 in 1 hops

Router 2's Routing Table

FR_SWITCH#show ip route
<---omitted--->

Gateway of last resort is not set

C 172.16.0.0/16 is directly connected, Serial0
R 10.0.0.0/8 [120/1] via 172.16.0.1, 00:00:02, Serial0

Edit:

I also tried entering the network statements as 10.2.1.0 and 10.2.2.0. The classfull 10.0.0.0 address will still appear in the config.

See here:

Router(config)#no router rip
Router(config)#
Router(config)#router rip
Router(config-router)#network 10.2.1.0
Router(config-router)#network 10.2.2.0
Router(config-router)#network 172.16.0.0
Router(config-router)#do show run
Building configuration...

Current configuration : 612 bytes
!
version 12.3
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Router
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
ip subnet-zero
!
!
!
!
interface Loopback1
ip address 10.2.1.1 255.255.255.0
!
interface Loopback2
ip address 10.2.2.1 255.255.255.0
!
interface Ethernet0
no ip address
shutdown
!
interface Serial0
ip address 172.16.0.1 255.255.0.0
!
interface Serial1
no ip address
shutdown
!
router rip
network 10.0.0.0
network 172.16.0.0

typesh wrote: »

I labbed this up as well using 2501s. Here are my results:

Thanks! I guess you saved me the hassle of doing the lab, unless you guys really want me to confirm.

Otherwise, I think it's safe at this point that it's a Sybex bug....

chX wrote: »

RIP (Version 1 and 2) will "fix it" for you. Regardless of what you enter in the network statements, it will amend it to the classful address in the running config. [/COLOR]

This is good info. RIPv1 is default. You dont have to enter "version 1" So from your configuration, it looks like RIPv1 is not "autosummarizing" like the book says it does. It says RIPv1 autosummarizes by default.

typesh wrote: »

Thanks. Didn't know that.

I labbed this up as well using 2501s. Here are my results:

Router 1 Config

!
interface Loopback1
ip address 10.2.1.1 255.255.255.0
!
interface Loopback2
ip address 10.2.2.1 255.255.255.0
!
interface Ethernet0
no ip address
shutdown
!
interface Serial0
ip address 172.16.0.1 255.255.0.0
!
interface Serial1
no ip address
shutdown
!
router rip
network 10.0.0.0
network 172.16.0.0

Router 1's Debug IP Rip Output

Router#debug ip rip
RIP protocol debugging is on
Router#
*Mar 1 00:11:05.803: RIP: sending v1 update to 255.255.255.255 via Loopback1 (10.2.1.1)
*Mar 1 00:11:05.807: RIP: build update entries
*Mar 1 00:11:05.811: subnet 10.2.2.0 metric 1
*Mar 1 00:11:05.811: network 172.16.0.0 metric 1
*Mar 1 00:11:05.815: RIP: sending v1 update to 255.255.255.255 via Loopback2 (10.2.2.1)
*Mar 1 00:11:05.819: RIP: build update entries
*Mar 1 00:11:05.819: subnet 10.2.1.0 metric 1
*Mar 1 00:11:05.823: network 172.16.0.0 metric 1
*Mar 1 00:11:05.827: RIP: sending v1 update to 255.255.255.255 via Serial0 (172.16.0.1)
*Mar 1 00:11:05.831: RIP: build update entries
*Mar 1 00:11:05.831: network 10.0.0.0 metric 1

Router 2 Config

interface Ethernet0
no ip address
shutdown
!
interface Serial0
ip address 172.16.0.2 255.255.0.0
clockrate 64000
!
interface Serial1
no ip address
encapsulation frame-relay
clockrate 64000
frame-relay intf-type dce
frame-relay route 201 interface Serial0 102
!
router rip
network 172.16.0.0

Router 2's Debug IP Rip Output

FR_SWITCH#debug ip rip
RIP protocol debugging is on
FR_SWITCH#
*Mar 1 00:12:53.603: RIP: received v1 update from 172.16.0.1 on Serial0
*Mar 1 00:12:53.607: 10.0.0.0 in 1 hops

Router 2's Routing Table

FR_SWITCH#show ip route
<---omitted--->

Gateway of last resort is not set

C 172.16.0.0/16 is directly connected, Serial0
R 10.0.0.0/8 [120/1] via 172.16.0.1, 00:00:02, Serial0

Edit:

I also tried entering the network statements as 10.2.1.0 and 10.2.2.0. The classfull 10.0.0.0 address will still appear in the config.

