05-25-2011 11:00 AM - edited 03-04-2019 12:31 PM
I am setting up NEW T1 Connection. Getting Line Protocol Down.
Already tired replacing the cable, and replacing another router. Using Cisco 1721.
Also, tried loopback on WIC Card - Line protocol is down even when I put in loopback meaning problem is this router.
I have asked the telcom to confirm the following:
HDLC or PPC ? Clock Rate ? IP Address ?
In a mean while, if any one have any suggestions as to what else I can look for.
Also, I do not see nothing in Debug Interface Serial 0
-- No output - like serial 0 is not doing anything at all.
Please give me your suggestions. Output is attached.
Thanks
05-25-2011 11:55 AM
enable the t1 card by issuing the card type t1
you can use the show diag command to figure which slot the t1 card is installed in.
Please rate if this helps!
05-25-2011 12:20 PM
card type is showing up as invalid command on this router.
I am using 1721. Also tried it on 1841. On Both router(config)#card type ? is not showing any info - Saying unrecognized command. And Yes I did do this in config mode.
05-25-2011 02:39 PM
sorry didnt read the details of your original post. I believe there is an issue with layer 2. I see that you have checked most of them. This could be a ppp authentication issue or some kind of layer 2 ppp negotiation issue. if it is confirmed that the ISP is running PPP on the other end of the link, run the following debugs and then shut and no shut your interface. ensure to no shut your t1 controller too.
conf t
no logging console
logging buffered debug
end
debug ppp negotiation
debug ppp authentication
copy that output from your logs and upload that. if there is an authentication issue, you will see it here. any other PPP layer 2 issues you will see the failures in the LCP phase.
other thing you can try if for some reason you do not see the fix in the ppp debugs. check with the ISP on the below parameters
framing esf or sf?
linecode b8zs/ami?
maybe the t1 card is admin down. Issue a no shut.
maybe the ISP end is running some other layer 2 encapsulation other than PPP ---- frame-relay/ATM/HDLC etc?
Its probably one of the above issues.
Thanks
05-25-2011 10:30 PM
Do not use image attachements. Past e in show interface, sh controllers, show ver, show run.
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