From: ismail el-shalh (ishelh_mdsa@yahoo.com)
Date: Wed Jan 10 2007 - 07:22:28 ART
Hi Folks, I hope you are doing fine
I want to achieve policy routing and link re-routing at the same time , here is my scenario :
R5
| \
| \
| \
R2 -------R6
|
PC
172.16.7.80
The gateway should be R6 (172.16.7.200)
If the traffic sourced from the PC (172.16.7.80), the traffic should pass via the link between R5 and R2
If the link between R2 and R5 fails, the traffic which is sourced from the PC should pass via the link between R5 and R6.
This policy will serve that if any servers on the LAN initiate traffic, they should be routed via the fast link which is between R6 and R5.
But if any normal PC , then the traffic should pass between R5 and R2.
I used policy routing for this to happen, OSPF is configured between R5 and R2 and between R2 and R6. BGP is configured between R5 and R6.
The problem is occurring when I am setting the next hop on R6 to be toward R2, now if the link between R2 and R5 is up, there will be no problem, but if the link fails between R2 and R5, the BGP route will appear on R2 (Since redistribution is configured on R6) and the packet will go back to R6, now because the policy is configured on R6, R6 will return back the traffic toward R2.
A loop will occur!
I will be happy if some one can tell me the right method to achieve my goal.
Here is my configuration for R2, R5 and R6
R6
ip access-list extended ORACLE_TRAFFIC
permit ip host 172.16.7.180 172.16.20.0 0.0.3.255
ip access-list extended TRAFFIC-TOWARD-R5
remark OTHER RAFFIC DESTINED TOWARD R5
permit ip any 172.16.20.0 0.0.3.255
route-map POLICY_ROUTE permit 10
match ip address ORACLE_TRAFFIC
route-map POLICY_ROUTE permit 30
match ip address TRAFFIC-TOWARD-R5
set ip next-hop 172.16.7.253
interface ethernet 0/0
ip address 172.16.7.200 255.255.252.0
ip policy route-map POLICY_ROUTE
interface serial 0
ip address 150.1.1.6 255.255.255.0
router bgp
no synchronization
neighbor 150.1.1.5 remote-as 500
no auto-summary
router ospf 1
router-id 10.10.10.6
log-adjacency-changes
redistribute bgp 64567 metric-type 1 subnets
network 10.10.10.6 0.0.0.0 area 0
network 172.16.7.200 0.0.0.0 area 0
R2
router ospf 1
router-id 10.10.10.6
log-adjacency-changes
redistribute bgp 64567 metric-type 1 subnets
network 10.10.10.6 0.0.0.0 area 0
network 172.16.7.200 0.0.0.0 area 0
interface serial 0
ip address 130.1.90.1 255.255.255.252
interface FastEthernet0/0
ip address 172.16.7.253 255.255.252.0
router ospf 1
router-id 10.10.10.2
network 10.10.10.2 0.0.0.0 area 0
network 172.16.7.253
router bgp
no synchronization
neighbor 150.1.1.6 remote-as 500
no auto-summary
R5
interface Ethernet0/0
ip policy route-map POLICY_ROUTE
interface serial 0
ip address 150.1.1.5 255.255.255.0
interface serial 1
ip address 130.1.90.2 255.255.255.252
0
ip access-list extended ORACLE_TRAFFIC
permit ip any host 172.16.7.180
ip access-list extended OTHER_TRAFFIC
permit ip any
route-map POLICY_ROUTE permit 10
match ip address ORACLE_TRAFFIC
set ip next-hop 150.1.1.6
!
route-map POLICY_ROUTE permit 20
match ip address OTHER_TRAFFIC
set ip next-hop 130.1.90.1
router bgp 500
bgp log-neighbor-changes
redistribute connected metric 1
neighbor 150.1.1.6 remote-as 65000
no auto-summary
router ospf 1
router-id 10.10.10.13
network 10.10.10.13 0.0.0.0 area 2
network 130.1.90.2 0.0.0.0 area 2
network 172.16.23.254 0.0.0.0 area 2
Thanks in advance :)
Ismail
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This archive was generated by hypermail 2.1.4 : Thu Feb 08 2007 - 23:46:56 ART