Mobile IP Configuration File

The mipagent command reads configuration information from the /etc/inet/mipagent.conf configuration file at startup. Mobile IP uses the /etc/inet/mipagent.conf configuration file to initialize the Mobile IP mobility agent. When configured and deployed, the mobility agent issues periodic router advertisements and responds to router discovery solicitation messages as well as Mobile IP registration messages.

See the mipagent.conf(4) man page for a description of file attributes. See the mipagent(1M) man page for a description of this file's usage.

Configuration File Format

The Mobile IP configuration file consists of sections. Each section has a unique name and is enclosed in square brackets. Each section contains one or more labels. You assign values to the labels by using the following format:

[Section_name]
     Label-name = value-assigned

Configuration File Sections and Labels describes the section names, labels, and possible values.

Sample Configuration Files

The default Solaris installation provides the following sample configuration files in the /etc/inet directory:

• mipagent.conf-sample – Contains a sample configuration for a Mobile IP agent that provides both foreign agent and home agent functionality

• mipagent.conf.fa-sample – Contains a sample configuration for a Mobile IP agent that provides only foreign agent functionality

• mipagent.conf.ha-sample – Contains a sample configuration for a Mobile IP agent that provides only home agent functionality

These sample configuration files contain mobile node address and security settings. Before you can implement Mobile IP, you must create a configuration file with the name mipagent.conf and place it in the /etc/inet directory. This file contains the configuration settings that satisfy your Mobile IP implementation requirements. You can also choose one of the sample configuration files, modify it with your addresses and security settings, and copy it to /etc/inet/mipagent.conf.

For more information, see How to Create the Mobile IP Configuration File.

mipagent.conf-sample File

The following listing shows the sections, labels, and values that are contained in the mipagent.conf-sample file. Configuration File Sections and Labels describes the syntax, sections, labels, and values.

[General]
   Version = 1.0    # version number for the configuration file. (required)
   
[Advertisements hme0]
   HomeAgent = yes
   ForeignAgent = yes
   PrefixFlags = yes
   AdvertiseOnBcast = yes
   RegLifetime = 200
   AdvLifetime = 200
   AdvFrequency = 5
   ReverseTunnel = no
   ReverseTunnelRequired = no
   
[GlobalSecurityParameters]
   MaxClockSkew = 300
   HA-FAauth = yes
   MN-FAauth = yes
   Challenge = no
   KeyDistribution = files

[Pool 1]
   BaseAddress = 10.68.30.7
   Size = 4

[SPI 257]
   ReplayMethod = none
   Key = 11111111111111111111111111111111

[SPI 258]
   ReplayMethod = none
   Key = 15111111111111111111111111111111

[Address 10.1.1.1]
   Type = node
   SPI = 258

[Address [email protected]]
   Type = node
   SPI = 257
   Pool = 1

[Address Node-Default]
   Type = node
   SPI = 258
   Pool = 1

[Address 10.68.30.36]
   Type = agent    
   SPI = 257[Address 10.68.30.36]    
   Type = agent    
   SPI = 257    
   IPsecRequest = apply {auth_algs md5 sa shared} 
   IPsecReply = permit {auth_algs md5}  
   IPsecTunnel =  apply {encr_algs 3des sa shared}

mipagent.conf.fa-sample File

The following listing shows the sections, labels, and values that are contained in the mipagent.conf.fa-sample file. Configuration File Sections and Labels describes the syntax, sections, labels, and values.

The mipagent.conf.fa-sample file shows a configuration that provides only foreign agent functionality. This sample file does not contain a Pool section because pools are used only by a home agent. Otherwise, this file is the same as the mipagent.conf-sample file.

[General]
   Version = 1.0    # version number for the configuration file. (required)
   
[Advertisements hme0]
   HomeAgent = no
   ForeignAgent = yes
   PrefixFlags = yes
   AdvertiseOnBcast = yes
   RegLifetime = 200
   AdvLifetime = 200
   AdvFrequency = 5
   ReverseTunnel = yes
   ReverseTunnelRequired = no
   
[GlobalSecurityParameters]
   MaxClockSkew = 300
   HA-FAauth = yes
   MN-FAauth = yes
   Challenge = no
   KeyDistribution = files

[SPI 257]
   ReplayMethod = none
   Key = 11111111111111111111111111111111

[SPI 258]
   ReplayMethod = none
   Key = 15111111111111111111111111111111

[Address 10.1.1.1]
   Type = node
   SPI = 258

[Address 10.68.30.36]
   Type = agent    
   SPI = 257[Address 10.68.30.36]    
   Type = agent    
   SPI = 257    
   IPsecRequest = apply {auth_algs md5 sa shared} 
   IPsecReply = permit {auth_algs md5}  
   IPsecTunnel = apply {encr_algs 3des sa shared}

mipagent.conf.ha-sample File

The following listing shows the sections, labels, and values that are contained in the mipagent.conf.ha-sample file. Configuration File Sections and Labels describes the syntax, sections, labels, and values.

