http://blog.ipexpert.com/2010/03/29/eigrp-ip-default-network-command/

Thanks.I was also reading bryan article  about this issue.

On Tue, Jun 22, 2010 at 11:54 PM, Cristian Nedelcu <
[email protected]> wrote:

> not quiet.. all that it does is to add a static route..
> you have to repeat ip default-network <this time for clasfull network>
> 2.0.0.0 and now the static route si marked as default on local router...to
> distribute you have to redistribute static into eigrp..
>
> like adrian said before..
> ip default-network works only with clasfull network ; if you have that
> classfull network in your routing table thats good..if not, the router
> ensure that you will have a classfull so it create one for you ...so first
> create clasfull natwork so you can mark it as default
>
>
> On Tue, Jun 22, 2010 at 11:31 PM, Adrian Brayton <[email protected]>wrote:
>
>> Ok... Here you go!
>>
>> Let say that you have 2 routers (R1, R2) This doesn't include other
>> interfaces, just enough to give you the idea.
>>
>> inter lo10
>> ip add 2.2.0.0 255.255.0.0
>>
>> R1
>> router eigrp 1
>> no auto
>> network 2.2.0.0 0.0.255.255
>>
>> ip default-network 2.2.0.0
>>
>> When you look at R2s routing table you will see a little "*" indicating
>> that it the default network.
>>
>> R2#sh ip route 2.2.0.0
>>
>> D* 2.2.0.0/16
>>
>> HTHs
>>
>>
>> On Jun 22, 2010, at 4:16 PM, Mustafa Yadav wrote:
>>
>> Hi Adrian,
>>
>> Thanks.You explained very clearly especially for how to create static
>> route and advertise this as a default route.But without adding manuel static
>> route as far as I understood from your mail by using ip defalut-network a
>> static route has to be created automaticly.I was unable to create this
>> static route automaticly.Can it be change relase to releaase?
>>
>> r5#conf t
>> Enter configuration commands, one per line.  End with CNTL/Z.
>> r5(config)#ip de
>> r5(config)#ip def
>> r5(config)#ip default-n
>> r5(config)#ip default-network 9.9.9.9
>> r5(config)#end
>> r5#sh ip route
>> *Mar  2 07:05:22.796: %SYS-5-CONFIG_I: Configured from console by console
>> Codes: C - connected, S - static, 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
>>        E1 - OSPF external type 1, E2 - OSPF external type 2
>>        i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS
>> level-2
>>        ia - IS-IS inter area, * - candidate default, U - per-user static
>> route
>>        o - ODR, P - periodic downloaded static route
>>
>> Gateway of last resort is not set
>>
>>      1.0.0.0/24 is subnetted, 1 subnets
>> D EX    1.1.1.0 [170/2560002816] via 20.0.0.1, 09:28:49, FastEthernet0/0
>>      3.0.0.0/24 is subnetted, 1 subnets
>> D EX    3.3.3.0 [170/2560002816] via 20.0.0.1, 09:28:49, FastEthernet0/0
>>      20.0.0.0/24 is subnetted, 1 subnets
>> C       20.0.0.0 is directly connected, FastEthernet0/0
>>      10.0.0.0/24 is subnetted, 2 subnets
>> D EX    10.1.13.0 [170/2560002816] via 20.0.0.1, 09:28:49, FastEthernet0/0
>> D EX    10.11.11.0 [170/2560002816] via 20.0.0.1, 09:28:49,
>> FastEthernet0/0
>> r5#
>> r5#
>> r5#conf t
>> Enter configuration commands, one per line.  End with CNTL/Z.
