Table of Contents

Chapter 1 Management VLAN Configuration. 1-1

1.1 Introduction to Management VLAN. 1-1

1.1.1 Management VLAN. 1-1

1.1.2 Static Route. 1-1

1.2 Management VLAN Configuration. 1-2

1.2.1 Prerequisites. 1-2

1.2.2 Configuring the Management VLAN. 1-2

1.2.3 Configuration Example. 1-3

1.3 Displaying Management VLAN Configuration. 1-4

Chapter 2 DHCP/BOOTP Client Configuration. 2-1

2.1 Introduction to DHCP Client 2-1

2.2 Introduction to BOOTP Client 2-3

2.3 DHCP/BOOTP Client Configuration. 2-4

2.3.1 Prerequisites. 2-4

2.3.2 Configuring a DHCP/BOOTP Client 2-4

2.3.3 Configuration Example. 2-5

2.4 Displaying the Information about a DHCP/BOOTP Client 2-6

 

Chapter 1  Management VLAN Configuration

1.1  Introduction to Management VLAN

1.1.1  Management VLAN

To manage an Ethernet switch remotely through Telnet or the built-in Web server, the switch need to be assigned an IP address. On H3C S3600 series Ethernet swithes, you can specify a management VLAN through related command.

The management VLAN interface of a switch can obtain an IP address in one of the following three ways:

l           Through the command used to configure IP address

l           Through BOOTP (In this case, the switch operates as a BOOTP client.)

l           Through dynamic host configuration protocol (DHCP) (In this case, the switch operates as a DHCP client)

The latest IP address obtained overwrites the previous one. That is, the latest IP address obtained causes the previously IP address to be released. For example, if you assign an IP address to a VLAN interface by using the corresponding commands and then apply for another IP address through BOOTP (using the ip address bootp-alloc command), the former IP address will be released, and the final IP address of the VLAN interface is the one obtained through BOOTP.

1.1.2  Static Route

A static route is configured manually by an administrator. You can make a network with relatively simple topology to operate properly by simply configuring static routes for it. Configuring and using static routes wisely helps to improve network performance and can guarantee bandwidth for important applications.

The disadvantages of static route lie in that: When a fault occurs or the network topology changes, static routes may become unreachable, which in turn results in network failures. In this case, manual configurations are needed to recover the network.

To access an S3600 series Ethernet switch through networks, you can configure static routes for it.

1.2  Management VLAN Configuration

1.2.1  Prerequisites

Before configuring the management VLAN, make sure the VLAN operating as the management VLAN exists. If VLAN 1 (the default VLAN) is the management VLAN, just go ahead.

1.2.2  Configuring the Management VLAN

Table 1-1 Configure the management VLAN

Operation	Command	Description
Enter system view	system-view	—
Configure a specified VLAN to be the management VLAN	management-vlan vlan-id	Required By default, VLAN 1 operates as the management VLAN.
Configure the default route	ip route-static 0.0.0.0 0.0.0.0 { null null-interface-number | next-hop } [ preference preference-value ] [ reject | blackhole ] [ detect-group detect-group-id ] [ description text ]	Required
Create the management VLAN interface and enter the corresponding VLAN interface view	interface vlan-interface vlan-id	Required
Assign an IP address to the management VLAN interface	ip address ip-address mask [ sub ]	Required By default, the management VLAN interface has no IP address.
Provide a description string for the management VLAN interface	description string	Optional By default, the description string of the management VLAN interface is “Vlan-interface vlan-id Interface”.
Shut down the management VLAN interface	shutdown	Optional By default, a management VLAN interface is down if all the Ethernet ports in the management VLAN are down; a management VLAN interface is up if one or more Ethernet ports in the management VLAN are up.
Bring up the management VLAN interface	undo shutdown

 

 

1.2.3  Configuration Example

I. Network requirements

To manage the switch SwitchA remotely through Telnet, These requirements are to be met: SwitchA has an IP address, and the route between SwitchA and the remote console is reachable.

