05-15-2007 11:28 PM - edited 03-03-2019 05:00 PM
Hello! I have 3 routers. 2 of them are connected over frame relay and third router is used for backup. All 3 using eigrp and backup router is using static floating route to make backup. The problem is that ISDN stay connected when frame relay become up.
05-15-2007 11:54 PM
Hello,
Can you post the config and a diagram? One of the possible reasons is the interesting traffic definied by the dialer-list includes the routing protocol traffic so the eigrp hellos will keep the ISDN active.
Hope it helps,
Krisztian
05-16-2007 02:08 AM
Well The interesting traffic exclude eigrp updates
Here is the acccess list for dialer-group
access-list 115 deny eigrp any any
access-list 115 permit ip any any
The thing is that isdn backup is not on the same router where is primary link. It seems that backup router does not get the eigrp update about new primary route.
05-16-2007 02:24 AM
I don't think that the problem is that the backup router is notified about the primary route, because if there is no traffic through it there is no need for the ISDN to stuck. The ISDN will go down after the idle timeout. There must be some traffic which keeps it active. A config would be helpful together with show ip route output. The reason why the primary route is not installed with eigrp is might be the floating static route metric is less than 90 or 170 (depends how the prefix is annonced through eigrp). So the floating static will have higher preference over eigrp route, but if the isdn goes down the eigrp route should be put in the routing table.
05-16-2007 03:07 AM
Hi ,
can you paste the config of the 3'rd router...
The following link is very useful where isdn is used backup for eirgp links...
http://www.cisco.com/en/US/tech/tk713/tk237/technologies_configuration_example09186a00800a3b77.shtml
Thanks,
Satish
05-16-2007 10:26 PM
Here is the configuration .....
BACKUP ROUTER
interface BRI0
ip address XXXXXXX
encapsulation ppp
no ip mroute-cache
dialer idle-timeout 180
dialer map ip REMOTEIP name REMOTE broadcast NUMBER
dialer load-threshold 5 either
dialer-group 1
isdn switch-type basic-net3
ppp authentication chap
ppp multilink
router eigrp 20
redistribute static
network XXXXXX LANS
network XXXXXX WANS (include ISDN and FRAME RELAY)
no auto-summary
no eigrp log-neighbor-changes
ip route REMOTE LAN 200
dialer-list 1 protocol ip list 115
access-list 115 deny eigrp any any
access-list 115 permit ip any any
REMOTE ROUTER
interface BRI0
ip address XXXXXXX
encapsulation ppp
no ip mroute-cache
dialer idle-timeout 180
dialer map ip BACKUPIP name BACKUP broadcast
dialer load-threshold 5 either
dialer-group 1
isdn switch-type basic-net3
ppp authentication chap
ppp multilink
router eigrp 20
network XXXXXX LANS
network XXXXXX WANS (include ISDN and FRAME RELAY)
no auto-summary
no eigrp log-neighbor-changes
ip route CENTRAL LAN 200
access-list 116 deny eigrp any any
access-list 116 permit ip any any
dialer-list 1 protocol ip list 116
05-16-2007 11:41 PM
Which router is the default gateway for the hosts on the central LAN? If you can post the whole config of the 3 routers that would be fine.
Let's try to remove the network XXXXXX WANS (include ISDN and FRAME RELAY) from the backup router and enable eigrp for only to the FR link. You have static route in both side for the LAN's so no need to run eigrp through the ISDN.
05-16-2007 11:53 PM
It is little complicated.....I use route summarization on wans and ISDNS with one B class and remote and local LANS other B class.
05-17-2007 12:12 AM
How is your LAN connected on the central site to the two routers. Which router is the default gateway. A full config from both routers would be still helpful. I think it is a routing issue, because after the ISDN brought up the traffic is still goes through it even if the primary link will come up. Let's check the routing first.
05-17-2007 02:34 AM
You have example with pseudo IP
....just example
so conf is
ROUTER2
interface eth0
ip address 192.168.100.2/24
interface BRI0
ip address 192.168.4.1/24
encapsulation ppp
no ip mroute-cache
dialer idle-timeout 180
dialer map ip 192.168.4.2 name REMOTE broadcast NUMBER
dialer load-threshold 5 either
dialer-group 1
isdn switch-type basic-net3
ppp authentication chap
ppp multilink
router eigrp 20
redistribute static
network 192.168.0.0
no auto-summary
no eigrp log-neighbor-changes
ip route 192.168.2.0 255.255.255.0 200
ip route 0.0.0.0 0.0.0.0 192.168.1.1
dialer-list 1 protocol ip list 115
access-list 115 deny eigrp any any
access-list 115 permit ip any any
ROUTER3
interface etho
IP address 192.168.2.1/24
int ser0
ip address 192.168.3.2
...
interface BRI0
ip address 192.168.4.2/24
encapsulation ppp
no ip mroute-cache
dialer idle-timeout 180
dialer map ip 192.168.4.1 name BACKUP broadcast
dialer load-threshold 5 either
dialer-group 1
isdn switch-type basic-net3
ppp authentication chap
ppp multilink
router eigrp 20
network 192.168.0.0
no auto-summary
no eigrp log-neighbor-changes
ip route 192.168.1.0/24 bri0 200
ip route 0.0.0.0 0.0.0.0 192.168.1.1
access-list 116 deny eigrp any any
access-list 116 permit ip any any
dialer-list 1 protocol ip list 116
ROUTER1
interface etho
IP address 192.168.100.3/24
int ser0
ip address 192.168.3.1
...
router eigrp 20
network 192.168.0.0
no auto-summary
no eigrp log-neighbor-changes
ip route 0.0.0.0 0.0.0.0 192.168.1.1
ROUTER
eth0
ip address 192.168.100.4/24
eth1
ip address 192.168.1.1/24
router eigrp 20
network 192.168.0.0
This is the logic........of the conf......
See the picture
THANKS
05-17-2007 02:59 AM
If you use the network 192.168.0.0 than eigrp will active only on the interfaces in the 192.168.0.0/24 so it won't cover the 192.168.100.0/24, 192.168.4.0/24 etc. Let's check on which interfaces running the eigrp.
show ip eigrp interfaces
show ip eigrp neighbors
05-17-2007 03:53 AM
No i dont use the 192.168
this is just
an example the 192.168.....in my case is B class adreses
05-17-2007 03:58 AM
Then pls check the show ip route and show ip eigrp topology for the remote LAN prefix on the ROUTER when the ISDN and FR are both up to see which path is preferred by eigrp. You can try to increase the delay under the bri so it will increase the metric of eigrp.
05-17-2007 05:06 AM
how to increase delay under bri and eigrp metric with hold down timmers?
05-17-2007 05:36 AM
As eigrp by default confider only bandwidth and delay of the path you have two choices to influence the metric. The holddown timer is to how long
interfacew bri0
delay 2000
bandwidth 40
If you take a look to the show ip eigrp topology x.x.x.x/y you will see it.
Anyway the hold-down timer is to detect the neighbor is dead and not used for the metric calculation. Hope it helps
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