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RE: Re-4: Route-Map Logic (Example from networkers 2000) posted 09/29/2003
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Hi
I see expected result. If it match first route-map it did not go to 2nd route map statement.


router bgp 200
 neighbor 150.50.5.68 remote-as 100
 neighbor 150.50.5.68 route-map assign in
!
ip as-path access-list 1 permit _50_
ip as-path access-list 2 permit _75_
!
route-map assign permit 10
 match as-path 1
 set metric 111
!
route-map assign permit 20
 match as-path 2
 set local-preference 222

   Network          Next Hop            Metric LocPrf Weight Path
*> 130.10.10.0/24   150.50.5.68            111             0 100 50 i
*> 130.20.20.0/24   150.50.5.68            111             0 100 50 i
*> 140.10.10.0/24   150.50.5.68              0    222      0 100 75 i
*> 140.20.20.0/24   150.50.5.68              0    222      0 100 75 i
*> 160.10.10.0/24   150.50.5.68            111             0 100 50 75 i
*> 160.20.20.0/24   150.50.5.68            111             0 100 50 75 i


At 07:15 PM 9/28/2003 +0100, Ken.Farrington@xxxxxxxxxxxxxxxxxxx wrote:
Hi Guys,

I am getting a little more confuse now and I hope this e-mail makes sense to
all,  im off for a cigerette and when I come back, this e-mail probably wont
make sense to me :))



if I have

ip as-path access-list 2 permit ^$
!
route-map test permit 10
 match as-path 2
 set metric 333
!
route-map test permit 20
 match as-path 2
 set metric 444
!

It sets the metric on the neighboring BGP router to 333 only for prefixes
that match the as-path criteria.  It does not go onto the next stage of the
route map or if it does, it does not set the metric.
This is inline which what the networkers thing says.


Now if I have this


ip as-path access-list 2 permit ^$
ip as-path access-list 3 permit ^300
!
route-map test permit 10
 match as-path 2
 set metric 333
!
route-map test permit 20
 match as-path 3
 set metric 444
!

It sets the metric to 333 on wotever matches criteria in as-path list 2 and
then goes on to set the metric to 444 for any criteria that meets as-path
list 3.

So can I assume, a prefix can only be matched once in a bgp table (or
routing table) and then exits or goes on the the next line of the route-map?
Which then the particular prefix that has already been matched against once
cannot be matched against again?

Also, if it does go on to the next stage of the route-map, how does it know
not to match again against a ;prefix that has already been matched?

Concept I cant get to grasps with here?

Many thx

Confused Kennyboy

-----Original Message-----
From: Jonathan V Hays [mailto:jhays@xxxxxxxx]
Sent: 28 September 2003 15:49
To: info@xxxxxxxxx; Ken.Farrington@xxxxxxxxxxxxxxxxxxx
Cc: ccielab@xxxxxxxxxxxxxx
Subject: RE: Re-4: Route-Map Logic (Example from networkers 2000)


I was a bit surprised at the results, but I am glad for the knowledge gained.

Thanks! Good information to know.

Jonathan

-----Original Message-----
From: nobody@xxxxxxxxxxxxxx [mailto:nobody@xxxxxxxxxxxxxx] On Behalf Of
info@xxxxxxxxx
Sent: Sunday, September 28, 2003 10:20 AM
To: jhays@xxxxxxxx; Ken.Farrington@xxxxxxxxxxxxxxxxxxx
Cc: ccielab@xxxxxxxxxxxxxx
Subject: Re-4: Route-Map Logic (Example from networkers 2000)


Hi Jonathan,


you're right concerning the def. weight. But if the default is in
effect, it is not displayed with sh ip bgp. The point was, to
demonstrate, that after a permit in a route-map, it is checked against
the other entrys. (Your point 2).

