From: Chan Hong (chan_hong33@yahoo.com)
Date: Thu Dec 27 2007 - 03:34:43 ART
1: inject the bgp route which is suppressed in other router(possibly
suppressed by aggregate + summary-only). Please note that the route-map used
in R1. It is "match ip address prefix" + "match ip route-source" in exist-map.
Using "set ip address" in inject-map. It has no conditional state, just inject
the suppressed prefix when exist-map matched.
eg:
connectivity:
R4(AS640)-------R1(AS610)-------R2(AS620)
There are 2 bgp route, 202.2.4.0/24
& 202.2.200.0/24 in R4 and they are aggregated + summary-only in R4. R1 take
this summary route and apply inject map on this summary route to inject 1 of
the suppressed route, 202.2.4.0/24. R2 will see the summary route and the
route injected by R1.
Original route on R4
202.2.4.0/24
202.2.200.0/24
Summary to 202.1.0.0/16 on R4
r4#sh run | be router bgp
router bgp 640
no
synchronization
bgp log-neighbor-changes
network 202.2.4.0
network
202.2.200.0
aggregate-address 202.2.0.0 255.255.0.0 summary-only
neighbor
155.1.14.1 remote-as 610
no auto-summary
Apply inject map on R1, which
config & route-map shown below
r1#sh run | be router bgp
router bgp 610
no
synchronization
bgp log-neighbor-changes
neighbor 155.1.14.4 remote-as 640
neighbor 155.1.129.2 remote-as 620
bgp inject-map INJECT exist-map EXIST
no
auto-summary
route-map INJECT permit 10
set ip address prefix-list 2
route-map EXIST permit 10
match ip address prefix-list 1
match ip
route-source SOURCE
r1#sh ip pre
ip prefix-list 1: 1 entries
seq 5 permit
202.2.0.0/16
ip prefix-list 2: 1 entries
seq 5 permit 202.2.4.0/24
R1#sh ip
access-list
Standard IP access list SOURCE
10 permit 155.1.14.4 (15
matches)
Result in R2
r2#sh ip bgp
BGP table version is 11, local router ID
is 202.2.2.2
Status codes: s suppressed, d damped, h history, * valid, > best,
i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e -
EGP, ? - incomplete
Network Next Hop Metric LocPrf
Weight Path
*> 202.2.0.0/16 155.1.129.1 0 610
640 i
*> 202.2.4.0 155.1.129.1 0 610 ?
r2#
2: Advertisement Map, check the prefix exist(exist-map) or not(non-exist-map).
When the condition is true, advertise the prefix in the advertise-map. note
that the route-map use access-list but not prefix-list. I tried it on
prefix-list but it is not working. It maybe because of the "deny any" at the
end of access-list.
same connectivity:
R4(AS640)-------R1(AS610)-------R2(AS620)
There are 3 routes on R4, apply
advertise-map on R1. Is the route 202.2.200.0 not exist, advertise the route
202.2.210.0. Else, suppress 202.2.210.0
R4
r4#sh run | be router bgp
router
bgp 640
no synchronization
bgp log-neighbor-changes
network 202.2.4.0
network 202.2.200.0
network 202.2.210.0
neighbor 155.1.14.1 remote-as 610
no auto-summary
R1
router bgp 610
no synchronization
bgp
log-neighbor-changes
neighbor 155.1.14.4 remote-as 640
neighbor 155.1.129.2
remote-as 620
neighbor 155.1.129.2 advertise-map ADV-ADV non-exist-map
ADV-NO-EXIST
no auto-summary
route-map ADV-NO-EXIST permit 10
match ip
address 2
route-map ADV-ADV permit 10
match ip address 1
r1#sh ip
access-lists
Standard IP access list 1
10 permit 202.2.210.0, wildcard
bits 0.0.0.255 (10 matches)
Standard IP access list 2
10 permit
202.2.200.0, wildcard bits 0.0.0.255 (30 matches)
Result in R2 when
202.2.200.0 exist
r2#sh ip bgp
BGP table version is 3, local router ID is
202.2.2.2
Status codes: s suppressed, d damped, h history, * valid, > best, i
- internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e -
EGP, ? - incomplete
Network Next Hop Metric LocPrf
Weight Path
*> 202.2.4.0 155.1.129.1 0 610
640 i
*> 202.2.200.0 155.1.129.1 0 610 640 i
r2#
Result in R2 when 202.2.200.0 not exist.
r4(config)#router bgp 640
r4(config-router)#no network 202.2.200.0
r4(config-router)#
r2#sh ip bgp
BGP
table version is 5, local router ID is 202.2.2.2
Status codes: s suppressed, d
damped, h history, * valid, > best, i - internal,
r RIB-failure,
S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network
Next Hop Metric LocPrf Weight Path
*> 202.2.4.0 155.1.129.1
0 610 640 i
*> 202.2.210.0 155.1.129.1 0 610
640 i
r2#
Regards,
Howard
----- 6l%s-l%s ----
1H%s$H!R abdul muhammed
<abdulmuri@gmail.com>
&,%s$H Cisco certification <ccielab@groupstudy.com>
6G0e$i4A!R 2007 &~ 12$k 27 $i ,P4A%| $W$H 2:09:19
%DCD!G need Help on
Conditional Route-advertisement
Hi,
Please can somebody throw more light on
the following and their differences:
1. BGP inject-map exist-map command.
2.
neighbor x.x.x.x advertise-map exist-map/non-exist-map command in
conditional
route advertisement
what kind of scenario will require 1 or 2 above
Thanks
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