From: Young K. Bae (ybae@cisco.com)
Date: Tue Sep 24 2002 - 21:09:52 GMT-3
Dear experts,
Need your help verifying the solution, since I often have trouble
understanding the instructions:
R5 has two EBGP peers - R2 and R4. R5 has five routes in its BGP table -
192.168.112.0, 192.168.113.0, 192.168.114.0, 192.168.115.0, and
172.109.109.0. All of these are /24 routes. The first objective is for R5
to not advertise 172.109.109.0 to both R2 and R4. The second objective is
for R5 to advertise only an aggregate address to R4, but not to R2, while
not advertising 192.168.112.0/24 to R2.
The exact instruction from the IPExpert Lab#31 reads:
"R5 should not advertise 172.109.109.0 to R2 or R4. R5 should advertise a
single route for the Class C networks to R4. R2 should not have
192.168.112.0 in its BGP or routing tables. Do not use an access-list."
To accomplish this, I placed a distribute-list that blocks 172.109.109.0 for
both neighbors. Then I aggregated four 192.168.11x.0 networks into
192.168.112.0/22. Then I configured an unsupress-map for R2, that denies
192.168.112.0 and permits the rest. From the display of 'show ip bgp' it
appears to be working, but I'd like your feedback.
R2#sh ip bgp
BGP table version is 105, local router ID is 192.168.2.2
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
* 24.24.24.0/24 172.31.52.1 0 5678 4 i
*> 0.0.0.0 0 32768 i
*> 192.168.112.0/22 172.31.52.1 0 5678 i
*> 192.168.113.0 172.31.52.1 0 5678 9 i
*> 192.168.114.0 172.31.52.1 0 5678 9 i
*> 192.168.115.0 172.31.52.1 0 5678 9 i
R2#
R4#sh ip bgp
BGP table version is 79, local router ID is 192.168.4.4
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
*> 24.24.24.0/24 0.0.0.0 0 32768 i
*> 192.168.112.0/22 172.31.100.5 0 5678 i
R4#
R5#sh ip bgp
BGP table version is 13, local router ID is 192.168.5.5
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
* 24.24.24.0/24 172.31.52.2 0 0 12 12 12 i
*> 172.31.100.4 0 0 4 i
*>i172.109.109.0/24 172.31.69.2 0 100 0 9 i
s>i192.168.112.0 172.31.69.2 0 100 0 9 i
*> 192.168.112.0/22 0.0.0.0 32768 i
s>i192.168.113.0 172.31.69.2 0 100 0 9 i
s>i192.168.114.0 172.31.69.2 0 100 0 9 i
s>i192.168.115.0 172.31.69.2 0 100 0 9 i
R5#
R5#sh run | b router bgp
router bgp 5678
no synchronization
bgp log-neighbor-changes
aggregate-address 192.168.112.0 255.255.252.0 summary-only
neighbor IBGP peer-group
neighbor IBGP remote-as 5678
neighbor IBGP update-source Loopback0
neighbor 172.31.52.2 remote-as 12
neighbor 172.31.52.2 distribute-list 17 out <<<<<
neighbor 172.31.52.2 unsuppress-map UNSUP <<<<<
neighbor 172.31.100.4 remote-as 4
neighbor 172.31.100.4 distribute-list 17 out <<<<<
neighbor 192.168.6.6 peer-group IBGP
neighbor 192.168.7.7 peer-group IBGP
!
ip classless
no ip http server
!
access-list 8 permit 192.168.8.8
access-list 17 deny 172.109.109.0 0.0.0.255
access-list 17 permit any
access-list 19 deny 192.168.112.0 <<<<<
access-list 19 permit 192.168.112.0 0.0.3.0 <<<<<
dialer-list 1 protocol ip permit
route-map UNSUP permit 10 <<<<<
match ip address 19
This archive was generated by hypermail 2.1.4 : Mon Oct 07 2002 - 07:44:02 GMT-3