Anyway, I've just changed the route-map:

R2#sh ip bgp
BGP table version is 20, local router ID is 133.1.2.2
Status codes: s suppressed, d damped, h history, * valid, > best, i -
internal
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*>i1.1.1.0/24       133.1.3.3              300    100      0 5001 65001
253 99 100 i
*>i2.2.2.0/24       133.1.3.3              300    100      0 5001 65001
253 99 100 i
*>i3.3.3.0/24       133.1.3.3              300    100      0 5001 65001
253 99 100 i
*>i4.4.4.0/24       133.1.3.3              300    100      0 5001 65001
253 99 100 i
*>i5.5.5.0/24       133.1.3.3              300    100      0 5001 65001
253 99 100 i
*>i6.6.6.0/24       133.1.3.3              300    100      0 5001 65001
253 99 100 i
*>i10.10.1.0/24     133.1.3.3              300    100      0 5001 65001
253 99 100 i
*>i133.1.253.0/24   133.1.3.3              300    100      0 5001 65001
253 99 100 i
*>i144.10.13.0/24   133.1.3.3              444    100      0 5001 i
* i144.10.31.0/24   133.1.3.3              444    100      0 5001 i
   Network          Next Hop            Metric LocPrf Weight Path
* i144.10.35.0/24   133.1.3.3              444    100      0 5001 i
*>i144.10.111.0/24  133.1.3.3              444    100      0 5001 i
*>i150.100.1.0/24   133.1.3.3              444    100      0 5001 i
*>i192.168.161.0    133.1.3.3              300    100      0 5001 65001
253 99 100 i
*>i192.168.167.0    133.1.3.3              300    100      0 5001 65001
253 99 100 i
*>i192.168.170.0    133.1.3.3              300    100      0 5001 65001
253 99 100 i
*>i197.65.7.0       133.1.3.3              300    100      0 5001 65001
253 99 100 i
*>i198.199.199.0    133.1.3.3              300    100      0 5001 65001
253 99 100 i
*>i199.199.198.0    133.1.3.3              300    100      0 5001 65001
253 99 100 i
*>i199.199.199.0    133.1.3.3              300    100      0 5001 65001
253 99 100 i
*>i201.201.201.0    133.1.3.3              444    100      0 5001 i

Q.E.D. ;-)

Cheers
Marcus


-------- Original Message -------- Subject: RE: Re-2: Route-Map Logic (Example from networkers 2000) (28-Sep-2003 16:12) From: jhays@xxxxxxxx To: info@xxxxxxxxx