See here:

Router(config)#no router rip
Router(config)#
Router(config)#router rip
Router(config-router)#network 10.2.1.0
Router(config-router)#network 10.2.2.0
Router(config-router)#network 172.16.0.0
Router(config-router)#do show run
Building configuration...

Current configuration : 612 bytes
!
version 12.3
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Router
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
ip subnet-zero
!
!
!
!
interface Loopback1
ip address 10.2.1.1 255.255.255.0
!
interface Loopback2
ip address 10.2.2.1 255.255.255.0
!
interface Ethernet0
no ip address
shutdown
!
interface Serial0
ip address 172.16.0.1 255.255.0.0
!
interface Serial1
no ip address
shutdown
!
router rip
network 10.0.0.0
network 172.16.0.0

Okay, then my virtual lab software must have a bug. Thanks!

DerekAustin26 wrote: »

Okay, then my virtual lab software must have a bug. Thanks!

It's a good question to ask and worthy of labbing up.

Unfortunately these are the down sides of using simulators. The sims have to be as accurate as possible, that is of utmost importance, otherwise you can really screw up your fundamental understanding of networking.

The upside is that they are cheaper than buying a real lab and not everyone can purchase a lab, but if you can, I always tell people to buy real equipment.

The amount of time we all spent on this, could have been avoided if the sim was accurate...

notgoing2fail wrote: »

It's a good question to ask and worthy of labbing up.

Unfortunately these are the down sides of using simulators. The sims have to be as accurate as possible, that is of utmost importance, otherwise you can really screw up your fundamental understanding of networking.

The upside is that they are cheaper than buying a real lab and not everyone can purchase a lab, but if you can, I always tell people to buy real equipment.

The amount of time we all spent on this, could have been avoided if the sim was accurate...

This is why I'd love to see Packet Tracer made available to everybody. For all its legitimate faults, it doesn't seem to get things blatantly wrong like this.

But either way, I like working though situations like this once in a while. It's a nice conformation that everything that I thought I knew about RIP is indeed correct. Let's just not get carried away with them, OK simulator guys?

alan2308 wrote: »

This is why I'd love to see Packet Tracer made available to everybody. For all its legitimate faults, it doesn't seem to get things blatantly wrong like this.

But either way, I like working though situations like this once in a while. It's a nice conformation that everything that I thought I knew about RIP is indeed correct. Let's just not get carried away with them, OK simulator guys?

lol for every person that talks about getting real equipment, there's someone in the wings waiting to say, "GNS3!!!"....

I think GNS3 is the most accurate though since it uses the actual IOS, we just have to be concerned about the rest of the programming working correctly....

I think too many people learn a topic and move on, only to completely forget everything they learned about RIP, or EIGRP, or STP, VTP etc etc...

So it is good indeed to come back and review these topics....

notgoing2fail wrote: »

lol for every person that talks about getting real equipment, there's someone in the wings waiting to say, "GNS3!!!"....

I think GNS3 is the most accurate though since it uses the actual IOS, we just have to be concerned about the rest of the programming working correctly....

I think too many people learn a topic and move on, only to completely forget everything they learned about RIP, or EIGRP, or STP, VTP etc etc...

So it is good indeed to come back and review these topics....

True, but for someone who's just getting started, GNS3 can be a bit intimidating.

Thanks alot guys! I'm gonna buy me a real cisco kit just because of this problem. I appreciate your help!