06-13-2003 11:25 AM - edited 03-02-2019 08:08 AM
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I am trying to impliment PSTN dial backup on AUX port to back up the main serial link. The branch router config is as follows;
xxxxxxxxx#sh run
Building configuration...
Current configuration : 1786 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname xxxxxxx
!
aaa new-model
!
!
aaa authentication login default local
aaa authentication ppp default local
aaa session-id common
enable password xxxxxxx
!
username xxxxxxx password 0 xxxxxxx
username xxxxxxx password 0 xxxxxxx
username R3 password 0 cisco
mmi polling-interval 60
no mmi auto-configure
no mmi pvc
mmi snmp-timeout 180
ip subnet-zero
!
!
!
ip audit notify log
ip audit po max-events 100
!
!
!
!
interface Loopback0
ip address 172.16.30.94 255.255.255.252
!
interface FastEthernet0
ip address 172.16.24.254 255.255.255.0
speed auto
no cdp enable
!
interface Serial0
ip address 172.16.31.94 255.255.255.252
encapsulation ppp
shutdown
no cdp enable
!
interface Serial1
no ip address
shutdown
no cdp enable
!
interface Async5
ip address 172.16.29.94 255.255.255.252
encapsulation ppp
no ip route-cache
no ip mroute-cache
dialer in-band
dialer idle-timeout 30
dialer map ip 0.0.0.0 name R3 broadcast 2511
dialer map ip 172.16.29.93 name R3 broadcast 2511
dialer watch-group 8
dialer-group 1
async default routing
async mode interactive
ppp authentication chap
!
interface Dialer1
no ip address
no cdp enable
!
router ospf 1
log-adjacency-changes
area 1 stub no-summary
network 172.16.24.254 0.0.0.0 area 1
network 172.16.30.94 0.0.0.0 area 1
network 172.16.31.94 0.0.0.0 area 1
!
ip classless
ip route 0.0.0.0 0.0.0.0 172.16.29.93 150
no ip http server
ip pim bidir-enable
!
!
dialer watch-list 8 ip 0.0.0.0 0.0.0.0
dialer-list 1 protocol ip permit
no cdp run
!
!
line con 0
line aux 0
modem InOut
modem autoconfigure discovery
transport input all
stopbits 1
speed 115200
flowcontrol hardware
line vty 0 4
password xxxxxxxxx
!
end
xxxxxxxxx#
Problem: Once the main link goes down, the backup link comes up and I can pass the traffice over the backup line ( eg ping).
But, the backup link never stays up: It re-sets and re-dials.
Following is the "debug dialer" output:
2:41:41: As5 DDR: Dialer Watch: resetting call in progress
02:41:41: DDR: Dialer Watch: watch-group = 8
02:41:41: DDR: network 0.0.0.0/0.0.0.0 DOWN,
02:41:41: DDR: primary DOWN
02:41:41: DDR: Dialer Watch: Dial Reason: Secondary of group 8 DOWN
02:41:41: DDR: Dialer Watch: watch-group = 8,
02:41:41: DDR: dialing secondary by dialer string 2511 on As5
02:41:41: As5 DDR: Attempting to dial 2511
02:41:41: CHAT5: Attempting async line dialer script
02:41:41: CHAT5: no matching chat script found for 2511
02:41:41: CHAT5: Dialing using Modem script: d0efault-d0ials0cript & System script: none
02:41:41: CHAT5: process started
02:41:41: CHAT5: Asserting DTR
02:41:41: CHAT5: Chat script d0efault-d0ials0cript started
02:42:04: CHAT5: Chat script d0efault-d0ials0cript finished, status = Success
02:42:06: %LINK-3-UPDOWN: Interface Async5, changed state to up
02:42:06: As5 DDR: Dialer statechange to up
02:42:06: As5 DDR: Dialer Watch: resetting call in progress
02:42:06: As5 DDR: Dialer call has been placed
02:42:08: As5 DDR: dialer protocol up
02:42:09: %LINEPROTO-5-UPDOWN: Line protocol on Interface Async5, changed state to up
02:42:36: As5 DDR: idle timeout
02:42:36: DDR: Dialer Watch: watch-group = 8
02:42:36: DDR: network 0.0.0.0/0.0.0.0 UP,
02:42:36: DDR: primary DOWN
02:43:06: As5 DDR: idle timeout
02:43:06: DDR: Dialer Watch: watch-group = 8
02:43:06: DDR: network 0.0.0.0/0.0.0.0 UP,
02:43:06: DDR: primary DOWN
02:43:36: As5 DDR: idle timeout
02:43:36: DDR: Dialer Watch: watch-group = 8
