10-04-2010 11:14 PM - edited 03-04-2019 09:59 AM
Hi,
Have the following setup:
CE with 3 LAN Subs:
ip address 10.1.1.0 255.255.255.0
ip address 10.254.1.0 255.255.255.0
ip address 192.168.1.0 255.255.255.0
And 2 Eth WAN(A+B) connections both running ospf.
We require both WAN links to advertise all 3 LAN subs(So failover works), but need the following scenario:
WAN link A is primary for subnets 10.1.1.0/24 + 10.254.1.0/24
WAN link B is primary for subnet 192.168.1.0/24
But both links need to be able to accept traffic for all 3 subnets(i.e. advertise them to ospf nei), in the event of a wan link failure.
Thought I could do this with route-maps/metrics:
router ospf 31
router-id 10.2.7.6
log-adjacency-changes
redistribute connected subnets route-map wireless_ospf
passive-interface default
no passive-interface FastEthernet0/1
network 10.2.7.4 0.0.0.3 area 31
!
router ospf 32
router-id 10.2.7.2
log-adjacency-changes
redistribute connected subnets route-map eoc_ospf
passive-interface default
no passive-interface FastEthernet0/0/0
network 10.2.7.0 0.0.0.3 area 32
access-list 90 remark WIRELESS_OSPF_SUB_METRICS
access-list 90 permit 192.168.1.0 0.0.0.255
access-list 91 remark EOC_OSPF_SUB_METRICS
access-list 91 permit 10.1.1.0 0.0.0.255
access-list 91 permit 10.254.1.0 0.0.0.255
access-list 92 remark EOC_OSPF_FILTER_SUB
access-list 92 deny 10.2.7.4 0.0.0.3
access-list 93 remark WIRELESS_OSPF_FILTER_SUB
access-list 93 deny 10.2.7.0 0.0.0.3
route-map eoc_ospf permit 10
match ip address 91
set metric 250
!
route-map eoc_ospf permit 20
match ip address 90
!
route-map eoc_ospf permit 30
match ip address 92
!
route-map wireless_ospf permit 10
match ip address 90
set metric 250
!
route-map wireless_ospf permit 20
match ip address 91
!
route-map wireless_ospf permit 30
match ip address 93
But all subnets are preferred via LinkA (Route-map appears to be working, as metric of 250 is applied)
Routing entry for 10.1.1.0/24
Known via "ospf 31", distance 110, metric 20, type extern 2, forward metric 1
Redistributing via bgp 17766
Advertised by bgp 17766 match external 2
Last update from 10.2.7.6 on GigabitEthernet0/1.498, 02:20:54 ago
Routing Descriptor Blocks:
* 10.2.7.6, from 10.2.7.6, 02:20:54 ago, via GigabitEthernet0/1.498
Routing entry for 10.254.1.0/24
Known via "ospf 31", distance 110, metric 20, type extern 2, forward metric 1
Redistributing via bgp 17766
Advertised by bgp 17766 match external 2
Last update from 10.2.7.6 on GigabitEthernet0/1.498, 02:19:54 ago
Routing Descriptor Blocks:
* 10.2.7.6, from 10.2.7.6, 02:19:54 ago, via GigabitEthernet0/1.498
Route metric is 20, traffic share count is 1
Routing entry for 192.168.1.0/24
Known via "ospf 31", distance 110, metric 250, type extern 2, forward metric 1
Redistributing via bgp 17766
Advertised by bgp 17766 match external 2
Last update from 10.2.7.6 on GigabitEthernet0/1.498, 02:19:11 ago
Routing Descriptor Blocks:
* 10.2.7.6, from 10.2.7.6, 02:19:11 ago, via GigabitEthernet0/1.498
Route metric is 250, traffic share count is 1
Any suggestions on how to achieve the behaviour I am after?
Thanks in advance.
Solved! Go to Solution.
10-04-2010 11:40 PM
Sorry didnt payed more attantion
I think that with changing the distance of the backup routes will help you :
router ospf
distance 120
Dan
10-04-2010 11:58 PM
soruce will match the advertising router , if you will set the wildcard to 0.0.0.3 it will match all the source updates from that class , if you will set 0.0.0.0 you will match only the exact IP. That's why i set to wildcard 0.0.0.0
10-04-2010 11:24 PM
Hi ,
redistribute connected subnets route-map wireless_ospf metric-type 1
HTH
10-04-2010 11:31 PM
Thanks - But didn't appear to make any difference(Other than change the type to extern 1 from 2):
Routing entry for 192.168.1.0/24
Known via "ospf 31", distance 110, metric 251, type extern 1
Redistributing via bgp 17766
Advertised by bgp 17766 match external 2
Last update from 10.2.7.6 on GigabitEthernet0/1.498, 00:00:26 ago
Routing Descriptor Blocks:
* 10.2.7.6, from 10.2.7.6, 00:00:26 ago, via GigabitEthernet0/1.498
Route metric is 251, traffic share count is 1
i.e. It was still preferred via ospf 31
Thanks
10-04-2010 11:40 PM
Sorry didnt payed more attantion
I think that with changing the distance of the backup routes will help you :
router ospf
distance 120
Dan
10-04-2010 11:48 PM
Thanks Dan - Just to confirm:
#distance 120 ?
A.B.C.D IP Source address
source address is CE IP?
It then expects wildcard bits - If the previous is CE IP, I assume /30 (As this is the IP+Sub conf on WAN Int)
Thanks,
10-04-2010 11:58 PM
soruce will match the advertising router , if you will set the wildcard to 0.0.0.3 it will match all the source updates from that class , if you will set 0.0.0.0 you will match only the exact IP. That's why i set to wildcard 0.0.0.0
10-05-2010 12:55 AM
Legend!
Thanks - metric is still the same in both /24's, but ospf 32 is now preferred for 192.168.1.0/24? :
Routing entry for 192.168.1.0/24
Known via "ospf 32", distance 110, metric 20, type extern 2, forward metric 1
Redistributing via bgp 17766
Advertised by bgp 17766 match external 2
Last update from 10.2.7.2 on GigabitEthernet0/1.132, 00:00:14 ago
Routing Descriptor Blocks:
* 10.2.7.2, from 10.2.7.2, 00:00:14 ago, via GigabitEthernet0/1.132
Route metric is 20, traffic share count is 1
Compared to:
Routing entry for 10.254.1.0/24
Known via "ospf 31", distance 110, metric 20, type extern 2, forward metric 1
Redistributing via bgp 17766
Advertised by bgp 17766 match external 2
Last update from 10.2.7.6 on GigabitEthernet0/1.498, 00:00:26 ago
Routing Descriptor Blocks:
* 10.2.7.6, from 10.2.7.6, 00:00:26 ago, via GigabitEthernet0/1.498
Route metric is 20, traffic share count is 1
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