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Title | Size | Download |
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01-Text | 169.12 KB |
Feature and hardware compatibility
Configuring the mobile router feature
Configuring a roaming interface
Configuring a mobility security association
Displaying and maintaining NEMO
Configuring NEMO
Overview
Network mobility (NEMO) enables a node to retain the same IP address and maintain application connectivity when the node travels across networks. If the node is a mobile router, networks attached to the node can move with the node. All nodes on the moving networks can access the Internet without changing their IP addresses. NEMO implements location-independent routing of IP datagrams on the Internet.
Basic concepts
Home address
A home address is an IP address that is allocated to a mobile node. The mobile node uses this IP address for all communications.
Home network
A home network is the network where the home address of a mobile node resides. The network is attached to a home agent.
Mobile node
A mobile node (MN) is a mobile host or a router capable of reporting its current visiting network to the home agent.
Home agent
A home agent (HA) is a host or a router attached to the home network of a mobile node. The home agent saves the current location of the mobile node and forwards traffic to the mobile node.
Care-of address
A care-of address (CoA) identifies the location of a mobile node when the node is away from its home network. This CoA address is the local endpoint of the mobile IP tunnel to the home agent.
Collocated care-of address
A collocated care-of address (CCoA) is a care-of address that a mobile node obtains through manual configuration or DHCP.
Mobile router
A mobile router (MR) is a mobile node that provides connectivity for its mobile networks.
Mobile router operation
The mobile router operates as follows:
1. Sends a registration request to the home agent.
2. Receives a registration reply and performs the following operations:
? Creates a mobile IP tunnel automatically.
? Adds a default route destined for the home agent.
If the router does not receive any replies within the registration lifetime requested, it performs the following operations:
? Removes the registration information.
? Sends registration requests until a reply is received.
NEMO application scenarios
NEMO provides the following applications for connecting the mobile network to the home network:
· 3G or 4G wireless access.
· Wired access with the 3G or 4G wireless link as the backup link.
Connecting the mobile network to the home network through the 3G or 4G wireless link
As shown in Figure 1, a tunnel is established between the home agent and the 3G or 4G wireless modem interfaces of the mobile router. The mobile router and nodes on the mobile network can use the tunnel to access the home network.
When the mobile network roams, only the IP address of the 3G or 4G wireless modem interface of the mobile router changes.
The mobile router sends a registration request to the home agent and re-establishes a tunnel with the home agent. Hosts attaching to the mobile router are unaware of the IP address change. Services are not interrupted.
Figure 1 Connecting the mobile network and the home network through the wireless link
Connecting the mobile network to the home network through the wired link
As shown in Figure 2, the 3G or 4G wireless link is the backup link for the wired link between the mobile network and the home network.
When the mobile network roams, the wired link is disconnected. The mobile network is connected to the home network through the 3G or 4G wireless link. After the move is completed, the wired link is recovered, and the wireless link becomes the backup link.
Figure 2 Connecting the mobile network and the home network through the wired link
Registration message format
Registration request
A registration request contains the following fields:
· B—Broadcast datagrams.
· D—Decapsulation by mobile node.
· M—Minimal encapsulation.
· G—GRE encapsulation.
· r—Sent as zero. It is ignored on reception.
· T—Reverse tunneling requested.
· x—Sent as zero. It is ignored on reception.
· Home Address—Home address of the mobile node.
· Home Agent—IP address of the mobile node's home agent.
· Care-of Address—IP address for the mobile router end of the tunnel.
Figure 3 Registration request message format
Registration reply
A registration reply contains the following different fields than a registration request:
Figure 4 Registration reply message format
Authentication extension
An authentication extension contains the following fields:
· Type—Type of the extension. The value is 32.
· SPI—Security parameter index.
· Authenticator—Authentication data in cipher text.
Figure 5 Authentication extension format
Mobile network extension
A mobile network extension contains the following fields:
· Type—Type of the extension. The value is 148.
· Length—Length of the extension, excluding the Type filed. The value is 6.
· Sub-Type—Sub-type of the extension. The value is 0.
· Prefix Length—Prefix length of the mobile network.
· Prefix—Prefix of the mobile network.
Figure 6 Mobile network extension format
Normal Vendor/Organization Specific Extension (NVSE)
An NVSE extension contains the following fields:
· Type—Type of the extension. The value is 134.
· Length—Length of the extension, excluding the Type field.
· Reserved—Reserved for future use.
· Vendor/Org-ID—Vendor ID. The value 9 represents Cisco.
· Vendor-NVSE-Value—Value of the vendor NVSE extension.
Figure 7 NVSE format
NVSE prefix extension
An NVSE prefix extension contains the following fields:
· Length—Length of the extension. The value is 6.
· Prefix Length—Prefix length of the mobile network.
· Prefix—Prefix of the mobile network.
