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dhcp request with dhcp off

Posted: 23 Mar 2011 05:50
by Konstantinos.E
hello guys

i have a wierd situation.4400 R8 with no ip telephony on it and dhcp off request ipadress from network.
the mac address that i am getting request is 00:80:9f:60:5d:dc the mac adress from my cpu is 00:80:9f:60:58:7f

you can c it in ifconfig command

eth0 Link encap:Ethernet HWaddr 00:80:9F:60:58:7F
inet addr:192.168.1.50 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:100682505 errors:0 dropped:0 overruns:0 frame:0
TX packets:27946074 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
Interrupt:12 Base address:0x9000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:72258 errors:0 dropped:0 overruns:0 frame:0
TX packets:72258 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0

tun0 Link encap:Ethernet HWaddr 00:FF:4F:75:63:6E
inet addr:172.30.253.1 Bcast:172.30.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:790 errors:0 dropped:0 overruns:0 frame:0
TX packets:3265 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100

when i unplug the lan cable from the cbrma box the requests stops.

How this is possible? :shock:

Re: dhcp request with dhcp off

Posted: 02 Apr 2011 14:17
by krzysioD
Some device on your net '00:80:9f:60:5d:dc' like ipphone or even a softphone 4068 sits on network and tries to have dhcp :)
Take port monitoring on your switch and plug out the other cable from the device, right? Or at least see mac table from your switch, then you have a port number :)

Re: dhcp request with dhcp off

Posted: 03 Apr 2011 10:12
by Konstantinos.E
the port from the switch witch am getting request is pluged on the port from the cbrma box...E0. the request comes from the pbx not an ipphone or smth else in the network.when i plug out the pbx from the network the request stops. :shock:

Re: dhcp request with dhcp off

Posted: 03 Apr 2011 12:48
by krzysioD
Must be kidding or i don't get it. you have both E1 and E0 connected to switch, proper jumpers on the CPUs?
Maybe another CPU (you have for example act 28 with cpu on #6 slot, and you plug brand new on #20) with embeded ethernet "on", tries to boot, it has no software, so it does dhcp discover and request.
Declare some dummy ip-shelf with this mac, and then see what's in the response of tftp from this mac.
for example, if i declared a intip3b remoteshelf, but it was a voice hub, in the 'plain text' on wireshark i've got 'bad position for this board' so.
Anyway, i don't get how the cpu with one mac, could have another mac and try to see dhcp client, don't you have any other equipment that is not properly configured?
1st time hear about this kind of behavior...

Re: dhcp request with dhcp off

Posted: 03 Apr 2011 13:19
by vad
If you know MAC address - check (must be written on each board) - CPU, INTIP, VPU5 (or another CPU from 4635 VM)