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New Member

about route-map problem

hi netpro:

can you tell me what are their differences when i redistribute route.

a

ip pre test deny x.x.x.x/24

ip pre test per 0.0.0.0/0 le 32

route-map 10 permit 10

match ip add pre test

route-map 10 per 20

b

ip pre test permit x.x.x.x/24

ip pre test deny 0.0.0.0/0 le 32

route-map 10 deny 10

match ip add pre test

route-map 10 per 20

why the config a can not filter net x.x.x.x ?

1 ACCEPTED SOLUTION

Accepted Solutions

Re: about route-map problem

Hi,

route-map are like complex access-lists.

They are "top-down" processed. Each statement is evaluated until a match is found This will also be end of processing.

In your example a) the match statement describes any network except x.x.x.x/24

Thus route-map statement 10 is not applicable. Like in an ACL the router would continue with statement 20, which permits everything. Thus your example a) route-map would permit every network.

In example b) the first match statement matches exactly x.x.x.x/24

Thus route-map statement 10 is applicable, which says "deny". Thus x.x.x.x/24 is filtered. All other networks would be allowed by statement 20.

Hope this helps! Please rate all posts.

Regards, Martin

4 REPLIES

Re: about route-map problem

hi...

one will allow in redistribution and other will deny in redistribution...

in A use route- map with deny keyword but your B seems to be perfect...

regards

Devang

New Member

Re: about route-map problem

Sequence does matter but here in this case , the checking process reaches and hence X.X.X.X/24 gets permitted in 'a'..

HTH

Gaurav

Re: about route-map problem

Hi,

route-map are like complex access-lists.

They are "top-down" processed. Each statement is evaluated until a match is found This will also be end of processing.

In your example a) the match statement describes any network except x.x.x.x/24

Thus route-map statement 10 is not applicable. Like in an ACL the router would continue with statement 20, which permits everything. Thus your example a) route-map would permit every network.

In example b) the first match statement matches exactly x.x.x.x/24

Thus route-map statement 10 is applicable, which says "deny". Thus x.x.x.x/24 is filtered. All other networks would be allowed by statement 20.

Hope this helps! Please rate all posts.

Regards, Martin

New Member

Re: about route-map problem

thank you for a detailed account :}

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