CISCO 3640 PROBLEM?

[84112000]

I have two remote sites A and B. Remote-A has 3640 router and so is my WAN router at Corp office. All are connecting with full T1 point-to-point. Occassionally, Remote-A connection dropped (3-4 times/week). After long diagnostic, I restarted the WAN router and the connection came back. Bellow are the configuration for both router. Please review and thank you for any suggession.
CISCO 3640 – REMOTE_A
version 12.1
no service single-slot-reload-enable
service timestamps debug uptime
service timestamps log uptime
service password-encryption
!
hostname Remote_A
!
logging rate-limit console 10 except errors
enable password xxxxxxxxxxxx
!
ip subnet-zero
!
no ip finger
!
no ip bootp server
call rsvp-sync
!
interface Multilink8
ip address 192.168.32.25 255.255.255.252
ppp chap hostname goods
ppp multilink
multilink-group 8
!
interface FastEthernet0/0
description to CORP HOST
ip address 192.168.33.192 255.255.255.0
duplex auto
speed auto
!
interface Serial0/0
description PTP to CORP HOST
no ip address
encapsulation ppp
no fair-queue
ppp chap hostname goods
ppp multilink
multilink-group 8
!
interface FastEthernet0/1
description CURRENTLY NOT IN USED
no ip address
shutdown
!
interface Serial0/1
description PTP to Irvine
no ip address
encapsulation ppp
no fair-queue
ppp chap hostname goods
ppp multilink
multilink-group 8
!
interface FastEthernet1/0
description CURRENTLY NOT IN USED
no ip address
shutdown
!
interface Serial1/0
description CURRENTLY NOT IN USED
no ip address
shutdown
!
interface FastEthernet1/1
description CURRENTLY NOT IN USED
no ip address
shutdown
!
interface Serial1/1
description CURRENTLY NOT IN USED
no ip address
shutdown
!
no ip classless
ip route 0.0.0.0 0.0.0.0 192.168.32.26
no ip http server
!
snmp-server community public RO
!
dial-peer cor custom
!
line con 0
password xxxxxxxxxxx
login
transport input none
line vty 0 4
password xxxxxxxxxxxxxxx
login
end




CISCO 3640 CORP HOST
Current configuration : 2396 bytes
!
version 12.1
no service single-slot-reload-enable
service timestamps debug uptime
service timestamps log uptime
service password-encryption
!
hostname CORP HOST
!
logging rate-limit console 10 except errors
enable secret xxxxxxxxxxxxxxxxxx
enable password xxxxxxxxxxxxx
!
ip subnet-zero
!
no ip finger
!
no ip bootp server
call rsvp-sync
!
interface Multilink8
ip address 192.168.32.26 255.255.255.252
ppp chap hostname goods
ppp multilink
multilink-group 8
!
interface FastEthernet0/0
description Local Area Network
ip address 192.168.100.192 255.255.255.0
duplex auto
speed auto
!
interface Serial0/0
description PTP to REMOTE_A
no ip address
encapsulation ppp
no fair-queue
service-module t1 clock source internal
service-module t1 timeslots 1-24
ppp chap hostname goods
ppp multilink
multilink-group 8
!
interface FastEthernet0/1
description Local CORP LAN
ip address 192.168.1.192 255.255.240.0 secondary
ip address 192.168.1.254 255.255.240.0
duplex auto
speed auto
!
interface Serial0/1
description PTP to REMOTE_A
no ip address
encapsulation ppp
no fair-queue
service-module t1 clock source internal
service-module t1 timeslots 1-24
ppp chap hostname goods
ppp multilink
multilink-group 8
!
interface FastEthernet1/0
ip address 172.16.1.1 255.255.255.0
duplex auto
speed auto
!
interface Serial1/0
description CURRENTLY NOT IN USED
no ip address
shutdown
!
interface FastEthernet1/1
description CURRENTLY NOT IN USED
no ip address
shutdown
!
interface Serial1/1
description PTP to REMOTE_B
ip address 192.168.32.29 255.255.255.252
encapsulation ppp
no fair-queue
service-module t1 clock source internal
service-module t1 timeslots 1-24
ppp chap hostname goods
!
no ip classless
ip route 0.0.0.0 0.0.0.0 172.16.1.2
ip route 192.168.33.0 255.255.255.0 192.168.32.25
ip route 192.168.34.0 255.255.255.0 192.168.32.30
no ip http server
!
snmp-server community public RO
!
dial-peer cor custom
!
line con 0
password xxxxxxxxxxxxx
login
transport input none
line vty 0 4
password xxxxxxxxxxxx
login
!
end

 

[lui3]

can you do a show log.

you could also use a syslog server to log what is happening when the conneciton drops.

logging host x.x.x.x

Lui3
CCNP,CCDA,A+/Net+
Cisco Wireless Specialization

 

[mtashiro]

I had a similar issue with a pair of 3600 routers some time ago. It was an IOS issue with Multilink.

Another option is to use a routing protocol like EIGRP and get rid of multilink. I use this often and it works great.

 

[84112000]

Thank you both Lui3 and Mtashiro for the info. I do agree with Mtashiro to use EIGRP. Lui3, could you walk me through steps to config and load the syslog? Thanks,

 

[IPEngineer]

I notice that you don't have the T1 channel groups 1-24 configured at one end which would either imply a standard Serial interface using G.703/Serial type Converter for the T1 line or this router is configured as unframed T1.

Rgds
IPEngineer

 

[84112000]

Thank you IPEngineer. I got that and did modified. However, I found out that occassionally the remote have problem with SNMP protocol and the load balancing in Multilink protocol was not working well. How do I record the log? Any suggession for the load balancing and SNMP problem? Thanks,

 

[lui3]

try sourcing your snmp from a loopback address.

Lui3
CCNP,CCDA,A+/Net+
Cisco Wireless Specialization

 

[lui3]

for syslog setup do the following

install and setup a syslog server on a win machine or linux box or unix. for windows i use solarwinds.net version. you can use kiwi cat tools as well. i think they are free.

anyways here is how it works on the router.

router#configure terminal
router(config)#logging x.x.x.x (with x being the ip address)

you can optionally set the logging level with the

router(config)#logging critical

or whatever level you want to use

i use logging debug

for debugging issues like you are seeing however i use acls to make sure i don't log traffic i don't need and i am careful to watch the cpu processes to make sure i don't blow up the router. debugging interrupts the cpu alot and can cause serious problems in high traffic networks. be careful.good luck.



Lui3
CCNP,CCDA,A+/Net+
Cisco Wireless Specialization