[cisco-voip] DHCP not really working [solved]
Kelemen Zoltan
keli at carocomp.ro
Mon Aug 20 14:29:32 EDT 2007
Hi,
Well it turns out, the DHCP server in Cisco did restart after the "no
service dhcp" line was removed from the config, but the 7911G phones act
rather irritatingly stupid as DHCP clients. They do not adhere to lease
times, but only try to refresh their IP addresses in the DHCP server
indefinitely.
Whatever a phone has received, it will not "let go" unless you
explicitly set so in the phone's network menu.
The debugs I was seeing were related probably to the fact, that phones
were trying to "refresh" the leased IP, but the router did not know
about such a lease (since the service was stopped, it's database was
empty). However none of the phones did a complete DHCP release/renew,
even though their adresses have expired much longer that 24hs before.
The newly added phone (as it was a remote location, I didn't do it, but
instructed somebody else) took an IP from the data VLAN before setting
it's administrative VLAN ID. After the latter was set, the phone got
blocked in a limbo, being in the voice VLAN, but looking for IPs in the
data VLAN. And this phone didn't "let go" neither of it's IP, nor it's
DHCP server, even after a long weekend.
So, my (rather miserable) opinion of the 7906/7911 series phones still
holds, unfortunately ...
regards,
Zoltan
Ted Nugent wrote:
> For testing why not add another network and DHCP scope
> to the unused interface of your router plug that into
> an access port (single vlan,not trunk) on the switch
> on the same vlan as one of the phones (also plugged
> into an access port), clear the config on the phone
> and see if it will pull an ip on a flat network.
>
>
> --- keli at carocomp.ro wrote:
>
>
>> I don't have a helper address there. I tried,
>> pointing it to it's own
>> IP, but obviously it just got worse :)
>>
>> Anyway, the phones have the Administrative VLAN set
>> manually, since
>> they are on a Dlink PoE switch, however, they were
>> working ok before
>> ... and seemingly the phones ARE trying to get an IP
>> on the proper
>> interface.
>>
>> Here are some more configs: 0/1.2 is the voice VLAN
>>
>> interface FastEthernet0/1
>> no ip address
>> duplex auto
>> speed auto
>> !
>> interface FastEthernet0/1.1
>> encapsulation dot1Q 1 native
>> ip address 192.168.181.230 255.255.255.0
>> h323-gateway voip interface
>> h323-gateway voip bind srcaddr 192.168.181.230
>> !
>> interface FastEthernet0/1.2
>> encapsulation dot1Q 42
>> ip address 192.168.42.1 255.255.255.0
>> !
>>
>> !
>> telephony-service
>> load 7910 P00403020214
>> load 7960-7940 P00307020200
>> load 7911 SCCP11.8-0-4SR3AS
>> max-ephones 42
>> max-dn 42
>> ip source-address 192.168.42.1 port 2000
>> auto assign 1 to 30
>> timeouts interdigit 5
>> system message KESZ Srl
>> url directories
>> http://1.2.3.4/fw/apps/Speedy/xml/directory.asp
>> url authentication
>> http://1.2.3.4/fw/authenticate.asp
>> time-zone 26
>> time-format 24
>> voicemail 899
>> max-conferences 8 gain -6
>> moh 14_kosheen_-_your_life.wav
>> multicast moh 239.23.4.10 port 2000
>> web admin system name *** password ***
>> dn-webedit
>> time-webedit
>> transfer-system full-consult
>> log password cisco
>> secondary-dialtone 9
>> xmltest
>> create cnf-files version-stamp 7960 Aug 17 2007
>> 17:32:58
>> !
>>
>> thanks,
>> Zoltan
>>
>> Quoting Ted Nugent <tednugent69 at yahoo.com>:
>>
>>
>>> You don't happen to have a helper address on your
>>> interface FastEthernet0/1.2 interface do you?
>>> Please provide a config for your interfaces and
>>> telephone service.
>>> Ted
>>>
>>> --- Kelemen Zoltan <keli at carocomp.ro> wrote:
>>>
>>>
>>>> Hi!