> I see some flaws in this test.
>
> 1. You are setting local preference to the default, which is 100. So
it
> is not easy to tell if the route-map has actually done anything. You
> would do better to use a non-default value, such as 111.
>
> 2. Please note that each route is filtered by the route-map
> individually. If there are 10 routes, then the route-map is executed
10
> times.  So one route might match on permit 10 while the next route
> matches on permit 20.
>
> To verify that the route-map is exiting on the first match for a given
> route, a better test might be this:
>
> route-map bla01 permit 10
>  match as-path 10
>  set metric 300
> !
> route-map bla01 permit 20
>  match as-path 10
>  set metric 444
>
> If the route-map does NOT exit after permit 10 has set the metric to
> 300, then the final metric will be 444.
>
> HTH,
>
> Jonathan
>
> -----Original Message-----
> From: nobody@xxxxxxxxxxxxxx [mailto:nobody@xxxxxxxxxxxxxx] On Behalf
Of
> info@xxxxxxxxx
> Sent: Sunday, September 28, 2003 8:40 AM
> To: Ken.Farrington@xxxxxxxxxxxxxxxxxxx
> Cc: ccielab@xxxxxxxxxxxxxx
> Subject: Re-2: Route-Map Logic (Example from networkers 2000)
>
>
> Hi Ken,
>
> I've just tested it myself:
> Originating router:
>
> router bgp 1
>  bgp router-id 133.1.5.5
>  bgp log-neighbor-changes
>  neighbor 133.1.2.2 remote-as 1
>  neighbor 133.1.2.2 update-source Loopback0
>  neighbor 133.1.2.2 route-reflector-client
>  neighbor 133.1.2.2 route-map bla01 out
>  neighbor 133.1.3.3 remote-as 5001
>  neighbor 133.1.3.3 ebgp-multihop 2
>  neighbor 133.1.3.3 update-source Loopback0
>  neighbor 133.1.6.6 remote-as 1
>  neighbor 133.1.6.6 update-source Loopback0
>  neighbor 133.1.6.6 route-reflector-client
> !
> ip as-path access-list 10 permit 99
> ip as-path access-list 20 permit ^5001
> !
> !
> route-map bla01 permit 10
>  match as-path 10
>  set metric 300
> !
> route-map bla01 permit 20
>  match as-path 20
>  set local-preference 100
>
> The outcome on the destination router looks like this:
>
> R2#sh ip bgp
> BGP table version is 21, local router ID is 133.1.2.2
> Status codes: s suppressed, d damped, h history, * valid, > best, i -
> internal
> Origin codes: i - IGP, e - EGP, ? - incomplete
>
>    Network          Next Hop            Metric LocPrf Weight Path
> *>i1.1.1.0/24       133.1.3.3              300    100      0 5001
65001
> 253 99 100 i
> *>i2.2.2.0/24       133.1.3.3              300    100      0 5001
65001
> 253 99 100 i
> *>i3.3.3.0/24       133.1.3.3              300    100      0 5001
65001
> 253 99 100 i
> *>i4.4.4.0/24       133.1.3.3              300    100      0 5001
65001
> 253 99 100 i
> *>i5.5.5.0/24       133.1.3.3              300    100      0 5001
65001
> 253 99 100 i
> *>i6.6.6.0/24       133.1.3.3              300    100      0 5001
65001
> 253 99 100 i
> *>i10.10.1.0/24     133.1.3.3              300    100      0 5001
65001
> 253 99 100 i
> *>i133.1.253.0/24   133.1.3.3              300    100      0 5001
65001
> 253 99 100 i
> *>i144.10.13.0/24   133.1.3.3                     100      0 5001 i
> * i144.10.31.0/24   133.1.3.3                     100      0 5001 i
>    Network          Next Hop            Metric LocPrf Weight Path
> *>i144.10.35.0/24   133.1.3.3                     100      0 5001 i
> *>i144.10.111.0/24  133.1.3.3                     100      0 5001 i
> *>i150.100.1.0/24   133.1.3.3                     100      0 5001 i
> *>i192.168.161.0    133.1.3.3              300    100      0 5001
65001
> 253 99 100 i
> *>i192.168.167.0    133.1.3.3              300    100      0 5001
65001
> 253 99 100 i
> *>i192.168.170.0    133.1.3.3              300    100      0 5001
65001
> 253 99 100 i
> *>i197.65.7.0       133.1.3.3              300    100      0 5001
65001
> 253 99 100 i
> *>i198.199.199.0    133.1.3.3              300    100      0 5001
65001
> 253 99 100 i
> *>i199.199.198.0    133.1.3.3              300    100      0 5001
65001
> 253 99 100 i
> *>i199.199.199.0    133.1.3.3              300    100      0 5001
65001
> 253 99 100 i
> *>i201.201.201.0    133.1.3.3                     100      0 5001 i
>
> Thus, the process was running through both route-maps. As per your
> statement, it should only be the MED of 300 for all prefixes
containing
> AS 99...
>
> Hope I could help.
>
> Cheers
> Marcus
>
>
> -------- Original Message --------
> Subject: RE: Route-Map Logic (Example from networkers 2000)
(28-Sep-2003
> 14:12)
> From:    Ken.Farrington@xxxxxxxxxxxxxxxxxxx
> To:      navaid@xxxxxxxxxx
>
> > Yes, they are for different routes.
> >
> > I am just confused then, on how the route-maps work,  so, if you set
> an
> > attrib on prefix A, lets say, then you cant do anything else with a
> route
> > map to that prefix?
> >
> > ?  Im sure there are some "route-map Kings" on this list somewhere?