02:43:36: DDR: network 0.0.0.0/0.0.0.0 UP,
02:43:36: DDR: primary DOWN
02:44:06: As5 DDR: idle timeout
02:44:06: DDR: Dialer Watch: watch-group = 8
02:44:06: DDR: network 0.0.0.0/0.0.0.0 UP,
02:44:06: DDR: primary DOWN
02:44:12: %LINK-5-CHANGED: Interface Async5, changed state to reset
02:44:13: %LINEPROTO-5-UPDOWN: Line protocol on Interface Async5, changed state to down
02:44:13: DDR: Dialer Watch: watch-group = 8
02:44:13: DDR: network 0.0.0.0/0.0.0.0 DOWN,
02:44:13: DDR: primary DOWN
02:44:13: DDR: Dialer Watch: Dial Reason: Primary of group 8 DOWN
02:44:13: DDR: Dialer Watch: watch-group = 8,
02:44:13: DDR: Dialer Watch: No free dialer on As5
02:44:13: DDR: Dialer Watch: watch-group = 8
02:44:13: DDR: network 0.0.0.0/0.0.0.0 DOWN,
02:44:13: DDR: primary DOWN
02:44:13: DDR: Dialer Watch: Dial Reason: Primary of group 8 DOWN
02:44:13: DDR: Dialer Watch: watch-group = 8,
02:44:13: DDR: Dialer Watch: No free dialer on As5
02:44:17: %LINK-3-UPDOWN: Interface Async5, changed state to down
02:44:27: As5 DDR: re-enable timeout
02:44:27: DDR: Dialer Watch: watch-group = 8
02:44:27: DDR: network 0.0.0.0/0.0.0.0 DOWN,
02:44:27: DDR: primary DOWN
02:44:27: As5 DDR: Dialer Watch: resetting call in progress
02:44:27: As5 DDR: Dialer Watch: Check reconnection needed
02:44:27: As5 DDR: Dialer Watch: resetting call in progress
02:44:27: DDR: Dialer Watch: watch-group = 8
02:44:27: DDR: network 0.0.0.0/0.0.0.0 DOWN,
02:44:27: DDR: primary DOWN
02:44:27: DDR: Dialer Watch: Dial Reason: Secondary of group 8 DOWN
02:44:27: DDR: Dialer Watch: watch-group = 8,
02:44:27: DDR: dialing secondary by dialer string 2511 on As5
02:44:27: As5 DDR: Attempting to dial 2511
02:44:27: CHAT5: Attempting async line dialer script
02:44:27: CHAT5: no matching chat script found for 2511
02:44:27: CHAT5: Dialing using Modem script: d0efault-d0ials0cript & System script: none
02:44:27: CHAT5: process started
02:44:27: CHAT5: Asserting DTR
02:44:27: CHAT5: Chat script d0efault-d0ials0cript started
02:44:50: CHAT5: Chat script d0efault-d0ials0cript finished, status = Success
02:44:52: %LINK-3-UPDOWN: Interface Async5, changed state to up
02:44:52: As5 DDR: Dialer statechange to up
02:44:52: As5 DDR: Dialer Watch: resetting call in progress
02:44:52: As5 DDR: Dialer call has been placed
02:44:55: As5 DDR: dialer protocol up
02:44:56: %LINEPROTO-5-UPDOWN: Line protocol on Interface Async5, changed state to up
02:45:22: As5 DDR: idle timeout
02:45:22: DDR: Dialer Watch: watch-group = 8
02:45:22: DDR: network 0.0.0.0/0.0.0.0 UP,
02:45:22: DDR: primary DOWN
02:45:52: As5 DDR: idle timeout
02:45:52: DDR: Dialer Watch: watch-group = 8
02:45:52: DDR: network 0.0.0.0/0.0.0.0 UP,
02:45:52: DDR: primary DOWN
02:46:22: As5 DDR: idle timeout
02:46:22: DDR: Dialer Watch: watch-group = 8
02:46:22: DDR: network 0.0.0.0/0.0.0.0 UP,
02:46:22: DDR: primary DOWN
02:46:52: As5 DDR: idle timeout
02:46:52: DDR: Dialer Watch: watch-group = 8
02:46:52: DDR: network 0.0.0.0/0.0.0.0 UP,
02:46:52: DDR: primary DOWN
02:46:58: %LINK-5-CHANGED: Interface Async5, changed state to reset
02:46:59: %LINEPROTO-5-UPDOWN: Line protocol on Interface Async5, changed state to down
02:46:59: DDR: Dialer Watch: watch-group = 8
02:46:59: DDR: network 0.0.0.0/0.0.0.0 DOWN,
02:46:59: DDR: primary DOWN
02:46:59: DDR: Dialer Watch: Dial Reason: Primary of group 8 DOWN
02:46:59: DDR: Dialer Watch: watch-group = 8,
02:46:59: DDR: Dialer Watch: No free dialer on As5
02:46:59: DDR: Dialer Watch: watch-group = 8
02:46:59: DDR: network 0.0.0.0/0.0.0.0 DOWN,
02:46:59: DDR: primary DOWN
I cannot figure out what is wrong with this debug output. But one thing is sure. That is, this config was woirking fine when I forst configure it. But after few changes, this problem happened.
