SF300 problems with IP Phone 3905

[Sergey Khrapov]

Hi,

cisco 2811 - DHCP server

If IP Phone 3905 installed in SF 300 he does not receive an ip address

May 23 09:35:08.799 MSK: DHCPD: DHCPREQUEST received from client 01cc.d539.d620.04.

May 23 09:35:08.799 MSK: DHCPD: client has moved to a new subnet.

May 23 09:35:08.799 MSK: DHCPD: Sending DHCPNAK to client 01cc.d539.d620.04.

May 23 09:35:08.803 MSK: DHCPD: broadcasting BOOTREPLY to client ccd5.39d6.2004.

c2811-vg-spb#

May 23 09:35:11.879 MSK: DHCPD: DHCPDISCOVER received from client 01cc.d539.d620.04 on interface FastE

thernet0/0.2.

May 23 09:35:11.879 MSK: DHCPD: Sending DHCPOFFER to client 01cc.d539.d620.04 (172.17.3.30).

May 23 09:35:11.883 MSK: DHCPD: broadcasting BOOTREPLY to client ccd5.39d6.2004.

May 23 09:35:11.959 MSK: DHCPD: DHCPREQUEST received from client 01cc.d539.d620.04.

May 23 09:35:11.959 MSK: DHCPD: Appending default domain from pool

May 23 09:35:11.963 MSK: DHCPD: Using hostname 'SEPCCD539D62004.spb.mbrd.ru.' for dynamic update (from

hostname option)

May 23 09:35:11.963 MSK: DHCPD: Sending DHCPACK to client 01cc.d539.d620.04 (172.17.3.30).

c2811-vg-spb#

May 23 09:35:11.963 MSK: DHCPD: broadcasting BOOTREPLY to client ccd5.39d6.2004.

If IP Phone 3905 installed in the Catalyst 2960 - all OK

Help to correctly configure SF 300.

[Sivaprasam Subramani]

Hello Sergey,

I will suggest you to verify the VLAN configuration. SF300 Switch has auto-voice vlan configured 100. Also verify allowed vlan in voice port. Try with DHCP relay option.

Please feel free to contact me if you have any queries.

Thanks and regards,

Siva

[Sergey Khrapov]

Hello Siva,

What do You mean SF300 has auto-voice vlan configured 100?

My configuration:

- Default-vlan = 1

- Voice Vlan ID = 2

- Auto Voice vlan  - enable

.Port configuration:

- switchport mode trunk

- switchport trunk native vlan 1

- switchport trunk allowed vlan add 2

The problem with the phone 3905 only, phone 6921 without problems gets an ip address.

[Tom Watts]

Hi Sergey, I'm not sure the 3905 phone supports CDP. But to do the right thing, if you manually configure a port as you have, you should not be using auto voice vlan or macro. They do have a tendancy to conflict with each other.

I also think this is a 10/100 phone? Try manually setting the port negotiation to 100 full and see if it makes any difference at all.

-Tom
Please mark answered for helpful posts

[Sergey Khrapov]

Hello Tom,

Disabled Smartport and auto voice vlan.

cSF300 #sh interfaces configuration

Port     Type         Duplex Speed Neg     Flow control Admin State Back Pressure Mdix Mode

fa1     100M-Copper Full   100   Enabled Off     Up     Disabled Auto

fa2     100M-Copper Full   100   Enabled Off     Up     Disabled Auto

fa3     100M-Copper Full   100   Enabled Off     Up     Disabled Auto

Problems not solved.

The DHCP server is working correctly,

phone 6921 obtains the IP address, the problem with the Phone 3905 - he does not obtains IP address

[elmo.omle]

I have the same problem as Sergey Khrapov, I can connect a cisco 6921, but I can not connect the 3901.

[Brandon Svec]

I would try to disable LLDP on the switch.  I had a similar issue with 3rd party IP phones on this type of switch.  It try to do a lot of things 'automagically' by default.

[Sergey Khrapov]

Solution - LLDP disable

[Karla Ledesma]

Did you leave the auto-voice vlan configuration?

I have the same problem with phones 3905, they don't get IP, actually when i saw the configuration on the phone voice vlan and default vlan is 4095 even when the switch SF300 has the auto-voice vlan configuration. Phones 69XX and 79XX doesn't have any issues, they got the correct voice vlan and the correct IP.

Tomorrow I will try doing the LLDP disable. Hope this works.

Thanks.