> >
> > Many thx for the input Navaid :)
> >
> >
> > -----Original Message-----
> > From: navaid@xxxxxxxxxx [mailto:navaid@xxxxxxxxxx]
> > Sent: 28 September 2003 12:55
> > To: Ken.Farrington@xxxxxxxxxxxxxxxxxxx; ccielab@xxxxxxxxxxxxxx
> > Cc: kenfarrington@xxxxxxxxx
> > Subject: Re: Route-Map Logic (Example from networkers 2000)
> >
> >
> > Ken,
> > Are you setting community attribute and next-hop for same route.
> > If it is for different routes. I think it will work because
route-map
> is
> > applied for each route one by one.
> >
> > Navaid.
> >
> >
> > >
> > > From: Ken.Farrington@xxxxxxxxxxxxxxxxxxx
> > > Date: 2003/09/28 Sun AM 06:54:05 EDT
> > > To: ccielab@xxxxxxxxxxxxxx
> > > CC: kenfarrington@xxxxxxxxx
> > > Subject: Route-Map Logic (Example from networkers 2000)
> > >
> > > All,
> > >
> > > I am a little confused about the route-map logic that Cisco use.
> > > In their example from networkers 2000, they say (note the first
line
> in
> > the
> > > table)
> > > that if in your route-map, you have a hit on a permit and set an
> > attribute,
> > > the
> > > route-map will exit?
> > >
> > > +--------------------------------------------------------------+
> > > | ROUTE-MAP |  MATCH CLAUSE/  |  ACCEPT ROUTE and  |   EXIT    |
> > > |  STANZA   |   PREFIX-LIST   |   SET ATTRIBUTE    | ROUTE-MAP |
> > > +-----------+-----------------+--------------------+-----------+
> > > |  Permit   |   Yes/Permit    |        Yes         |    Yes    |
> > > |           |                 |                    |           |
> > > |  Permit   |    No/Deny      |        No          |    No     |
> > > |           |                 |                    |           |
> > > |   Deny    |   Yes/Permit    |        No          |    Yes    |
> > > |           |                 |                    |           |
> > > |   Deny    |    No/Deny      |        No          |    No     |
> > > +-----------+-----------------+--------------------+-----------+
> > >
> > >
> > >
> > > So I have a route map doing two things for BGP.
> > > 1. Setting the next-hop attrib
> > > 2. Setting the community
> > >
> > > But my route map does not exit after the first hit (permit 10) to
> set the
> > > next hop.
> > > It does continue to go onto 20 and set my community.
> > >
> > > Can someone please clarify this for me.
> > >
> > > ****Will it always go onto the next route-map statment if there is
> one?
> > ****
> > >
> > >
> > >
> > > !
> > > ip prefix-list BGP-COMM-LIST seq 5 permit 1.1.1.0/24
> > > ip prefix-list BGP-COMM-LIST seq 10 permit 2.2.2.0/24
> > > !
> > > ip prefix-list BGP-SNH-LIST seq 5 permit 3.3.3.3/32
> > > ip prefix-list BGP-SNH-LIST seq 10 permit 4.4.4.4/32
> > > !
> > > !
> > > route-map BGP-ATTRIB permit 10
> > >  match ip address prefix-list BGP-SNH-LIST
> > >  set ip next-hop 142.220.10.1
> > > !
> > > route-map BGP-ATTRIB permit 20
> > >  match ip address prefix-list BGP-COMM-LIST
> > >  set community local-AS
> > > !
> > > route-map BGP-ATTRIB permit 30
> > > !
> > >
> > >
> > >
> > >
>
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> To: Ken.Farrington@xxxxxxxxxxxxxxxxxxx
> Cc: ccielab@xxxxxxxxxxxxxx
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To: jhays@xxxxxxxx Ken.Farrington@xxxxxxxxxxxxxxxxxxx Cc: ccielab@xxxxxxxxxxxxxx

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