Any clue to sort this problem out is greately appreciated.
06-13-2003 11:38 AM
I beleive your prblem is idle-timer. Your Async idle time-out is set to only 30 seconds. It is in seconds. Increase it.
Hope this help.
06-13-2003 07:04 PM
I tried with idle timer of 120 secs , still there is no big improvement.
Waht I want to achieve is;
1. The backup link should stay up regardless of the interesting traffic.
2. The link shouild be down if and only if the primary link is up.
What is the best parameter that I can iuse to achieve above ?
06-13-2003 07:25 PM
Your dialer watch looks like it's working ok locally. The idle-timeout parameter specifies how often the dialer watch will look at the watched route to see if it's up or down. You would normally set this fairly low
(30-60 seconds), depending on how often you want the watch to check. It looks like the distant end is hanging up on you, possibly? I would focus there.
Chris M.
06-13-2003 08:00 PM
According to the dialer watch document found at following link:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/dial_c/dcdbakdw.htm,
it says:
4. In the primary link goes down, Dialer Watch is immediately notified by the routing protocol and the secondary link is brought up.
5. Once the secondary link is up, at the expiration of each idle timeout, the primary link is rechecked.
6. If the primary link remains down, the idle timer is indefinitely reset.
7. If the primary link is up, the secondary backup link is disconnected. Additionally, you can set a disable timer to create a delay for the secondary link to disconnect, after the primary link is reestablished.
Therefore, the backup link should remain up irrespective of the dialer idle-timer. The idle timer specifies how often it should check for the wathed route.
As you said, there can be a problem at the remote end. Ther erelevant config portion at the remote end is as folows;
interface Async225
no ip address
encapsulation ppp
no ip route-cache
no ip mroute-cache
dialer in-band
dialer pool-member 2
async default routing
async mode interactive
no peer default ip address
ppp authentication chap
!
interface Dialer2
ip address 172.16.29.93 255.255.255.252
encapsulation ppp
no ip route-cache
no ip mroute-cache
dialer pool 2
dialer remote-name testbranch
dialer-group 1
no peer default ip address
pulse-time 0
ppp authentication chap
!
!
line aux 0
modem InOut
modem autoconfigure discovery
transport input all
autoselect during-login
autoselect ppp
stopbits 1
speed 115200
flowcontrol hardware
!
There I use dialer profiles and have not specified any special timers, so everything should be in default value.
Any idea as to what could go wrong at the remote end ?
06-14-2003 09:39 AM
Hello,
Since you're not using a dialer watch here, you can set the "dialer idle-timeout" to zero. That way this end will never hang up and the remote end will be responsible for hanging up the connection when things return. Is this what you want?
Chris M.
06-16-2003 07:03 AM
As per your previous suggestion , I changed the Dialer Idle timeout at the remote end. It actually solved the problem !
( Though I had many debugs ON at the remote end as well, I vnever saw any clue as to find out that the remote end is actually closing the connection, therefore I never wanted to do any changes there. But after your suggestion, I just wanted to change the parameter at the remote end as well).
Many thanks for great idea !...
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