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Ciscco 1700 and 2600 series router is not communicating with Cisco 3800 series

Hello All,

I have a wierd issue. I have one 1700 series router with a T1 wick and another 3800 series router with several T1 wick. When I connect the 1700 to the 3800 using a t1 roll over cable the serial interfaces comes up then going back down repeatedly. I tried also connecting a 2600 to the 3800 series router with the same results. I keep getting CRC errors, input, and frame errors on the connected interfaces. We connected a hard loop to the 1700 and 3800 T1 wick cards and everything is working fine. What is wierd is when I connect the 1700 series router and 2600 series router together with a T1 roll over cable, they work without issues and the interface is stable. My question is why would connected each of these routers to the 3800 produce bad results. We have other wick cards on the 3800 that are connecting to other routers without problems. I even tried a seperate interface on the 3800 with the same problem. I have included my router configurations.  
Gendale-Router.TXT
Montebello-Router.TXT
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greenbeanx81
Asked:
greenbeanx81
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1 Solution
 
TakedaTCommented:
When you say "rollover" cable, what pinouts do you mean.  Typically, a "rolled"cable is used for console connections.  The pinouts for that are:
1-8
2-7
3-6
4-5
5-4
6-3
7-2
8-1

For a T1 "crossover" cable, you need different pinouts.
1-4
2-5
4-1
5-2

If your pinouts are correct, then you probably need to check your encapsulation settings on both ends of the cable to make sure they match.  By default, cisco routers use HDLC encapsulation.  If one end is using PPP (it looks like all your serial connections are using PPP on the Montabello router), then you would also need to use PPP on the other end (the Gendale router doesnt have the "encapsulation ppp" command configured).

I hope this helps.
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greenbeanx81Author Commented:
We used a T1 cross over cable with the same results. Encapsulation is set to HDLC. Still Having the same problem.
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TakedaTCommented:
Are these the two interfaces that you are crossconnecting?  I am guessing so because of the subnet matches.  If so, I believe that both sides or neither side of the link need to have the " service-module t1 data-coding inverted" line configured.  Not one having it and the other not.

Montebello:
interface Serial2/0/0
 description T1 to Verdugo
 ip address 172.252.1.1 255.255.255.252
 service-module t1 clock source internal
 service-module t1 timeslots 1-24
Gendale:
interface Serial0
 ip address 172.252.1.2 255.255.255.252
 no ip directed-broadcast
 no fair-queue
 service-module t1 clock source line
 service-module t1 data-coding inverted
 service-module t1 timeslots 1-24
!
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greenbeanx81Author Commented:
Thanks you. I added the "service-module t1 data-coding inverted" but still no luck bring the lline up.

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greenbeanx81Author Commented:
I never did find out why the routers will not talk to each other. They have no Cisco support so I guess I'll close this case.
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