In the ICND book 9th printing

pg. 280
Example 8-2 show ip route (in regards to RIP-1)
referencing p. 279's diagram Figure 8-34..

I'm confused by the output in Example 8-2, compared to the actual
setup in Figure 8-34

snippet from Example 8-2
.... output deleted
Gateway of last resort is not set

172.16.0.0/24 is subnetted, 1 subnets
C 172.16.1.0 is directly connected, Ethernet0
10.0.0.0/24 is subnetted, 2 subnets
R 10.2.2.0 [120/1] via 10.1.1.2, 00:00:07, Serial2
C 10.1.1.0 is directly connected, Serial2
R 192.168.1.0/24 [120/2] via 10.1.1.2, 00:00:07, Serial2
.... end snippet


Since each router in Figure 8-34 has the:
network 10.0.0.0 command run on it, but has interfaces like
10.1.1.1
10.1.1.2
10.2.2.2
10.2.2.3

Why wouldn't Router A have output for show ip protocols like this...
Does it have something to do with RIP-1 vs. classless?
I don't understand how an address like 10.1.1.1 will work with /24
as the network... is this a typo?

10.0.0.0/8 is subnetted, 2 subnets
R 10.2.2.0 [120/1] via 10.1.1.2, 00:00:07, Serial2
C 10.1.1.0 is directly connected, Serial2


Thanks,

Doug T.

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In article <3DEFB9AF.4080603@blackwizard.net>, myrh@blackwizard.net says...
> In the ICND book 9th printing
> pg. 280
> Example 8-2 show ip route (in regards to RIP-1)
> referencing p. 279's diagram Figure 8-34..
>
> I'm confused by the output in Example 8-2, compared to the actual
> setup in Figure 8-34
>
> snippet from Example 8-2
> ... output deleted
> Gateway of last resort is not set
>
> 172.16.0.0/24 is subnetted, 1 subnets
> C 172.16.1.0 is directly connected, Ethernet0
> 10.0.0.0/24 is subnetted, 2 subnets
> R 10.2.2.0 [120/1] via 10.1.1.2, 00:00:07, Serial2
> C 10.1.1.0 is directly connected, Serial2
> R 192.168.1.0/24 [120/2] via 10.1.1.2, 00:00:07, Serial2
> ... end snippet
>
>
> Since each router in Figure 8-34 has the:
> network 10.0.0.0 command run on it, but has interfaces like
> 10.1.1.1
> 10.1.1.2
> 10.2.2.2
> 10.2.2.3
>
> Why wouldn't Router A have output for show ip protocols like this...
> Does it have something to do with RIP-1 vs. classless?
> I don't understand how an address like 10.1.1.1 will work with /24
> as the network... is this a typo?
>
> 10.0.0.0/8 is subnetted, 2 subnets
> R 10.2.2.0 [120/1] via 10.1.1.2, 00:00:07, Serial2
> C 10.1.1.0 is directly connected, Serial2


Not quite sure what you're asking. 10.x.x.x can be used as /24 w/o a
problem. The problem arises when you have variably subnetted interfaces in
RIP Version 1. When using RIP version 1, the router will assume that
whatever mask you have on an interface is the mask for that network. So if
you have 10.x.x.x /24 on an interface, rip V1 will assume that 10.x.x.x is
all at /24. But if it crosses another major network (172.16.0.0 for
example) then the router will assume your 10.x.x.x. is a /8 network.

--

hsb

"Somehow I imagined this experience would be more rewarding" Calvin
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On Fri, 06 Dec 2002 05:46:31 GMT, Hansang Bae <uonr@alp.ee.pbz> wrote:

>In article <3DEFB9AF.4080603@blackwizard.net>, myrh@blackwizard.net says...
>> In the ICND book 9th printing
>> pg. 280
>> Example 8-2 show ip route (in regards to RIP-1)
>> referencing p. 279's diagram Figure 8-34..
>>
>> I'm confused by the output in Example 8-2, compared to the actual
>> setup in Figure 8-34
>>
>> snippet from Example 8-2
>> ... output deleted
>> Gateway of last resort is not set
>>
>> 172.16.0.0/24 is subnetted, 1 subnets
>> C 172.16.1.0 is directly connected, Ethernet0
>> 10.0.0.0/24 is subnetted, 2 subnets
>> R 10.2.2.0 [120/1] via 10.1.1.2, 00:00:07, Serial2
>> C 10.1.1.0 is directly connected, Serial2
>> R 192.168.1.0/24 [120/2] via 10.1.1.2, 00:00:07, Serial2
>> ... end snippet
>>
>>
>> Since each router in Figure 8-34 has the:
>> network 10.0.0.0 command run on it, but has interfaces like
>> 10.1.1.1
>> 10.1.1.2
>> 10.2.2.2
>> 10.2.2.3
>>
>> Why wouldn't Router A have output for show ip protocols like this...
>> Does it have something to do with RIP-1 vs. classless?
>> I don't understand how an address like 10.1.1.1 will work with /24
>> as the network... is this a typo?
>>
>> 10.0.0.0/8 is subnetted, 2 subnets
>> R 10.2.2.0 [120/1] via 10.1.1.2, 00:00:07, Serial2
>> C 10.1.1.0 is directly connected, Serial2
>
>
>Not quite sure what you're asking. 10.x.x.x can be used as /24 w/o a
>problem. The problem arises when you have variably subnetted interfaces in
>RIP Version 1. When using RIP version 1, the router will assume that
>whatever mask you have on an interface is the mask for that network. So if
>you have 10.x.x.x /24 on an interface, rip V1 will assume that 10.x.x.x is
>all at /24. But if it crosses another major network (172.16.0.0 for
>example) then the router will assume your 10.x.x.x. is a /8 network.

This explains why I program my interfaces as;
E0 - 10.10.0.1
S0 - 10.100.0.1 255.255.0.0
S1 - 10.200.0.1 255.255.0.0
and rip resolves the networks to 10.0.0.0, as though I had used /8.
Millimeter

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