Avaya 9 DHCP User Manual

Avaya Solution and Interoperability Test Lab

Red Hat Linux 9 DHCP Server Configuration for Avaya 4600 Series IP Telephones - Issue 1.0

Abstract

These Application Notes describe how to configure a Red Hat Linux 9 DHCP Server for Avaya 4600 Series IP Telephones. Dynamic Host Configuration Protocol (DHCP) provides a means by which configuration parameters can be automatically assigned to 4600 Series IP Telephones on a TCP/IP network, thus removing the need to individually assign and maintain IP addresses and other parameters for each IP telephone on the network. These Application Notes were written at the request of the Avaya Hosted Solutions team.

AM; Reviewed: WCH 3/18/2004

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Linux-DHCP.doc

1. Introduction

These Application Notes describe how to configure a Red Hat Linux 9 DHCP Server for Avaya 4600 Series IP Telephones. DHCP is a network protocol that provides a means by which configuration parameters can be automatically assigned to 4600 Series IP Telephones on a TCP/IP network, thus removing the need to individually assign and maintain IP addresses and other parameters for each IP Telephone on the network.

The sample configuration depicted in Figure 1 uses separate Virtual Local Area Networks (VLANs) for voice and data traffic. As a result, the DHCP configuration presented in these Application Notes supports scenarios where the switch ports may connect to a computer, an IP telephone, or an IP telephone with an attached computer. IEEE 802.1Q tagged VLAN ID 120 was used for the IP telephones, and untagged VLAN ID 130 was used for computers, whether standalone, or attached to an IP Telephone.

Figure 1: Red Hat Linux DHCP Server – Avaya IP Telephone Configuration

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Linux-DHCP.doc

The following DHCP server parameters were configured for the endpoints on the native data VLAN:

• Data endpoints IP address Range (178.16.13.100 – 178.16.13.250)

• Router IP address (178.16.13.1)

• Subnet broadcast IP address (178.16.13.255)

• Subnet Mask (255.255.255.0)

• L2Q=1 - IEEE 802.1Q trunking

• L2QVLAN=120 - Voice VLAN

The following DHCP server parameters were configured for the Avaya 4600 Series IP Telephones on the voice VLAN:

• Telephone IP address Range (178.16.12.100 – 178.16.12.250)

• Router IP address (178.16.12.1)

• Subnet broadcast IP address (178.16.12.255)

• Subnet Mask (255.255.255.0)

• IP address of C-LAN board – MCIPADD (178.16.12.21)

• Gatekeeper port - MCPORT (Default: 1719)

• TFTP server IP address – TFTPSRVR (178.16.12.100)

The following occurs when an IP telephone is installed (or reset). The IP telephone will initially send an untagged DHCP request. The Avaya P333R switch port is configured with both an untagged VLAN and tagged VLAN for the port. The untagged DHCP request will be associated with the untagged VLAN on the port. The Avaya P333R router interface on that VLAN has IP address 178.16.13.1. When the router interface relays the DHCP request to the configured DHCP server (178.16.13.66), it will use 178.16.13.1 as the source address. The DHCP server associates this request with the 178.16.13.0 scope and returns a reply with Option 176 string set, instructing the requestor to enable 802.1Q tagging with voice VLAN ID 120. The IP telephone receiving this reply will release the supplied IP address and issue a new DHCP request with VLAN ID 120. This request will be associated with the tagged VLAN on the port. The Avaya P333R interface of this VLAN has IP address 178.16.12.1 and will relay the DHCP request to the DHCP server with this address as the source. The DHCP server associates this address with scope 178.16.12.0 and replies with an IP address from that scope as well as several parameters in the Option 176 string.

Computers attached to the Avaya IP telephones issue untagged DHCP requests. These requests will be serviced the same as the initial request from the phone. However, the computer will ignore the Option 176 values specifying a new VLAN. Therefore, no new DHCP request is issued.

Note: The Avaya P333R switch and TFTP server configurations are out of the scope of this document. Please consult the appropriate user guides for more information on how to configure these devices.

AM; Reviewed: WCH 3/18/2004

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