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970 Views 10 Replies Latest reply: Apr 6, 2012 8:06 PM by Greg, CCNP, JNCIP RSS

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Strange behaviour with route maps in redistribution

Apr 4, 2012 8:37 AM

jean-christophe 298 posts since
Jan 18, 2012

I'm trying to redistribute the subnets from OSPF Area 3 on the right with different metrics into EIGRP AS 1 on the left, using GNS3:


  • 172.16.96.0/25 and 172.16.96.128/25 must not be redistributed on any redistributing routers (RD1/RD14/RD5)
  • 172.16.97.0/26, 172.16.97.64/26 and 172.16.97.128.0/26 must be redistributed only through RD1 with metric 1000 44 255 1 1500
  • 172.16.98.0/27 and 172.16.98.32/27 must be redistributed only through RD14 with metric 10000 4 255 1 1500
  • all other subnets (from other Areas) are redistributed with default metric 1000 1500 255 1 1500

Redistribution, Filtering, PBR and SLA Screenshot.png

The results on R7 are stunning :

 

R7#sh ip rou 172.16.96.0 255.255.252.0 lon

 

...     172.16.0.0/16 is variably subnetted, 21 subnets, 5 masks

 

D EX    172.16.97.128/26 [170/3083264] via 172.30.17.1, 00:40:36, Serial1/0

D EX    172.16.97.64/26 [170/3456000] via 172.30.147.3, 00:40:36, Serial1/2

                                    [170/3456000] via 172.30.17.1, 00:40:36, Serial1/0

D EX    172.16.97.0/26 [170/3083264] via 172.30.17.1, 00:40:36, Serial1/0

D EX    172.16.98.0/27 [170/2170880] via 172.30.147.3, 00:40:36, Serial1/2

D EX    172.16.98.32/27 [170/2170880] via 172.30.147.3, 00:40:36, Serial1/2

 

Everything is OK, except for the subnet 172.16.97.64/26 which:

 

·         should have the same metric as 172.16.97.0/26 and 172.16.97.128/26 ; 3456000 is the default metric here

·         should point to RD1 (172.30.17.1)

 

Here is the running config on RD1:

 

RD1#sh run | beg router

 

router eigrp 1

redistribute ospf 1 route-map rm-Area-3

network 172.30.0.0

default-metric 1000 1500 255 1 1500

no auto-summary

eigrp router-id 1.1.1.1

!...

ip access-list extended acl-96

permit ip 172.16.96.0 0.0.0.255 host 255.255.255.128

ip access-list extended acl-97

permit ip 172.16.97.0 0.0.0.191 host 255.255.255.192

ip access-list extended acl-98

permit ip 172.16.98.0 0.0.0.63 host 255.255.255.224

!       

route-map rm-Area-3 deny 10

match ip address acl-96

!       

route-map rm-Area-3 permit 20

match ip address acl-97

set metric 1000 44 255 1 1500

!       

route-map rm-Area-3 deny 30

match ip address acl-98

!       

route-map rm-Area-3 permit 40

 

Here is the running config on RD14:

 

RD14#sh run | beg router

router eigrp 1

redistribute ospf 14 route-map rm-Area-3

network 172.30.0.0

default-metric 1000 1500 255 1 1500

no auto-summary

eigrp router-id 14.14.14.14

! ...

ip access-list extended acl-96

permit ip 172.16.96.0 0.0.0.255 host 255.255.255.128

ip access-list extended acl-97

permit ip 172.16.97.0 0.0.0.191 host 255.255.255.192

ip access-list extended acl-98

permit ip 172.16.98.0 0.0.0.63 host 255.255.255.224

!

route-map rm-Area-3 deny 10

match ip address acl-96

!

route-map rm-Area-3 deny 20

match ip address acl-97

!

route-map rm-Area-3 permit 30

match ip address acl-98

set metric 10000 4 255 1 1500

!       

route-map rm-Area-3 permit 40

 

Any idea ?

  • Greg, CCNP, JNCIP 171 posts since
    Sep 14, 2011

    In acl-97, your wildcard mask 0.0.0.191 translates to a netmask of 255.255.255.64 (binary .01000000).  That's a discontiguous netmask (unusual).  acl-97 will match 172.16.97.0 and .128, because these are both 0 in the 7th bit.  It will not match 172.16.97.64.

  • rak 55 posts since
    Feb 19, 2012

    hi

    like greg said

    ur wild card mask is not a multiple of two

    hence special attention has to be given

    like greg pointed, the mask wont match the .64

    i guess u will have to use to separate lists one that matches 128 hosts and one that matches the remaing 64

    but

    it was a difficult prob to catch

  • rak 55 posts since
    Feb 19, 2012

    isnt the syntax

    distribute-list route-map name_of_map out protocol_name

     

    btw

    can u please tell me about the destination address u used in the extended access-list

    the part host 255.255.255.248

    what are the exact implications of this??

  • Greg, CCNP, JNCIP 171 posts since
    Sep 14, 2011

    I'm not very experienced w/ EIGRP, so I'm not sure if "distribute-list...out" should be able to modify EIGRP metrics of redistributed routes.  This page shows examples of "distribute-list...in" modifying metrics:

    http://www.cisco.com/en/US/docs/ios/12_3t/12_3t8/feature/guide/gteigrpr.html

     

    I guess it makes sense, if "in" is defined in this context as "into the EIGRP topological database from other protocols".  If that's true, then the reason you see default metrics is because your "distribute-list...out" does not apply to routes being redistributed *into* EIGRP from OSPF.

  • rak 55 posts since
    Feb 19, 2012

    @jean tht was helpful thnks

    the thing is distribute-list with out parameter cannot use route-map s

    we can use the route-map only with the distribute-list in parameter

    surprising isnt it !!

    so while using distribute-list with out we can only use the acl names or no's no route-map

  • Greg, CCNP, JNCIP 171 posts since
    Sep 14, 2011

    I really thought "distribute-list...in" would work, based on what I read in the link I posted.  But I tried it, and I agree - it doesn't seem to work.  Maybe I misunderstood that article, or maybe that article doesn't apply to my IOS version.  Sorry, just trying to help (and learn, myself).

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