Hi Matt,
I just did a small test and it seems your deny statement should work as
well.
BGP dampening(with route-map option) applies to only prefix; matched by a
route-map sequence which has both permit and "set dampening" command
applied.
R2#show route-map
route-map test, permit, sequence 5
Match clauses:
ip address (access-lists): 2
Set clauses:
dampening 2 2 2 2
Policy routing matches: 0 packets, 0 bytes
route-map test, deny, sequence 10
Match clauses:
ip address (access-lists): 3
Set clauses:
dampening 10 10 10 10
Policy routing matches: 0 packets, 0 bytes
route-map test, permit, sequence 15
Match clauses:
ip address (access-lists): 4
Set clauses:
dampening 4 4 4 4
Policy routing matches: 0 packets, 0 bytes
route-map test, permit, sequence 20
Match clauses:
ip address (access-lists): 5
Set clauses:
Policy routing matches: 0 packets, 0 bytes
R2#show ip bgp dam
R2#show ip bgp dampening parameters
dampening 2 2 2 2 (route-map test 5)
Half-life time : 2 mins Decay Time : 120 secs
Max suppress penalty: 4 Max suppress time: 2 mins
Suppress penalty : 2 Reuse penalty : 2
dampening 10 10 10 10 (route-map test 10) << "though this is displayed, it
is not in effect due to deny seq."
Half-life time : 10 mins Decay Time : 600 secs
Max suppress penalty: 20 Max suppress time: 10 mins
Suppress penalty : 10 Reuse penalty : 10
dampening 4 4 4 4 (route-map test 15)
Half-life time : 4 mins Decay Time : 240 secs
Max suppress penalty: 8 Max suppress time: 4 mins
Suppress penalty : 4 Reuse penalty : 4
R2#
So, only for prefix matching seq 5 and 15, dampening feature is applied.
Could someone confirm the above behavior which i noticed in gns?
Thanks,
Venkat
On Mon, Mar 8, 2010 at 9:59 AM, Matt Hill <[email protected]> wrote:
> HI Venkat,
>
> This was the route-map which was used for dampening. I did not use
> any route-map to suppress or filter any prefixes.
>
> router bgp x
> bgp dampening route-map xxx
>
> Cheers,
> Matt
>
> CCIE #22386
> CCSI #31207
>
> On 8 March 2010 15:12, venkat <[email protected]> wrote:
> > Hi Matt,
> >
> > Doesn't the deny statement in route-map denies those prefixes from
> > advertisement to neighbor. I haven't tested this, but I believe those
> > deny statement will not allow those matched prefix to get advertised.
> >
> > On 3/8/10, Matt Hill <[email protected]> wrote:
> >> Gday...
> >>
> >> This section asks us to make a route-map and assign various dampening
> >> parameters based on different prefix lengths. ie >/24 do x, /22-23 do
> >> y and <21 do z.
> >>
> >> It also stipulates that certain prefixes must not be dampened at all.
> >>
> >> In the route-map, the "do not dampen ranges" have this in the Proctor
> Guide:
> >>
> >> route-map DAMP permit 10
> >> match ip address prefix-list xxx
> >> route-map DAMP permit 20
> >> match ip address prefix-list yyy
> >> set dampening ... etc
> >>
> >> now... for my answer, I entered:
> >>
> >> route-map DAMP deny 10
> >> match ip address prefix-list xxx
> >> route-map DAMP permit 20
> >> match ip address prefix-list yyy
> >> set dampening etc...
> >>
> >> Now... is there any reason why my deny wont work? I mean I am telling
> >> the router to dampen according to a route-map. If I deny in my
> >> route-map, wont it simply _not_ apply dampening to those prefixes?
> >>
> >> Cheers,
> >> Matt
> >>
> >> CCIE #22386
> >> CCSI #31207
> >> _______________________________________________
> >> For more information regarding industry leading CCIE Lab training,
> please
> >> visit www.ipexpert.com
> >>
> >
> > --
> > Sent from my mobile device
> >
>
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