DHCP -> IP Phone

[snootalope]

hey guys... pretty noob question here

Ok, simple setup.

Router (1751) ----- Switch (3550) ----- Phone (7940)

I can't get that phone to pick up a DHCP address form the router!! I don't know if if it's the switch or what...

Got the DHCP pool setup on the router.. That pool is the same subnet and all as the IP of the Routers ethernet interface.

The routers Ehternet addy is 10.10.1.55
the pool is 10.10.1.0 255.255.255.0

From the switch(10.10.1.36), I can ping the router at 10.10.1.55

this is what my swichport looks like that the router is plugged into:

interface FastEthernet0/24
switchport trunk encapsulation dot1q
switchport mode trunk
switchport voice vlan 172
no ip address

From the router, using the sho ip dhcp pool stat, isn't showing any requests or anything..

what am i doing wrong here?

thanks guys

 

[lambent]

Is your router also running dot1q trunking? Do you mind posting the router config as well as the port config on your 3550 for the IP phones?

 

[snootalope]

ROUTER CONFIG:

boot-start-marker
boot system flash:123.10d.voxP.bin
boot-end-marker
!
logging buffered 4096 informational
no logging console
enable secret 5 $1$uxYJ$mf89CJuyX7E6hOiOl1RGn1
!
username scott privilege 15 password 7 13081200080405243F37
memory-size iomem 15
--More--  clock timezone CST -6
mmi polling-interval 60
no mmi auto-configure
no mmi pvc
mmi snmp-timeout 180
voice-card 1
!
no aaa new-model
ip subnet-zero
!
no ip dhcp conflict logging
ip dhcp excluded-address 10.10.1.55
ip dhcp relay information trust-all
!
ip dhcp pool 1
network 10.10.1.0 255.255.255.0
default-router 10.10.1.55
lease 55
!
ip cef
!
!
voice class codec 1
codec preference 1 g711ulaw
codec preference 2 g729r8
!
voice class h323 1
h225 timeout setup 3
!
class-map match-all VoIP-Control
match access-group 101
class-map match-all VoIP-RTP
match access-group 100
!
--More--  !
policy-map QoS-Policy-T1
class VoIP-RTP
priority 100
class VoIP-Control
bandwidth 16
class class-default
fair-queue
!
!
!
!
interface FastEthernet0/0
ip address 10.10.1.55 255.255.255.0
ip nat inside
speed auto
!
interface Serial0/0
ip address 192.168.4.2 255.255.255.252
service-policy output QoS-Policy-T1
ip tcp header-compression iphc-format
load-interval 30
h323-gateway voip bind srcaddr 192.168.4.2
--More--   ip rtp header-compression iphc-format
!
ip classless
ip http server
ip http authentication local
ip http timeout-policy idle 600 life 86400 requests 10000
!
!
access-list 100 permit ip any any precedence critical
access-list 100 permit ip any any dscp ef
access-list 101 permit ip any any precedence flash
access-list 101 permit ip any any dscp af31
!
snmp-server community acct RO
snmp-server enable traps tty
!
dial-peer cor custom

!
call-manager-fallback
ip source-address 172.17.17.5 port 2000
max-ephones 24
max-dn 48
access-code fxo 9
!


SWITCHPORT CONFIG:
!
interface FastEthernet0/12
switchport trunk encapsulation dot1q
switchport mode trunk
switchport voice vlan 172
!

 

[lambent]

Do you have data and voice running on the same VLAN, or only have voice and no data? If yes then you don't need dot1q trunking on your switch port and simply use this instead:

int f0/12
switchport access vlan 172
switchport mode access

 

[rubenmontilla]

Configure the following

ip dhcp pool 1
option 150 ip xxx.xxx.xxx.xxx (your call manager IP)

Good luck!