02-10-2010 09:22 PM - edited 03-06-2019 09:40 AM
Hi,
I am currently having Metro Ethernet Connection from service provider, they have provided us primary and backup link to our branches.
they have provided us last mile copper (fast ethernet) and have two VLANS, for that i have created subinterfaces, did same on branches routers as well.
i want to use primary link (e.g fastethernet 0/0.1, ip 1.1.1.1/30) and when it is up i want all traffic go out through this interface. and incase of any problem backup link ( fastethernet 0/0.2, ip 2.2.2.1/30) will be utilized.
i set ospf cost 10 on fastethernet 0/0.2, but still receiving time outs.
please let me know that does ospf cost works with ethernet subinterfaces?
regards
Zafar
02-11-2010 12:09 AM
Hello Zafar,
OSPF cost can be set on a per vlan subinterface basis but you have set a cost = default cost
check with
sh ip ospf interface
if second subinterface needs an higher cost use something like
ip ospf cost 100
Hope to help
Giuseppe
02-11-2010 01:16 AM
Hi Giuseppe,
i have set the following
HO router
--------------
int fastethernet 0/0.1
description *** PRI LINK ***
ip address 1.1.1.1 255.255.255.252
ip ospf cost 1
int fastethernet 0/0.2
description *** PRI LINK ***
ip address 2.2.2.1 255.255.255.252
ip ospf cost 10
branch office router
-----------------------------
int fastethernet 0/0.1
description *** PRI LINK ***
ip address 1.1.1.2 255.255.255.252
ip ospf cost 1
int fastethernet 0/0.2
description *** PRI LINK ***
ip address 2.2.2.2 255.255.255.252
ip ospf cost 10
Branch router is getting routes through interface int fastethernet 0/0.1
but when we ping the host behind branch router, we receive timeouts.
please advice
02-11-2010 01:59 AM
Hi Giuseppe,
i have set the following
HO router
--------------
int fastethernet 0/0.1
description *** PRI LINK ***
ip address 1.1.1.1 255.255.255.252ip ospf cost 1
int fastethernet 0/0.2
description *** PRI LINK ***
ip address 2.2.2.1 255.255.255.252ip ospf cost 10
branch office router
-----------------------------
int fastethernet 0/0.1
description *** PRI LINK ***
ip address 1.1.1.2 255.255.255.252ip ospf cost 1
int fastethernet 0/0.2
description *** PRI LINK ***
ip address 2.2.2.2 255.255.255.252ip ospf cost 10
Branch router is getting routes through interface int fastethernet 0/0.1
but when we ping the host behind branch router, we receive timeouts.
please advice
Hi Zafar,
What is the ospf configuration of branch router and have you configured the lan subnet under router ospf command to enter into ospf protocol.
HTH
Ganesh.H
02-11-2010 03:41 AM
Hi Ganesh,
thanks for your reply.
HO Router ospf configuration
router ospf 1
network 1.1.1.0 0.0.0.3 area 2
network 2.2.2.0 0.0.0.3 area 2
network 10.21.21.0 0.0.0.255 area 0
Branch office
router ospf 1
network 1.1.1.0 0.0.0.3 area 2
network 2.2.2.0 0.0.0.3 area 2
network 10.42.42.0 0.0.0.255 area 2
02-11-2010 10:37 AM
Hello Zafar,
as Ganesh has noted it is important to know if you had changed accordingly costs on the branch router (sub)interfaces or not.
OSPF processes configuration looks like fine and should allow for building OSPF adjacencies.
What are you trying to reach with your tests?
What do you mean with " I still see timeouts"?
if you have excessive traffic on primary link you may want to divert selected traffic flows to secondary path using PBR policy based routing.
It is important to describe your scenario in order to get better help
Hope to help
Giuseppe
02-11-2010 08:59 PM
Hello Giuseppe,
there is no problem with ospf adjancies I get all routes through primary link, when i try to ping the hosts behind the router, i get time outs
like 4 successfull reply and then two timeouts and then again it happens.
let me attach the diagram.
please let me know if you need more details.
02-12-2010 12:13 AM
Hello Zafar,
as written before, are costs manipulated on branch router on subinterfaces in the same way or not?
without this information is difficult to say if your routing is fine or not.
or you can post a sh ip route of the source as seen by branch point of view.
Hope to help
Giuseppe
02-17-2010 09:40 PM
hi Giuseppe,
sorry i got busy in other tasks, one of our ASA got failed :-s and plus storage issues.
I hope you are doing well.
well the answer of your question is YES costs manipulated on branch router on subinterfaces in the same way
i have one more question regarding our ASA 5510 and its AIP SSM 10 which i have posted in "Intrusion Prevention Systems/IDS" section.
regards
zafar
02-17-2010 11:38 PM
I'm not convinced this is anything to do with link costs. I think the main things to consider are:
Kevin Dorrell
Luxembourg
02-18-2010 12:04 AM
Hi Kevin Dorrell
branch router receives route from that subinterface that has lowest ospf cost.
HQ router receives route from that subinterface that has the lowest ospf cost.
default route is branch router's LAN interface that is connected with the switch.
please guide me how to check it.
no congestion.
02-11-2010 09:27 AM
Are you saying you aren't getting ospf adjacencies for the branch routers ??? By timeouts what are you referring to ? If pinging to branch devices verify the default gateway on the branch devices you are trying to ping. Verify any software firewalls are shutoff on the clients you are trying to ping .
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