The mipagent.conf.ha-sample file shows a configuration that provides only home agent functionality. Otherwise, this file is the same as the mipagent.conf-sample file.

[General]
   Version = 1.0    # version number for the configuration file. (required)
   
[Advertisements hme0]
   HomeAgent = yes
   ForeignAgent = no
   PrefixFlags = yes
   AdvertiseOnBcast = yes
   RegLifetime = 200
   AdvLifetime = 200
   AdvFrequency = 5
   ReverseTunnel = yes
   ReverseTunnelRequired = no

[GlobalSecurityParameters]
   MaxClockSkew = 300
   HA-FAauth = yes
   MN-FAauth = yes
   Challenge = no
   KeyDistribution = files

[Pool 1]
   BaseAddress = 10.68.30.7
   Size = 4

[SPI 257]
   ReplayMethod = none
   Key = 11111111111111111111111111111111

[SPI 258]
   ReplayMethod = none
   Key = 15111111111111111111111111111111

[Address 10.1.1.1]
   Type = node
   SPI = 258

[Address [email protected]]
   Type = node
   SPI = 257
   Pool = 1

[Address Node-Default]
   Type = node
   SPI = 258
   Pool = 1[Address 10.68.30.36]
    Type = agent    
    SPI = 257    
    IPsecRequest = apply {auth_algs md5 sa shared} 
    IPsecReply = permit {auth_algs md5}  
    IPsecTunnel = apply {encr_algs 3des sa shared}

Configuration File Sections and Labels

The Mobile IP configuration file contains the following sections:

• General (Required)

• Advertisements (Required)

• GlobalSecurityParameters (Optional)

• Pool (Optional)

• SPI (Optional)

• Address (Optional)

The General and GlobalSecurityParameters sections contain information relevant to the operation of the Mobile IP agent. These sections can appear only once in the configuration file.

General Section

The General section contains only one label: the version number of the configuration file. The General section has the following syntax:

[General]
     Version = 1.0

Advertisements Section

The Advertisements section contains the HomeAgent and ForeignAgent labels, as well as other labels. You must include a different Advertisements section for each interface on the local host that provides Mobile IP services. The Advertisements section has the following syntax:

[Advertisements interface]
     HomeAgent = <yes/no>
     ForeignAgent = <yes/no>
     .
     .

Typically, your system has a single interface, such as eri0 or hme0, and supports both home agent and foreign agent operations. If this situation exists for the example hme0, then the yes value is assigned to both the HomeAgent and ForeignAgent labels as follows:

[Advertisements hme0]
     HomeAgent = yes
     ForeignAgent = yes
     .
     .

For advertisement over dynamic interfaces, use '*' for the device ID part. For example, Interface-name ppp* actually implies all PPP interfaces that are configured after the mipagent daemon has been started. All the attributes in the advertisement section of a dynamic interface type remain the same.

The following table describes the labels and values that you can use in the Advertisements section.

Table 29-1 Advertisements Section Labels and Values

Label	Value	Description
HomeAgent	yes or no	Determines if the mipagent daemon provides home agent functionality.
ForeignAgent	yes or no	Determines if mipagent provides foreign agent functionality.
PrefixFlags	yes or no	Specifies if advertisements include the optional prefix-length extension.
AdvertiseOnBcast	yes or no	If yes, advertisements are sent on 255.255.255.255, rather than 224.0.0.1.
RegLifetime	n	The maximum lifetime value that is accepted in registration requests, in seconds.
AdvLifetime	n	The maximum length of time that the advertisement is considered valid in the absence of further advertisements, in seconds.
AdvFrequency	n	Time between two consecutive advertisements, in seconds.
ReverseTunnel	yes or noFA or HA or both	Determines if mipagent provides reverse-tunnel functionality. The value yes means that both the foreign agent and home agent support reverse tunneling. The value no means that the interface does not support reverse tunneling. The value FA means that the foreign agent supports reverse tunneling. The value HA means that the home agent supports reverse tunneling. The value both means that both the foreign agent and home agent support reverse tunneling.
ReverseTunnelRequired	yes or no	Determines if mipagent requires reverse tunnel functionality. Consequently, determines if a mobile node must request a reverse tunnel during registration. The value yes means that both the foreign agent and home agent require a reverse tunnel. The value no means that the interface does not require a reverse tunnel. The value FA means that the foreign agent requires a reverse tunnel. The value HA means that the home agent requires a reverse tunnel.
AdvInitCount	n	Determines the initial number of unsolicited advertisements. The default value is 1. This value is meaningful only if AdvLimitUnsolicited is yes.
AdvLimitUnsolicited	yes or no	Enables or disables a limited number of unsolicited advertisements over the mobility interface.

