IP Pools

AAA and DHCP

Number of Address Pools

Default Pool Selection Cycle Method

• Number of Addresses in Pool

• Queue Type

• Pool Identifier

• Starting Pool IP Address

• Increment By

DHCP Only

• Pool n

• Alternate Pool Identifier

• Lease Time

Use the dropdown box to indicate the number of IP address pools. The number of IP Pool tabs depend on the number of IP address pools you select from the dropdown list.

Range: 1 - 30

Default: 1

Use the checkboxes to add another IP address pool. When a pool is added, its parameters are enabled. When its checkbox is cleared, the parameters are disabled.

Use the drop-down list to define the method used to select an address pool when more than one address pool is defined and a Pool Identifier or Alternate Pool Identifier is not provided in a request message.

Options:

• Exhaustive — All addresses in a pool are allocated before an address from the next address pool is allocated.

• Round-robin — An address is allocated from the first address pool, the next address is allocated from the second address pool, and so on. When an address is allocated from the last defined pool, the next address will be allocated from the first address pool.

Default: Exhaustive

Tcl Prameter: CycleMethod

The combination of Starting IP Address and Number of Addresses in Pool defines both the size of the pool and the addresses that can be allocated from it. When IPv6 addresses are used, you can specify the Increment By Portion of Address.

• Number of Addresses in Pool — The size of the address pool. Starting IP Address is incremented for each address in the pool.

• Range: Variable1

• Default: 1

• Tcl Parameter: NumAddrs_n (n = 1 to 30)

1 Maximum rates, number of sessions, and number of emulated nodes vary depending on the test configuration and the test system's licensed capacity.

Related Measurements

• • Allocate Fails Pool Empty

• Starting IP Address — The first IPv4 or IPv6 address for this address pool. The prefix length must be appended to the address when IPv6 addresses are used as it is used by Increment By Portion of Address to form the prefix returned in the Access Accept message.
  
  A mask may be included with an IPv4 address using slash notation. If an IPv4 mask is not included, a /32 mask (255.255.255.255) is returned.

Range:

• IPv4 — 0.0.0.0/0 (mask is optional)

• IPv6 — 0::0/0 (prefix length is mandatory)

Default: 1.1.1.1

Tcl Parameter: StartingIp_n (n = 1 to 30)

• Increment By: Indicates the incrementing Portion of Address, which does not apply when DHCP Address Type is IPv4. When you define an IPv6 address pool, you can use the radio buttons to determine which part of the address is incremented: the interface identifier or the subnet prefix. This selection is not applicable to IPv4 address pools.

Options: Interface-ID or Prefix

Default: Interface-ID

Use the radio buttons to select the method used to determine the order in which addresses are allocated from the pool.

Range:

• FIFO — All addresses are allocated from the pool in sequential order and then the oldest released address is allocated.

• LIFO — The most recently released address is allocated first. If no addresses have been released, addresses are allocated in sequential order.

Default: FIFO

When you define more than one address pool, the server node may compare Pool Identifier to information received in the request message in order to determine from which pool an address will be allocated.

Range: N/A

Default: None

Tcl Parameter: PoolId_n (n = 1 to 30)

AAA Testing

In the AAA Server Node test case, you can specify the IP Address Pool Selection Method. When you select Pool Name in Called-Station-Id for GPRS testing, the APN name in Pool Identifier will be compared to the APN name in the Called-Station-Id attribute received in an authentication request. If a match is found, an address from the pool is allocated and returned in the authentication response. Otherwise, an Access Reject message is returned to the NAS.

DHCP Testing

In the DHCP Server Node test case, various methods can be used to determine the address pool selected. When a discovery message contains the User Class option, the values are compared to the Pool Identifier for each defined pool to determine from which pool an address should be allocated. If a match is not found, no address is allocated.

• Address pool selection with IPv4

• Address pool selection with IPv6

Related Measurements

• Allocate Fails Pool Not Found

In the DHCP Server Node test case, the Alternate Pool Identifier may be used in the address pool selection process when more than one pool is defined. When the User Class option is not present in an IPv4 discover request that has been forwarded by a relay agent, the relay agent's IP address is compared to each pool's Alternate Pool Identifier.

• Address pool selection with IPv4

Use a network zone or scope format for the identifier. For example, if the starting pool address is 192.168.1.1 with a /16 mask, the identifier is 192.168.0.0.

Range: N/A

Default: None

Tcl Parameter: ipPoolId_1

Related Measurements

• Allocate Fails Pool Not Found

The maximum number of seconds that a DHCP client's binding can remain established before it expires. If the client requests a lease time after expiration, the request is ignored.

Range: N/A

Default: 36000

Tcl Parameter: leaseTime_1

Valid Lifetime

Applicable for IPv6 DHCP Address type and is the length of time an address remains in the valid state (i.e., the time until invalidation). When the valid lifetime expires, the address becomes invalid.

Renew Time T1 and Rebind Time T2 is available for DHCP IPv6 Address Type.  [see RFC 2131]

• Renew Time T1: When the value specified in the Renew Time T1 timer expires, a DHCPRequest is sent to the originating DHCP server asking for it’s lease to be extended. (When the DHCPRequest is received the server replies with a DHCPAck, extending the lease time).

• Rebind Time T2: Indicates the time at which the client enters the  REBINDING state and attempts to contact the server to extend the lease time. If no DHCPACK arrives before Rebind Time T2 expires, the client moves to REBINDING state and broadcasts a DHCPREQUEST message to extend its lease time.