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jmcrae72

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configuring two serial interfaces for Internet on a cisco 2621xm

i have a cisco 2621xm with two csu/dsu and i want to connect an Internet T-1 to each of them and have traffic flow through both of them simultaneously. i was given one IP for both circuits and a public LAN block.
this is the config i plan on using for both serial interfaces -
interface Serial0/0
 description Qwest Internet
 ip address 50.x.x.x 255.255.255.252
 ip verify unicast reverse-path
 no ip redirects
 no ip unreachables
 no fair-queue
 no cdp enable

this will only be a Internet router so i am thinking i will only need to configure a default route to make - correct?
please let me know if you need more information.
thanks in advance for your help!
jerry
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dlongan
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You will need a separate IP address for each csu/dsu - I believe.
I am not sure about load balancing with respect to a default route.  I would best guess you will need to pick one or the other to be the outbound route.  You could create two static default routes, but one should have a lower cost then the other.
dlongan is correct. This is an example:

interface Serial 0/0
  ip address 50.x.x.x 255.255.255.252

interface Serial 0/1
  ip address 50.x.x.y 255.255.255.252

ip route 0.0.0.0 0.0.0.0 50.x.x.w
ip route 0.0.0.0 0.0.0.0 50.x.x.z
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jmcrae72

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with some research of my own i found that you will need to configure a multilink interface then add the serial interfaces to the multilink group to setup two seperate T-1's to the Internet on the same router. i havent tested yet but i will post results when i do.



interface multilink1
 ip address 50.x.x.x 255.255.255.252
 no ip route-cache cef
 no ip route-cache
 no ip mroute-cache
 no cdp enable
 ppp multilink
 ppp multilink group 1

interface Serial0/0/0:0
 no ip address
 encapsulation ppp
 no ip route-cache cef
 no ip route-cache
 no fair-queue
 no cdp enable
 ppp multilink
 ppp multilink group 1
!
interface Serial0/0/1:0
 no ip address
 encapsulation ppp
 no ip route-cache cef
 no ip route-cache
 no fair-queue
 no cdp enable
 ppp multilink
 ppp multilink group 1

ip route 0.0.0.0 0.0.0.0 XXX.XXX.XXX.XXX
ASKER CERTIFIED SOLUTION
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GranMod

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