[c-nsp] Cisco CMTS and ISC DHCP Strange Issue

[Rupesh Basnet]

HI Jean,

Thank you for your response.

We had really old ISC DHCP version and it doesn't support type 13 
messages which is used for leasequery. I will check removing source 
verify from bundle interface.

Regards,
--------
Rupesh Basnet

On 05/27/2014 05:53 AM, Jean-Francois.Dube at videotron.com wrote:
> Hi Rupesh,
>
> I suggest you first make sure DHCP works properly for the affected CPE.
>
> debug cable mac H.H.H
> debug cable dhcp
>
> These should allow you to see DHCP D.O.R.A. for a CPE with MAC H.H.H
>
> The CMTS needs to use leasequery (RFC 4388) if you experienced an outage of
> some sort to rebuild its internal database.
>
> If leasequery option 13 is not working properly with ISC servers then you
> may have this problem.
>
> You could try removing "cable source verify" as a test.
>
>
> Hope this helps.
>
> Cheers,
>
> JF
>
> Jean-François Dubé
> Technicien, Opérations Réseau IP
> Ingénierie Exploitation des Réseaux
> Vidéotron
> "cisco-nsp" <cisco-nsp-bounces at puck.nether.net> a écrit sur 2014-05-24
> 09:17:37 :
>
>> De : Rupesh Basnet <brupesh at subisu.net.np>
>> A : cisco-nsp at puck.nether.net,
>> Date : 2014-05-24 09:24
>> Objet : [c-nsp] Cisco CMTS and ISC DHCP Strange Issue
>> Envoyé par : "cisco-nsp" <cisco-nsp-bounces at puck.nether.net>
>>
>> Hi everyone,
>>
>> We have been using Cisco CMTS 7246 for about a decades. These days we
>> are facing some strange issue with CPE IP assigned by DHCP. We are using
>> ISC DHCP for both the modems and CPE. While I check modem searching for
>> the particular modem only then CPE taken is seen 0 but when I check cpe
>> with modem IP then I can see that customer CPE is taking IP address.
>> While checking on CMTS, the arp taken by CPE arp is also seen but no any
>> traffic are passing. If I bind the CPE mac and assign a IP then
>> everything gets to normal.
>>
>> CMTS is configure to relay on two DHCP services running on fail over
>> mode and soure verification is done for all the addresses.
>>
>> cmts2#show cable modem | in 814c
>> 00e0.6f70.814c 10.28.114.242   C3/1/U0   online       157   0.00 1942 *0
>> *  N
>>
>> cmts2#show cable modem 10.28.114.242 cpe
>> IP address        MAC address
>> *10.34.16.12      9061.0c15.2535 *
>>
>>
>> --
>> Regards,
>> --------
>> Rupesh Basnet
>>
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