Arris C3 CMTS problem (Modems are not receiving IP Address) | docsis.org

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Arris C3 CMTS problem (Modems are not receiving IP Address)

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zlate676
Arris C3 CMTS problem (Modems are not receiving IP Address)

Hello

We have an used Arrris C3 CMTS and we are performing some test before final instalation..
We have installed the CMTS, set the required parametars like ip helper address, upstream and downstream channels, frequencies, and we test 2 cable modems.

The modems have synchronized the Downstream and Upstream and they go in int(d) state…
After a while they go to offline mode but they never receive IP address...

Thank you in advance !!!

fb445421
DHCP failed

Hi!

You have a problem with the DHCP negotiation, hence the init(d). Either the DHCP server sends a lease that is not acceptable (time-server, next-server and router needs to be there) or the IP/DHCP packets from the server cannot find their way back to the CMTS. Try pinging or tracerouting to the C3 cable interface from the DHCP server. If you cannot, you have a routing problem. If you can, the DHCP server lacks an option in the DHCP OFFER.

Table 6-12 on page 6-119 in this document describes the different states:

http://docsis.beckitrue.com/documents/bsr/TPD-0034-01_rev_A.pdf

or:

http://docsis.beckitrue.com/documents/arris/C3_CMTS_Manual_R3.pdf

B.t.w. does the C3 run in routing or bridged mode? The above assumes routing mode. If you still have DHCP problems, what DHCP server do you use and under what OS?

/Fredrik

netcrash
Also you can take a look at

Also you can take a look at this:
http://blog.jasonantman.com/2010/04/dhcp-debugging-and-handy-tcpdump-fil...

to debug the cable modem dhcp packets

javierg
routing problem

Check your routing table. Ensure your CMTS it is in the same subnet of the DHCP server.

Regards.

zlate676
routing problem

Our CMTS can not ping the DHCP but the DHCP can ping the CMTS.. Can it be the reason for unsuccessful process of getting IP addresses for the modems? The CMTS is in routing mode ...

javierg
You have a Firewall in your

You have a Firewall in your Server?? What OS are you running??

Can you show you routing table??

javierg
You have a Firewall in your

You have a Firewall in your Server?? What OS are you running??

Can you show you routing table??

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