GlobalSecurityParameters Section

The GlobalSecurityParameters section contains the labels maxClockSkew, HA-FAauth, MN-FAauth, Challenge, and KeyDistribution. This section has the following syntax:

[GlobalSecurityParameters]
     MaxClockSkew = n
     HA-FAauth = <yes/no>
     MN-FAauth = <yes/no>
     Challenge = <yes/no>
     KeyDistribution = files

The Mobile IP protocol provides message replay protection by allowing timestamps to be present in the messages. If the clocks differ, the home agent returns an error to the mobile node with the current time and the mobile node can register again by using the current time. You use the MaxClockSkew label to configure the maximum number of seconds that differ between the home agent and the mobile node's clocks. The default value is 300 seconds.

The HA-FAauth and MN-FAauth labels enable or disable the requirement for home-foreign and mobile-foreign authentication, respectively. The default value is disabled. You use the challenge label so that the foreign agent issues challenges to the mobile node in its advertisements. The label is used for replay protection. The default value is disabled here, also.

The following table describes the labels and values that you can use in the GlobalSecurityParameters section.

Table 29-2 GlobalSecurityParameters Section Labels and Values

Label	Value	Description
MaxClockSkew	n	The number of seconds that mipagent accepts as a difference between its own local time and the time that is found in registration requests
HA-FAauth	yes or no	Specifies if HA-FA authentication extensions must be present in registration requests and replies
MN-FAauth	yes or no	Specifies if MN-FA authentication extensions must be present in registration requests and replies
Challenge	yes or no	Specifies if the foreign agent includes challenges in its mobility advertisements
KeyDistribution	files	Must be set to files

Pool Section

Mobile nodes can be assigned dynamic addresses by the home agent. Dynamic address assignment is done within the mipagent daemon independently of DHCP. You can create an address pool that can be used by mobile nodes by requesting a home address. Address pools are configured through the Pool section in the configuration file.

The Pool section contains the BaseAddress and Size labels. The Pool section has the following syntax:

[Pool pool-identifier]
     BaseAddress = IP-address
     Size = size

---

Note - If you use a Pool identifier, then it must also exist in the mobile node's Address section.

---

You use the Pool section to define address pools that can be assigned to the mobile nodes. You use the BaseAddress label to set the first IP address in the pool. You use the Size label to specify the number of addresses available in the pool.

For example, if IP addresses 192.168.1.1 through 192.168.1.100 are reserved in pool 10, the Pool section has the following entry:

[Pool 10]
     BaseAddress = 192.168.1.1
     Size = 100

---

Note - Address ranges should not encompass the broadcast address. For example, you should not assign BaseAddress = 192.168.1.200 and Size = 60, because this range encompasses the broadcast address 192.168.1.255.

---

The following table describes the labels and values that are used in the Pool section.

Table 29-3 Pool Section Labels and Values

Label	Value	Description
BaseAddress	n.n.n.n	First address in the address pool
Size	n	Number of addresses in the pool

SPI Section

Because the Mobile IP protocol requires message authentication, you must identify the security context by using a security parameter index (SPI). You define the security context in the SPI section. You must include a different SPI section for each security context that is defined. A numerical ID identifies the security context. The Mobile IP protocol reserves the first 256 SPIs. Therefore, you should use only SPI values greater than 256. The SPI section contains security-related information, such as shared secrets and replay protection.

The SPI section also contains the ReplayMethod and Key labels. The SPI section has the following syntax:

[SPI SPI-identifier]
     ReplayMethod = <none/timestamps>
     Key = key

Two communicating peers must share the same SPI identifier. You must configure them with the same key and replay method. You specify the key as a string of hexadecimal digits. The maximum length is 16 bytes. For example, if the key is 16 bytes long, and contains the hexadecimal values 0 through f, the key string might resemble the following:

Key = 0102030405060708090a0b0c0d0e0f10

Keys must have an even number of digits, corresponding to the two digits per byte representation.

The following table describes the labels and values that you can use in the SPI section.

Table 29-4 SPI Section Labels and Values

Label	Value	Description
ReplayMethod	none or timestamps	Specifies the type of replay authentication used for the SPI
Key	x	Authentication key in hexadecimal

Address Section

The Solaris implementation of Mobile IP enables you to configure mobile nodes using one of three methods. Each method is configured in the Address section. The first method follows the traditional Mobile IP protocol, and requires that each mobile node have a home address. The second method enables a mobile node to be identified through its Network Access Identifier (NAI). The last method enables you to configure a default mobile node, which can be used by any mobile node that has the proper SPI value and related keying material.

Mobile Node

The Address section for a mobile node contains the Type and SPI labels that define the address type and SPI identifier. The Address section has the following syntax:

[Address address]
     Type = node
     SPI = SPI-identifier

You must include an Address section in a home agent's configuration file for each mobile node that is supported.