>> r5(config)#int lo
>> r5(config)#int loopback 0
>> r5(config-if)#ip add
>> r5(config-if)#ip address
>> *Mar  2 07:05:41.412: %LINEPROTO-5-UPDOWN: Line protocol on Interface
>> Loopback0, changed state to up9.9.9.9 255.255.255.0
>> r5(config-if)#end
>> r5#sh ip route
>> Codes: C - connected, S - static, 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
>>        E1 - OSPF external type 1, E2 - OSPF external type 2
>>        i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS
>> level-2
>>        ia - IS-IS inter area, * - candidate default, U - per-user static
>> route
>>        o - ODR, P - periodic downloaded static route
>>
>> Gateway of last resort is not set
>>
>>      1.0.0.0/24 is subnetted, 1 subnets
>> D EX    1.1.1.0 [170/2560002816] via 20.0.0.1, 09:29:17, FastEthernet0/0
>>      3.0.0.0/24 is subnetted, 1 subnets
>> D EX    3.3.3.0 [170/2560002816] via 20.0.0.1, 09:29:17, FastEthernet0/0
>>      20.0.0.0/24 is subnetted, 1 subnets
>> C       20.0.0.0 is directly connected, FastEthernet0/0
>>      9.0.0.0/24 is subnetted, 1 subnets
>> C       9.9.9.0 is directly connected, Loopback0
>>      10.0.0.0/24 is subnetted, 2 subnets
>> D EX    10.1.13.0 [170/2560002816] via 20.0.0.1, 09:29:17, FastEthernet0/0
>> D EX    10.11.11.0 [170/2560002816] via 20.0.0.1, 09:29:17,
>> FastEthernet0/0
>> r5#
>> *Mar  2 07:05:50.788: %SYS-5-CONFIG_I: Configured from console by console
>>
>>
>> On Tue, Jun 22, 2010 at 10:16 PM, Adrian Daniel Simionov <
>> [email protected]> wrote:
>>
>>> I hope this example will make U understand how to configure this tricky
>>> command:
>>>
>>> I would like to advertise a default route of 9.9.9.99 to every eigrp
>>> router:
>>>
>>> First create a default static route with the classfull network U are
>>> trying to advertise:
>>>
>>> There are two methods for creating this static route:
>>>
>>> One is using the
>>> #ip default-network 9.9.9.9
>>> command
>>> Which will create a static route for you.
>>>
>>> Another method is by creating the static route by yourself.
>>>
>>> BB2#configure terminal
>>> Enter configuration commands, one per line.  End with CNTL/Z.
>>> BB2(config)#ip route 9.0.0.0 255.0.0.0  9.9.9.99
>>> BB2(config)#end
>>> BB2#sh
>>> *Jun 22 21:42:42.851: %SYS-5-CONFIG_I: Configured from console by console
>>> BB2#sh ip route
>>> Codes: L - local, C - connected, S - static, 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
>>>      E1 - OSPF external type 1, E2 - OSPF external type 2
>>>      i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS
>>> level-2
>>>      ia - IS-IS inter area, * - candidate default, U - per-user static
>>> route
>>>      o - ODR, P - periodic downloaded static route, + - replicated route
>>>
>>> Gateway of last resort is not set
>>>
>>>     10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
>>> C        10.0.0.0/24 is directly connected, FastEthernet0/0
>>> L        10.0.0.1/32 is directly connected, FastEthernet0/0
>>> C        10.10.10.0/24 is directly connected, FastEthernet0/0
>>> L        10.10.10.1/32 is directly connected, FastEthernet0/0
>>> BB2#
>>>
>>> As U can see this static route is not in the routing table. Because we
>>> don;t have a connected interface in this subnet. Now let;s add one:
>>>
>>> BB2(config-if)#ip address 9.9.9.9
>>> *Jun 22 21:44:41.251: %LINK-3-UPDOWN: Interface Loopback1, changed state
>>> to up
>>> *Jun 22 21:44:42.251: %LINEPROTO-5-UPDOWN: Line protocol on Interface
>>> Loopback1, changed state to up
>>> BB2(config-if)#ip address 9.9.9.9 255.255.255.0
>>> BB2(config-if)#end
>>> BB2#
>>> *Jun 22 21:44:48.771: %SYS-5-CONFIG_I: Configured from console by console
>>> BB2#sh ip route
>>> Codes: L - local, C - connected, S - static, 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
>>>      E1 - OSPF external type 1, E2 - OSPF external type 2
>>>      i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS
>>> level-2
>>>      ia - IS-IS inter area, * - candidate default, U - per-user static
>>> route
>>>      o - ODR, P - periodic downloaded static route, + - replicated route
>>>
>>> Gateway of last resort is not set
>>>
>>>     9.0.0.0/8 is variably subnetted, 3 subnets, 3 masks
>>> S        9.0.0.0/8 [1/0] via 9.9.9.99
>>> C        9.9.9.0/24 is directly connected, Loopback1
>>> L        9.9.9.9/32 is directly connected, Loopback1
>>>
>>> As U can see, now we have this static route in the routing table. Now
>>> let;s mark this one as a candidate default route:
>>> The following command will ONLY work if we have a static route in the
>>> routing table
>>> (created with another ip default-network command or with ip route
>>> command)
>>> Why? Ask CISCO !
