06-12-2019 05:33 AM
HELLO Guys
I need your point of view about how can I run the this scenario
My IP Phone (Brand name: Polycom) should get IP from our Internet Service Provider DHCP server.
In order to do that the RJ45 cable from ISP switch (Cisco ASR 1000 x) connected to my 3750-G switch via interface Gigaethernet 24.
Our telephone connect to our HP Procure 2910al48G-Poe switch via port number 2.
My configuration on 3750 SW
SW-B6-C3750(config)vlan 2
SW-B6-C3750(config-vlan)name " VOICE-VLAN"
SW-B6-C3750 (config)interface vlan 2
SW-B6-C3750 (config-if)ip address 172.16.5.253 255.255.255.0
SW-B6-C3750 (config-if)do wr
SW-B6-C3750(config)interface gigabitEthernet 1/0/24
SW-B6-C3750(config-if)description BOUYGUES-VOICE-VLAN2
SW-B6-C3750(config-if)switchport access vlan 2
SW-B6-C3750(config-if)switchport trunk encapsulation dot1q
SW-B6-C3750(config-if)switchport voice vlan dot1p
SW-B6-C3750(config-if)switchport mode trunk
Show run
interface GigabitEthernet1/0/24
description BOUYGUES--VOICE--VLAN2
switchport access vlan 2
switchport trunk encapsulation dot1q
switch-port trunk allowed vlan 2
switch-port mode trunk
switch port voice vlan 2
no ip address
mls qos trust cos
no mdix auto
spanning-tree portfast trunk
interface Vlan2
description VOICE-VLAN
ip address 172.??.??.?? 255.255.255.0
Thank you in advance
Best
Ghasem
06-12-2019 05:44 AM
Hello Ghasem,
under Cisco 3750 SVI interface vlan 2 you need
int vlan 2
ip helper-address <DHCP-server-IP-address>
Access ports to which the IP phones connect should use the switchport voice vlan 2
Note:
The DHCP server needs to have configured the scope for the phones with the DHCP option used by Polycom to access the VOIP server.
Also the use of LLDP MED instead of CDP if supported by C3750 should be considered.
Hope to help
Giuseppe
06-12-2019 06:01 AM
Dear Giuseppe
First of all thanks for your comment, I did that command ( ip helper-address ) But still my phone did not get IP from ISP. phones should not get IP from our local DHCP server,
Thank you
Ghasem
06-12-2019 06:23 AM
Hello Ghasem,
have you configured the ip helper-address with the IP address of the ISP's DHCP server ?
If so you need to contact the ISP tech people that manages the server to verify that they receive the DHCP relayed requests from your C3750. And also they should verify the scope settings.
What models of Polycom phones are used ?
Hope to help
Giuseppe
06-12-2019 06:41 AM
Hello,
Yes, I've already configured.
Polycom vvx 411
Thank you
Best
Ghasem
06-12-2019 07:13 AM - edited 06-12-2019 07:19 AM
Hello Ghasem,
the following methods are supported by the phones for voice vlan discovery
VLAN-CDP, DHCP VLAN discovery, LLDP-MED for VLAN discovery
see
Verify what are the settings on the phones.
user guide link
Edit:
see also the following document about Vlan discovery on polycom phones
Hope to help
Giuseppe
06-13-2019 01:58 AM
Hello Giuseppe
Tnx for your replying, Still did not get IP from our ISP. :(
Best
Ghasem
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