Hello,
we have primary MPLS link and backup ISDN on our Cisco 1921 routers, i have noticed that logs show ISDN link keeps going up, and then down after a couple of seconds. I dont see any reason for this happening since our primary link seems to be working fine. Any ideas? Im pasting relevant information below, thank you for reading.
....
Nov 27 13:32:49: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0/0/0, TEI 86 changed to down
Nov 27 13:36:28: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0/0/0, TEI 87 changed to up
Nov 27 13:36:43: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0/0/0, TEI 87 changed to down
Nov 27 13:39:06: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0/0/0, TEI 88 changed to up
Nov 27 13:39:21: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0/0/0, TEI 88 changed to down
Nov 27 13:46:16: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0/0/0, TEI 89 changed to up
Nov 27 13:46:31: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0/0/0, TEI 89 changed to down
Nov 27 13:56:13: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0/0/0, TEI 90 changed to up
Nov 27 13:56:28: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0/0/0, TEI 90 changed to down
Nov 27 13:59:40: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0/0/0, TEI 91 changed to up
Nov 27 13:59:55: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0/0/0, TEI 91 changed to down
Nov 27 14:07:51: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0/0/0, TEI 92 changed to up
...
????#sh isdn status
Global ISDN Switchtype = basic-net3
ISDN BRI0/0/0 interface
dsl 0, interface ISDN Switchtype = basic-net3
Layer 1 Status:
ACTIVE
Layer 2 Status:
TEI = 72, Ces = 1, SAPI = 0, State = TEI_ASSIGNED
Layer 3 Status:
0 Active Layer 3 Call(s)
Active dsl 0 CCBs = 0
The Free Channel Mask: 0x80000003
Total Allocated ISDN CCBs = 0
.....
interface BRI0/0/0
no ip address
encapsulation ppp
dialer pool-member 1
isdn switch-type basic-net3
isdn point-to-point-setup
ppp authentication chap
no cdp enable
!
interface Dialer1
bandwidth 64
ip address **** 255.255.255.0
ip flow ingress
encapsulation ppp
no ip route-cache cef
no ip route-cache
ip summary-address eigrp **** 255.255.252.0
dialer pool 1
dialer order round-robin
dialer string 03*******
dialer string 03*******
dialer string 03*******
dialer string 03*******
dialer string 03*******
dialer hold-queue 40
dialer load-threshold 220 outbound
dialer-group 1
ppp authentication chap
ppp multilink
fair-queue
no cdp enable
