2650 point to point T1 routing 1

[rlgaooa]

I am attaching my router configuration to connect three remote sites to one office using point to point T1 lines. Each remote site will be configured the same as router #2 so I have omitted them for the sake of brevity. I am waiting for the T1 lines so I have not had a chance to test these. Any comments would be greatly appreciated. I am using 2650 routers with 1-WIC-DSU/CSU-T1 cards at the remote sites and a 2650 router with 1-WIC-DSU/CSU-T1 and 1 VWIC-2MFT-T1 card for the main router
Main Router
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname 2650main
!
enable secret
enable password
!
ip subnet-zero
!
controller T1 0/1
framing esf
clock source internal
linecode b8zs
channel-group 0 timeslots 1-24 speed 64
!
controller T1 0/2
framing esf
clock source internal
linecode b8zs
channel-group 0 timeslots 1-24 speed 64
!
!
!
interface FastEthernet0/0
ip address 172.18.1.20 255.255.255.0
ip helper-address 172.18
speed auto
half-duplex
!
interface Serial0/0
description connected to branch office
ip unnumbered FastEthernet0/0
no fair-queue
service-module t1 clock source internal
service-module t1 remote-alarm-enable
!
interface Serial0/1:0
description connected to Nap Office
ip unnumbered FastEthernet0/0
!
interface Serial0/2:0
description Connected to San Office
ip unnumbered FastEthernet0/0
!
router rip
network 172.18.0.0
network 172.19.0.0
network 172.20.0.0
network 172.21.0.0
!
ip classless
no ip http server
ip pim bidir-enable
!
!
line con 0
line aux 0
line vty 0 4
password
login
!
no scheduler allocate
end

2650main#

Second Router

!
version 12.2
service timestamps debug uptime
service timestamps
service password-encryption
!
hostname 2650Branch
!
enable secret
!
ip subnet-zero
!
ip domain-name aooanwot.com
ip name-server 172.18.1.1
!
interface FastEthernet0/0
description connected to branch office
ip address 172.20.1.20 255.255.255.0
ip helper-address 172.18.1.1
duplex auto
speed auto
!
interface Serial0/0
description connected to main office
ip unnumbered FastEthernet0/0
fair-queue
service-module t1 remote-alarm-enable
!
router rip
version 2
network 172.20.0.0
no auto-summary
!
ip classless
no ip http server
ip pim bidir-enable
!
snmp-server community public RO
!
line con 0
exec-timeout 0 0
line aux 0
line vty 0 4
login
!
no scheduler allocate
end

2650Branch#

 

[nyy1023]

one word of caution is to check with the ISP, if you are connecting via an ISP or if these are true point to point t1's. Make sure to check the clock-rate?
You may need to point to line if the clocking is coming from the either the ISP or the Telco.

 

[IllegalOperation]

It should work, although I am concerned about using the ip unnumbered feature. Why not put a /30 on each serial interface?

Also, you are going to need to assign the correct DLCI for each of those links - but you wont get that information from your provider until it is time for them to install the circuits. Also, be carefull with the LMI and encapsulation type configuration. My provider uses IETF (which I believe is the default for Cisco), but they also use ANSI Annex D for the LMI (which is NOT the default with Cisco)....

 

[RobG2001]

I've had nothing but problems with those VWICs. I called TAC and one of the engineers said their meant more for voice than for a T1. On a point to point one end is set to clock internal and the other end is clock to the line.

 

[BuckWeet]

VWICS are awesome and give you more advanced capabilities than WIC modules do.

I agree put a /30 on each interface, if the ethernet goes down on either router, then the serial interface loses its IP, which will stop you from getting to the remote router.

 

[rlgaooa]

Thanks for all the tips, I am sorry about taking so long in getting back to you. I did remove the ip un-numbered and set addresses for the vwics. Routers are working fine. I also removed the ip helper-address as I was getting repeated udp broadcasts from a downstream domain controller that thought it was the master browser. This didn't seem to stop the forwarding of UDP packets. Any suggestions?

 

[IllegalOperation]

How about using an access list to block whatever traffic you dont want forwarded?