>>>
>>> BB2(config)#ip default-network 9.0.0.0
>>> BB2(config)#end
>>> BB2#sh i
>>> *Jun 22 21:46:03.119: %SYS-5-CONFIG_I: Configured from console by console
>>> BB2#sh ip route
>>> Codes: L - local, C - connected, S - static, 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
>>>      E1 - OSPF external type 1, E2 - OSPF external type 2
>>>      i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS
>>> level-2
>>>      ia - IS-IS inter area, * - candidate default, U - per-user static
>>> route
>>>      o - ODR, P - periodic downloaded static route, + - replicated route
>>>
>>> Gateway of last resort is 9.9.9.99 to network 9.0.0.0
>>>
>>> S*    0.0.0.0/0 [1/0] via 9.9.9.99
>>> *    9.0.0.0/8 is variably subnetted, 3 subnets, 3 masks
>>> S*       9.0.0.0/8 [1/0] via 9.9.9.99
>>> C        9.9.9.0/24 is directly connected, Loopback1
>>> L        9.9.9.9/32 is directly connected, Loopback1
>>>
>>> Now this route is a default route for us, let;s make a check on eigrp
>>> neighbor BB1:
>>>
>>> BB1#sh ip route
>>> Codes: L - local, C - connected, S - static, 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
>>>      E1 - OSPF external type 1, E2 - OSPF external type 2
>>>      i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS
>>> level-2
>>>      ia - IS-IS inter area, * - candidate default, U - per-user static
>>> route
>>>      o - ODR, P - periodic downloaded static route, + - replicated route
>>>
>>> Gateway of last resort is not set
>>>
>>>     10.0.0.0/8 is variably subnetted, 3 subnets, 2 masks
>>> C        10.0.0.0/24 is directly connected, FastEthernet0/0
>>> L        10.0.0.2/32 is directly connected, FastEthernet0/0
>>> D        10.10.10.0/24 [90/30720] via 10.0.0.1, 00:54:29,
>>> FastEthernet0/0
>>>
>>> This router is not having a default candidate yet.
>>> For this to happen, we need to advertise this static route from BB2,
>>> which is a default candidate for BB2 only now, into eigrp, using
>>> redistribute static:
>>>
>>> BB2(config)#router eigrp 1
>>> BB2(config-router)#redistribute static
>>>
>>> And now let's check the routing table on BB1:
>>>
>>> BB1#sh ip route
>>> Codes: L - local, C - connected, S - static, 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
>>>      E1 - OSPF external type 1, E2 - OSPF external type 2
>>>      i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS
>>> level-2
>>>      ia - IS-IS inter area, * - candidate default, U - per-user static
>>> route
>>>      o - ODR, P - periodic downloaded static route, + - replicated route
>>>
>>> Gateway of last resort is not set
>>>
>>> D*EX  9.0.0.0/8 [170/156160] via 10.0.0.1, 00:01:04, FastEthernet0/0
>>>
>>> Voila, this route is here, marked as a default candidate route.
>>>
>>> Hope this clarified everything about the usage of this command.
>>> _______________________________________________
>>> For more information regarding industry leading CCIE Lab training, please
>>> visit www.ipexpert.com
>>>
>>
>> _______________________________________________
>> For more information regarding industry leading CCIE Lab training, please
>> visit www.ipexpert.com
>>
>>
>>
>> _______________________________________________
>> For more information regarding industry leading CCIE Lab training, please
>> visit www.ipexpert.com
>>
>>
>
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