Avaya
4600 Series Administrator's Manual page 41

Examples of good DNS administration include the following:
- Option 6: "aaa.aaa.aaa.aaa"
- Option 15: "dnsexample.yourco.com"
- Option 66: "tftpserver.yourco.com,zzz.zzz.zzz.zzz"
- Option 176: "MCIPADD=xxxx.xxx.xxx.xxx"
Depending on the DHCP application you choose, you should be aware of the fact that
the application most likely will not immediately recycle expired DHCP leases. An
expired lease may remain reserved for the original client for a day or more (for
example, Windows NT
of this reservation period is to protect a client's lease in case the client and the DHCP
server are in two different time zones, the computers' clocks are not in synch, or the
client is not on the network when the lease expires.
The implication of this fact may be seen in the following example: Assume 2 IP
addresses (hence two possible DHCP leases) and three IP telephones, two of which
are using the two available IP addresses. When the lease expires for the first two
telephones, the third will not be able to get a lease (even if the other two telephones
have been removed from the network) until the reservation period expires.
The 4600 Series IP Telephone sets the indicated system values to the values of the indicated
fields of the DHCPACK message as indicated in
Table 4-3. DHCPACK Setting of System Values
System Value
IPADD
NETMASK
GIPADD
TFTPSRVR
The remainder of this section describes some common DHCP servers.
Windows NT 4.0 DHCP Server
®
This section contains details on how to verify and configure the DHCP server included in the
®
Windows NT 4.0 server operating system.
Use Verifying the Installation of the DHCP Server
installed. If it is not, install the DHCP server. If it is installed, go to the section
on page 4-10 and the following section.
®
DHCP reserves expired leases for about one day). The intent
Table 4-3
Set to
The yiaddr field.
Option #1 (if received).
The first four octets of option #3 (if received).
The first four octets of the siaddr field.
below to verify whether the DHCP server is
Server Administration
below.
4
Initial Configuration,
DHCP
4-9