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Webcast-Catalyst9k
New Member

Configure dual T-1's ???

                          Hello Guys,

                                           I have 2 T1 CSU-DSU WIC on one router and I need to configure both connections to the same service provider? What will the config look like on the T-1 interfaces? I want to load balance accross both T'-1's. Are the routes below correct to do this?

IP Address  for T-1   A

140.8.8.18 255.255.255.0

IP Address  for T-1   B

140.8.8.25  255.255.255.0

ip route 0.0.0.0 0.0.0.0 140.8.8.1

140.8.8.0 255.255.255.0 140.8.8.1

2 ACCEPTED SOLUTIONS

Accepted Solutions
Hall of Fame Super Silver

Re: Configure dual T-1's ???

Hello Ike,

this depends on the exact hardware that you have

on some devices you use something like

controller t1 0/0

channel-group 0 1-24

no shut

this creates interface

serial 0/0:0

you then configure it

int ser0/0:0

enc ppp

ip address x.x.x.x 255.255.255.252

no shut

in other cases the commands for the controller are embedded in the serial interface configuration instead of being under controller object

Hope to help

Giuseppe

Hall of Fame Super Silver

Re: Configure dual T-1's ???

Hello Ike,

this is a good question

with

channel-group 0 1-24

we create an object ser0/0:0 that includes all 24 DS0 channels and we use them as a single serial interface without worrying anymore about single B channels

We are using the T1 for data services only in this way.

the same happens also with the alternate command syntax

Hope to help

Giuseppe

6 REPLIES
Hall of Fame Super Silver

Re: Configure dual T-1's ???

Hello Ike,

you will need two default route with different ip next-hops belonging to the two different serial interfaces, also you should avoid to overlap the subnets

140.8.8.16/30

140.8.8.20/30

on the router interfaces

ip route 0.0.0.0 0.0.0.0 140.8.8.17

ip route 0.0.0.0 0.0.0.0 140.8.8.21

this is to perform load balancing, on the other side the SP needs to set two specific static routes like

ip route 140.8.8.128 255.255.255.128 140.8.8.18

ip route 140.8.8.128 255.255.255.128 140.8.8.22

that is given a /24 address space you need to perform appropriate subnetting for getting the IP addresses for the serial links

OR the provider can give one /24 for the LAN and two /30 subnets for the two point-to-point links (this is reasonable too) out of the /24 space

Hope to help

Giuseppe

New Member

Re: Configure dual T-1's ???

                        Thanks but, What will the configuration on the T-1 Controller Interfaces look like?

Hall of Fame Super Silver

Re: Configure dual T-1's ???

Hello Ike,

this depends on the exact hardware that you have

on some devices you use something like

controller t1 0/0

channel-group 0 1-24

no shut

this creates interface

serial 0/0:0

you then configure it

int ser0/0:0

enc ppp

ip address x.x.x.x 255.255.255.252

no shut

in other cases the commands for the controller are embedded in the serial interface configuration instead of being under controller object

Hope to help

Giuseppe

New Member

Re: Configure dual T-1's ???

                      Will this ip address be valid for all 24 channels on the T-1? I mean what about

seria0/0:1

seria0/0:2

seria0/0:3

and the other serial0/0:3 to 23

Or that only for a voice setup like DS0-GROUP or PRI-GROUP

Hall of Fame Super Silver

Re: Configure dual T-1's ???

Hello Ike,

this is a good question

with

channel-group 0 1-24

we create an object ser0/0:0 that includes all 24 DS0 channels and we use them as a single serial interface without worrying anymore about single B channels

We are using the T1 for data services only in this way.

the same happens also with the alternate command syntax

Hope to help

Giuseppe

New Member

Re: Configure dual T-1's ???

                                      Thanks Giuseppe,

                                                                I think I am good to go now.

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