Avaya P460 Manual Do Utilizador
Chapter 5
Avaya P460 Layer 3 Features
56
Avaya P460 Configuration Guide
BOOTP/DHCP (Dynamic Host Configuration Protocol) Relay
Configuration
Configuration
BOOTP/DHCP Overview
BOOTP
Short for Bootstrap Protocol, BootP is an Internet protocol that allows a diskless
workstation to discover the following:
•
workstation to discover the following:
•
Its own IP address
•
The IP address of a BOOTP server on the network
•
A file to be loaded into memory to boot the workstation.
BOOTP allows the workstation to boot without requiring a hard disk or diskette
drive. It is used when the user/station location changes frequently.
The protocol is defined by RFC 951.
drive. It is used when the user/station location changes frequently.
The protocol is defined by RFC 951.
DHCP
Short for Dynamic Host Configuration Protocol, DHCP assigns dynamic IP
addresses to devices on a network. With dynamic addressing, a device can have a
different IP address whenever the device connects to the network. In some systems,
the device's IP address can even change while it is still connected. DHCP also
supports a mix of static and dynamic IP addresses.
Dynamic addressing simplifies network administration because the software keeps
track of IP addresses rather than requiring an administrator to manage the task. This
means you can add a new computer to a network without the hassle of manually
assigning a unique IP address. Many ISPs use dynamic IP addressing for dial-up
users. However, dynamic addressing may not be desirable for a network server.
addresses to devices on a network. With dynamic addressing, a device can have a
different IP address whenever the device connects to the network. In some systems,
the device's IP address can even change while it is still connected. DHCP also
supports a mix of static and dynamic IP addresses.
Dynamic addressing simplifies network administration because the software keeps
track of IP addresses rather than requiring an administrator to manage the task. This
means you can add a new computer to a network without the hassle of manually
assigning a unique IP address. Many ISPs use dynamic IP addressing for dial-up
users. However, dynamic addressing may not be desirable for a network server.
DHCP/BOOTP Relay
The P460 supports the DHCP/BOOTP Relay Agent function. This is an application
that accepts DHCP/BOOTP requests that are broadcast on one VLAN. The
application sends them to a DHCP/BOOTP server. That server connects to another
VLAN or a server that might be located across one or more routers that might
otherwise not get the broadcast request. The relay agent handles the DHCP/BOOTP
replies as well. The relay agent transmits the replies to the client directly or as
broadcast, according to a flag in the reply message. Note that the same DHCP/
BOOTP relay agent serves both the BOOTP and DHCP protocols.
When there is more than one IP interface on a VLAN, the P460 chooses one of the IP
addresses on this VLAN when relaying the DHCP/BOOTP request. The DHCP/
BOOTP server then uses this address to decide from which subnetwork to allocate
the address.
that accepts DHCP/BOOTP requests that are broadcast on one VLAN. The
application sends them to a DHCP/BOOTP server. That server connects to another
VLAN or a server that might be located across one or more routers that might
otherwise not get the broadcast request. The relay agent handles the DHCP/BOOTP
replies as well. The relay agent transmits the replies to the client directly or as
broadcast, according to a flag in the reply message. Note that the same DHCP/
BOOTP relay agent serves both the BOOTP and DHCP protocols.
When there is more than one IP interface on a VLAN, the P460 chooses one of the IP
addresses on this VLAN when relaying the DHCP/BOOTP request. The DHCP/
BOOTP server then uses this address to decide from which subnetwork to allocate
the address.