From: Horszczaruk Krzysztof (Krzysztof.Horszczaruk@xxxxxxxxxxxxx)
Date: Tue Aug 13 2002 - 03:26:52 GMT-3
please understand, that summarization in OSPF is one thing.
and redistribution is an another one.
you can suppress this null 0 summary route, and another ospf routers will se th
e summary pointing to right interface (not null 0).
but if you want to redistribute ON THE SAME ROUTER ... see below :-)
>>>-----Original Message-----
>>>From: ong yong keat [mailto:ongyongk@yahoo.com]
>>>Sent: Tuesday, August 13, 2002 3:35 AM
>>>To: ccielab@groupstudy.com
>>>Subject: RE: 'no discard-route external' issue
>>>
>>>
>>>Cisco OSPF Design Guide
>>>(www.cisco.com/warp/public/104/3.html#12.0) seems
>>>to imply that the discard route can be removed w/o affecting
>>>summarization.
>>>
>>>if that's not the case then doesn't 'no discard-route [internal |
>>>external]' defeat the purpose of 'area range' and 'summary-address'?
>>>
>>>regards,
>>>ong
>>>
>>> --- Horszczaruk Krzysztof wrote:
>>>> the behaviour is absolutely correct.
>>>>
>>>> you can redistribute just what is in routing table. you can NOT
>>>> redistribute OSPF topology table.
>>>> you have to have summary route in ospf routing table in order to
>>>> redistribute it to any other protocol.
>>>>
>>>> regards - Krzysztof.
>>>>
>>>>
>>>>>-----Original Message-----
>>>>>From: ong yong keat [mailto:ongyongk@yahoo.com]
>>>>>Subject: 'no discard-route external' issue
>>>>>
>>>>>I tried the 2nd OSPF process solution for the OSPF to IGRP
>>>>>mask problem, and it works fine until I try to remove the
>>>>>OSPF-generated static summary to Null0 with
>>>>>'no discard-route external'.
>>>>>
>>>>>With the Null0 summary gone from r1's routing table, it also
>>>>>stopped advertising the /24 summary into IGRP (r2).
>>>>>
>>>>>Is that the correct behaviour? If so, then this solution
>>>>>would not work if OSPF-generated static summaries to Null0
>>>>>are not allowed...
>>>>>
>>>>>
>>>>> r2 [12.1(5)T5]
>>>>> |
>>>>> | IGRP 135.4.56.0 /24
>>>>> |
>>>>> r1 [12.2(1)]
>>>>> |
>>>>> | OSPF 135.4.34.0 /29
>>>>> |
>>>>>
>>>>>
>>>>>r1 config
>>>>>---------
>>>>>router ospf 1
>>>>> redistribute igrp 1 subnets
>>>>> network 135.4.34.1 0.0.0.0 area 1
>>>>>!
>>>>>router ospf 2
>>>>> summary-address 135.4.34.0 255.255.255.0
>>>>> redistribute ospf 1 subnets
>>>>>!
>>>>>router igrp 1
>>>>> redistribute ospf 1 metric 1000 100 200 100 1500
>>>>> redistribute ospf 2 metric 1000 100 200 100 1500
>>>>> network 135.4.0.0
>>>>>
>>>>>r1 routing table
>>>>>----------------
>>>>>O 135.4.34.0/24 is a summary, 00:00:30, Null0
>>>>>C 135.4.34.0/29 is directly connected, FastEthernet0/1
>>>>>C 135.4.56.0/24 is directly connected, FastEthernet0/0
>>>>>
>>>>>r2 routing table
>>>>>----------------
>>>>>I 135.4.34.0 [100/10110] via 135.4.56.1, 00:00:00,
>>>>>FastEthernet0/0
>>>>>C 135.4.56.0 is directly connected, FastEthernet0/0
>>>>>
>>>>>r1(config-router)#router ospf 2
>>>>>r1(config-router)#no discard-route external
>>>>>
>>>>>r1 routing table
>>>>>----------------
>>>>>C 135.4.34.0/29 is directly connected, FastEthernet0/1
>>>>>C 135.4.56.0/24 is directly connected, FastEthernet0/0
>>>>>
>>>>>r2 routing table
>>>>>----------------
>>>>>C 135.4.56.0 is directly connected, FastEthernet0/0
>>>
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