If Mobile IP message authentication is required between the foreign agent and home agent, you must include an Address section for each peer with which an agent needs to communicate.

The SPI value that you configure must represent an SPI section that is present in the configuration file.

You can also configure private addresses for a mobile node.

The following table describes the labels and values that you can use in the Address section for a mobile node.

Table 29-5 Address Section Labels and Values (Mobile Node)

Label	Value	Description
Type	node	Specifies that the entry is for a mobile node
SPI	n	Specifies the SPI value for the associated entry

Mobility Agent

The Address section for a mobility agent contains the Type and SPI labels that define the address type and SPI identifier. This section also contains IPsec request, reply, and tunnel labels. The Address section for a mobility agent has the following syntax:

[Address address]
     Type = agent
     SPI = SPI-identifier
     IPsecRequest = action {properties} [: action {properties}]
     IPsecReply = action {properties} [: action {properties}]
     IPsecTunnel = action {properties} [: action {properties}]

You must include an Address section in a home agent's configuration file for each mobility agent that is supported.

If Mobile IP message authentication is required between the foreign agent and the home agent, you must include an Address section for each peer with which an agent needs to communicate.

The SPI value that you configure must represent an SPI section that is present in the configuration file.

The following table describes the labels and values that you can use in the Address section for a mobility agent.

Table 29-6 Address Section Labels and Values (Mobility Agent)

Label	Value	Description
Type	agent	Specifies that the entry is for a mobility agent
SPI	n	Specifies the SPI value for the associated entry
IPsecRequest	apply or permit (see following note)	IPsec properties to invoke for registration requests to and from this mobility agent peer
IPsecReply	apply or permit (see following note)	IPsec properties to invoke for registration replies to and from this mobility agent peer
IPsecTunnel	apply or permit (see following note)	IPsec properties to invoke for tunnel traffic to and from this mobility agent peer

---

Note - The apply values correspond to outbound datagrams. The permit values correspond to inbound datagrams. Therefore, IPsecRequest apply values and IPsecReply permit values are used by the foreign agent to send and receive registration datagrams. The IPsecRequest permit values and the IPsecReply apply values are used by the home agent to receive and send registration datagrams.

---

Mobile Node Identified by Its NAI

The Address section for a mobile node that is identified by its NAI contains the Type, SPI, and Pool labels. The NAI parameter enables you to identify mobile nodes through their NAI. The Address section, using the NAI parameter, has the following syntax:

[Address NAI]
     Type = Node
     SPI = SPI-identifier
     Pool = pool-identifier

To use pools, you identify mobile nodes through their NAI. The Address section permits you to configure an NAI, as opposed to a home address. An NAI uses the format user@domain. You use the Pool label to specify which address pool to use in order to allocate the home address to the mobile node.

The following table describes the labels and values that you can use in the Address section for a mobile node that is identified by its NAI.

Table 29-7 Address Section Labels and Values (Mobile Node Identified by Its NAI)

Label	Value	Description
Type	node	Specifies that the entry is for a mobile node
SPI	n	Specifies the SPI value for the associated entry
Pool	n	Allocates the pool from which an address is assigned to a mobile node

You must have corresponding SPI and Pool sections for the SPI and Pool labels that are defined in an Address section with a mobile node that is identified by its NAI, as shown in the following figure.

Figure 29-1 Corresponding SPI and Pool Sections for Address Section With Mobile Node Identified by Its NAI

Default Mobile Node

The Address section for a default mobile node contains the Type, SPI, and Pool labels. The Node-Default parameter enables you to permit all mobile nodes to get service if they have the correct SPI (defined in this section). The Address section, using the Node-Default parameter, has the following syntax:

[Address Node-Default]
     Type = Node
     SPI = SPI-identifier
     Pool = pool-identifier

The Node-Default parameter enables you to reduce the size of the configuration file. Otherwise, each mobile node requires its own section. However, the Node-Default parameter does pose a security risk. If a mobile node is no longer trusted for any reason, you need to update the security information on all trusted mobile nodes. This task can be very tedious. However, you can use the Node-Default parameter in networks that consider security risks unimportant.

The following table describes the labels and values that you can use in the Address section for a default mobile node.

Table 29-8 Address Section Labels and Values (Default Mobile Node)

Label	Value	Description
Type	node	Specifies that the entry is for a mobile node
SPI	n	Specifies the SPI value for the associated entry
Pool	n	Allocates the pool from which an address is assigned to a mobile node

You must have corresponding SPI and Pool sections for the SPI and Pool labels that are defined in the Address section with a default mobile node, as shown in the following figure.

Figure 29-2 Corresponding SPI and Pool Sections for Address Section With a Default Mobile Node