Figure 8 NVSE prefix extension format
Feature and hardware compatibility
Hardware |
Object group compatibility |
MSR810/810-W/810-W-DB/810-LM/810-W-LM/810-10-PoE/810-LM-HK/810-W-LM-HK |
Yes |
MSR810-LMS/810-LUS |
No |
MSR2600-6-X1 |
No |
MSR2600-10-X1 |
Yes |
MSR 2630 |
Yes |
MSR3600-28/3600-51 |
Yes |
MSR3600-28-SI/3600-51-SI |
No |
MSR3610-X1/3610-X1-DP/3610-X1-DC/3610-X1-DP-DC |
Yes |
MSR 3610/3620/3620-DP/3640/3660 |
Yes |
MSR5620/5660/5680 |
Yes |
Hardware |
NEMO compatibility |
MSR810-LM-GL |
Yes |
MSR810-W-LM-GL |
Yes |
MSR830-6EI-GL |
Yes |
MSR830-10EI-GL |
Yes |
MSR830-6HI-GL |
Yes |
MSR830-10HI-GL |
Yes |
MSR2600-6-X1-GL |
No |
MSR3600-28-SI-GL |
No |
Protocols and standards
· RFC 5177, Network Mobility (NEMO) Extensions for Mobile IPv4
· RFC 5944, IP Mobility Support for IPv4, Revised
NEMO configuration task list
Tasks at a glance |
(Required.) Configuring mobile IP |
(Required.) Configuring the mobile router feature |
(Required.) Configuring a roaming interface |
(Required.) Configuring a mobility security association |
Configuring NEMO
Enable mobile IP before you perform other tasks for NEMO configuration.
Configuring mobile IP
4. (Optional.) Set the tunnel interface number range for automatic tunnel creation. |
For information about the default tunnel interface number range, see NEMO Command Reference. |
Configuring the mobile router feature
Configuring a roaming interface
Configuring a mobility security association
For successful authentication, configure the same authentication mode and password on the mobile router and the home agent.
To configure a security association for authentication:
2. Configure a security association for authentication to the home agent. |
ip mobile secure home-agent ip-address spi hex-value key ascii { cipher | simple } string |
By default, no security association is specified on the router for authentication. For information about security associations, see Security Configuration Guide. |
Displaying and maintaining NEMO
Execute display commands in any view.
NEMO configuration example
Network requirements
As shown in Figure 9, the home agent is a Cisco device. The mobile router uses a USB 3G modem to register with the home agent and access the 3G network through Dial-on-Demand Routing (DDR).
Configure NEMO on the mobile router to meet the following requirements when the mobile network moves:
· The hosts on the mobile network use their home addresses for communication.
· Application connectivity is maintained on the hosts.
Configuration procedure
1. Configure the mobile router:
# Assign the IP address 20.1.1.1 to GigabitEthernet 1/0/1.
[MR] interface gigabitethernet 1/0/1
[MR-GigabitEthernet1/0/1] ip address 20.1.1.1 255.255.255.0
[MR-GigabitEthernet1/0/1] quit
[MR-MIP] quit
# Enable the mobile router feature.
# Assign a home address to the mobile router.
[MR-mobile-router] address 1.1.1.3
[MR-mobile-router] home-agent 1.1.1.2
# Specify GigabitEthernet 1/0/1 as the mobile router interface.
[MR-mobile-router] mobile-network gigabitethernet 1/0/1
[MR-mobile-router] quit
# Channelize Cellular 2/4/0 into a synchronous/asynchronous serial interface.
[MR] controller cellular 2/4/0
[MR-Cellular2/4/0] serial-set 0
[MR-Cellular2/4/0] quit
[MR-Serial2/4/0:0] ip mobile router-service roam
[MR-Serial2/4/0:0] quit
# Configure a security association that contains the home agent address 1.1.1.2, SPI 100, and the plaintext key abc. Make sure the same security association is configured on the home agent.
[MR] ip mobile secure home-agent 1.1.1.2 spi 100 key ascii simple abc
2. Configure the home agent as described in its user documentation. (Details not shown.)
Verifying the configuration
# Display registration information for the mobile router.
[MR] display ip mobile router registration
Registration accepted on 12/04/13 at 10:43:52, On Serial2/4/0:0
Care-of addr: 208.122.148.233, HA addr: 1.1.1.2, Home addr: 1.1.1.3
Lifetime requested: 65534, Granted: 36000
Remaining: 9 hours 58 minutes 36 seconds
Flags sbDmG-T-
Identification d64985e8.bd34f00e
Next registration: 9 hours 56 minutes 36 seconds
Extensions:
Mobile Network 20.1.1.0/24
Authentication SPI: 100
# Display registration information for the mobile router after it moves to another network.
[MR] display ip mobile router registration
Registration accepted on 12/04/13 at 11:35:45, On Serial2/4/0:0
Care-of addr: 212.48.124.187, HA addr: 1.1.1.2, Home addr: 1.1.1.3
Lifetime requested: 65534, Granted: 36000
Remaining: 9 hours 58 minutes 36 seconds
Flags sbDmG-T-
Identification d6499211.bc35e11d
Next registration: 9 hours 56 minutes 36 seconds
Extensions:
Mobile Network 20.1.1.0/24
Authentication SPI: 100
The output shows that the mobile router retains the home address and maintains the application connectivity when it moves.
Configuring NEMO,6
Displaying and maintaining NEMO,9
Feature and hardware compatibility,6
NEMO configuration example,9
NEMO configuration task list,6
Overview,1
Protocols and standards,6