>>>>
>>>> It's a bit off-topic, however I'm all clueless,
>>>>
>> so
>>
>>>> any help would be
>>>> appreciated.
>>>>
>>>> I have a CCME (2811, with 12.4(13r)T), with 7911G
>>>> phones installed. Two
>>>> VLANs, one for data, one for voice.
>>>>
>>>> The router should be responsible for DHCP for the
>>>> phones, but it does
>>>> not seem to work - phones already in the network
>>>> have their IP adress,
>>>> keep their address through a reset, but new
>>>>
>> phones
>>
>>>> added to the network
>>>> can't get an IP.
>>>>
>>>> However, more people have access to the router
>>>>
>> and
>>
>>>> it is very possible
>>>> it might have been misconfigured.
>>>>
>>>> For starters, I noticed a
>>>>
>>>> no service dhcp
>>>>
>>>> in the running config, so I removed that. The
>>>>
>> dhcp
>>
>>>> debug messages began
>>>> to appear, but it seems like the router still
>>>>
>> can't
>>
>>>> find "itself":
>>>>
>>>> Aug 17 14:13:41.160: DHCPD: DHCPREQUEST received
>>>> from client
>>>> 0100.1bd4.60b5.e2.
>>>> Aug 17 14:13:41.160: DHCPD: Finding a relay for
>>>> client 0100.1bd4.60b5.e2
>>>> on interface FastEthernet0/1.2.
>>>> Aug 17 14:13:41.880: DHCPD: DHCPREQUEST received
>>>> from client
>>>> 0100.1bd4.609c.cf.
>>>> Aug 17 14:13:41.880: DHCPD: Finding a relay for
>>>> client 0100.1bd4.609c.cf
>>>> on interface FastEthernet0/1.2.
>>>>
>>>> Here are relevant parts of the configuration:
>>>>
>>>> no ip dhcp use vrf connected
>>>> ip dhcp excluded-address 192.168.42.1
>>>>
>> 192.168.42.2
>>
>>>> !
>>>> ip dhcp pool ITS
>>>> network 192.168.42.0 255.255.255.0
>>>> option 150 ip 192.168.42.1
>>>> default-router 192.168.42.1
>>>> !
>>>> !
>>>> no ip domain lookup
>>>>
>>>> ......................
>>>>
>>>> any ideas? useful show commands?
>>>> most sh ip dhcp ... commands show nothing, except
>>>> for
>>>>
>>>> Router#sh ip dhcp server statistics
>>>> Memory usage 23512
>>>> Address pools 1
>>>> Database agents 0
>>>> Automatic bindings 0
>>>> Manual bindings 0
>>>> Expired bindings 0
>>>> Malformed messages 0
>>>> Secure arp entries 0
>>>>
>>>> Message Received
>>>> BOOTREQUEST 0
>>>> DHCPDISCOVER 0
>>>> DHCPREQUEST 1912
>>>> DHCPDECLINE 0
>>>> DHCPRELEASE 0
>>>> DHCPINFORM 0
>>>>
>>>> Message Sent
>>>> BOOTREPLY 0
>>>> DHCPOFFER 0
>>>> DHCPACK 0
>>>> DHCPNAK 0
>>>>
>>>> Router#sh ip dhcp pool ITS
>>>>
>>>> Pool ITS :
>>>> Utilization mark (high/low) : 100 / 0
>>>> Subnet size (first/next) : 0 / 0
>>>> Total addresses : 254
>>>> Leased addresses : 0
>>>> Pending event : none
>>>> 1 subnet is currently in the pool :
>>>> Current index IP address range
>>>> Leased addresses
>>>> 192.168.42.1 192.168.42.1 -
>>>> 192.168.42.254 0
>>>>
>>>> Thanks,
>>>> Zoltan
>>>> _______________________________________________
>>>> cisco-voip mailing list
>>>> cisco-voip at puck.nether.net
>>>>
>>>>
>> https://puck.nether.net/mailman/listinfo/cisco-voip
>>
>>>
>>>
>>>
>>>
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