On second look, I don’t see your routers interface (Gi0) having a native vlan to be able to move untagged traffic between itself and the switch. Usually ip phones get dhcp from data vlan.
Try changing voice subnet to something else and give x.x.15.0/24 to data vlan and see if that works. Kind Regards, Dennis -----Original Message----- From: Michael Ulitskiy [mailto:[email protected]] Sent: Tuesday, August 8, 2017 6:19 PM To: Dionisios Karopoulos <[email protected]> Cc: [email protected] Subject: RE: [c-nsp] Cisco IOS DHCP server problem Hello, I did. I tried to disable 'voice vlan' and put the phone in plain access vlan and disabled cdp. Still the same. Phone ignores DHCPOFFER. Any more ideas? Thanks, Michael -----Original Message----- From: Dionisios Karopoulos [mailto:[email protected]] Sent: Tuesday, August 8, 2017 2:38 AM To: 'Michael Ulitskiy' Cc: [email protected] Subject: RE: [c-nsp] Cisco IOS DHCP server problem Hello, Try disabling cdp/lldp towards the ip phone and see if it helps. Kind Regards, Dennis -----Original Message----- From: cisco-nsp [mailto:[email protected]] On Behalf Of Michael Ulitskiy Sent: Monday, August 7, 2017 10:06 PM To: [email protected] Subject: [c-nsp] Cisco IOS DHCP server problem Hello, I'm sorry to ask such a probably basic question, but I'm at loss. I have a very trivial setup: router (3825, IOS 15.0(1)M10) - switch (3750, IOS 12.2(50)SE5) - ip phone (7962, firmware SCCP42.9-3-1SR3-1S) For some reason the phone can't get ip address and I have no clue why. It looks like it discards router's DHCPOFFER. Here's what I'm getting in debugging after phone powering up: c199-41133# Aug 7 14:35:50: DHCPD: client's VPN is . Aug 7 14:35:50: DHCPD: DHCPDISCOVER received from client 010c.d996.9043.99 on interface GigabitEthernet0/0.20. Aug 7 14:35:50: DHCPD: Sending DHCPOFFER to client 010c.d996.9043.99 (10.10.15.38). Aug 7 14:35:50: DHCPD: broadcasting BOOTREPLY to client 0cd9.9690.4399. c199-41133# Aug 7 14:35:54: DHCPD: client's VPN is . Aug 7 14:35:54: DHCPD: DHCPDISCOVER received from client 010c.d996.9043.99 on interface GigabitEthernet0/0.20. Aug 7 14:35:54: DHCPD: Sending DHCPOFFER to client 010c.d996.9043.99 (10.10.15.38). Aug 7 14:35:54: DHCPD: broadcasting BOOTREPLY to client 0cd9.9690.4399. c199-41133# Aug 7 14:36:02: DHCPD: client's VPN is . Aug 7 14:36:02: DHCPD: DHCPDISCOVER received from client 010c.d996.9043.99 on interface GigabitEthernet0/0.20. Aug 7 14:36:02: DHCPD: Sending DHCPOFFER to client 010c.d996.9043.99 (10.10.15.38). Aug 7 14:36:02: DHCPD: broadcasting BOOTREPLY to client 0cd9.9690.4399. The config is very basic, subnet is directly attached, no dhcp relays: Router: ip dhcp pool DHCP-VOIP network 10.10.15.0 255.255.255.0 default-router 10.10.15.1 dns-server 10.10.15.1 ! interface GigabitEthernet0/0.20 description VOIP VLAN encapsulation dot1Q 20 ip address 10.10.15.1 255.255.255.0 no ip redirects no ip proxy-arp ip verify unicast source reachable-via rx 1 ip nat inside ip virtual-reassembly ! Switch: interface FastEthernet2/0/8 description Universal computer/phone port switchport access vlan 10 switchport mode access switchport voice vlan 20 spanning-tree portfast I did some googling, I found several people complaining about similar problem, but no solution. Does anyone have any idea what might be wrong here or how to further troubleshoot it? Thanks a lot, Michael _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
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