You need to configure the switch as follows:

l           Assigning an IP address to the management VLAN interface

l           Configuring the default route

II. Configuration procedure

# Enter system view.

<H3C> system-view

# Create VLAN 10 and configure VLAN 10 to be the management VLAN.

[H3C] vlan 10

[H3C-vlan10] quit

[H3C] management-vlan 10

# Create the VLAN 10 interface and enter VLAN interface view.

[H3C] interface vlan-interface 10

# Configure the IP address of VLAN 10 interface to be 1.1.1.1.

[H3C-Vlan-interface10] ip address 1.1.1.1 255.255.255.0

[H3C-Vlan-interface10] quit

# Configure the default route.

[H3C] ip route-static 0.0.0.0 0.0.0.0 1.1.1.2

1.3  Displaying Management VLAN Configuration

Table 1-2 Display management VLAN configuration

Operation	Command	Description
Display the IP-related information about a management VLAN interface	display ip interface [ brief [ Vlan-interface [ vlan-id ] ] | [ Vlan-interface vlan-id ] ]	Optional You can execute the display commands in any view.
Display the information about a management VLAN interface	display interface vlan-interface [ vlan-id ]
Display summary information about the routing table	display ip routing-table
Display detailed information about the routing table	display ip routing-table verbose
Display the routes leading to a specified IP address	display ip routing-table ip-address [ mask ] [ longer-match ] [ verbose ]
Display the routes leading to a specified IP address range	display ip routing-table ip-address1 mask1 ip-address2 mask2 [ verbose ]
Display the routing information of the specified protocol	display ip routing-table protocol protocol [ inactive | verbose ]
Display the routing table in a tree structure	display ip routing-table radix
Display the statistics on the routing table	display ip routing-table statistics

 

Chapter 2  DHCP/BOOTP Client Configuration

2.1  Introduction to DHCP Client

As the network scale expands and the network complexity increases, the network configurations become more and more complex accordingly. It is usually the case that the computer locations change (such as the portable computers in wireless networks) or the number of the computers exceeds that of the available IP addresses. The dynamic host configuration protocol (DHCP) is developed to meet these requirements. DHCP adopts the client/server model, where DHCP clients request DHCP servers dynamically for configuration information, and the DHCP servers in turn return corresponding configuration information based on policies.

A typical DHCP implementation usually involves a DHCP server and multiple clients (such as PCs and portable computers), as shown in Figure 2-1.

Figure 2-1 A typical DHCP implementation

The interactions between a DHCP client and a DHCP server are shown in Figure 2-2.

Figure 2-2 The interaction between a DHCP client and a DHCP server

To obtain a valid IP address dynamically, a DHCP client exchanges different information with the DHCP server in different phases. Usually, the following three phases are involved.

1)         The DHCP client accesses the network for the first time

When a DHCP client accesses a network for the first time, it goes through the following four phases to establish connections with the DHCP server.

l           Discovery. The DHCP client tries to discover a DHCP server by broadcasting DHCP_Discover packets in the network. Only DHCP servers respond to this type of packets.

l           Offering IP addresses. Upon receiving DHCP_Discover packets, each DHCP server selects a free IP address from an address pool and sends a DHCP_Offer packet that carries the selected IP address and other configuration information to the DHCP client.

l           Selecting the IP address to be used. The DHCP client only accepts and processes the first-arrived DHCP_Offer packet (if multiple DHCP servers send DHCP_Offer packets to it), and broadcasts a DHCP_Request packet to each DHCP server. The packet contains the IP address carried in the DHCP_Offer packet the DHCP client receives.

l           Acknowledgement. Upon receiving the DHCP_Request packet, the DHCP server that owns the IP address carried in the DHCP_Request sends a DHCP_ACK packet to the DHCP client. The packet contains the IP address offered and other configuration information. The DHCP client binds TCP/IP protocol components to its MAC address after receiving the packet.

IP addresses offered by other DHCP servers (if any) through DHCP_Offer packets but not selected by the DHCP client are still available for other clients.

2)         The DHCP client accesses the network for the second and the followed time

In this case, the DHCP client establishes connections with the DHCP server through the following steps.

l           After accessing the network successfully for the first time, the DHCP client can access the network again by broadcasting a DHCP_Request packet that contains the IP address assigned to it last time instead of a DHCP_Discover packet.

l           Upon receiving the DHCP_Request packet and, when the IP address applied by the client is available, the DHCP server that owns the IP address responds with a DHCP_ACK packet to enable the DHCP client to use the IP address again.

l           If the IP address is not available (for example, it is assigned to another DHCP client), the DHCP server responds with a DHCP_NAK packet, which enables the DHCP client to request for a new IP address by sending a DHCP_Discover packet once again.

3)         The DHCP client extends the lease of an IP address

IP addresses assigned dynamically are only valid for a specified period of time and the DHCP servers reclaim their assigned IP addresses at the expiration of these periods. Therefore, a DHCP client need to extend the lease period if it is to use a dynamically assigned IP address for a period longer than allowed.

By default, a DHCP client updates its IP address lease automatically by sending DHCP_Request packets to the DHCP server when half of the lease period expires. The DHCP server, in turn, responds with a DHCP_ACK packet to notify the DHCP client of the new lease if the IP address is still available. An S3600 series switch operating as a DHCP support this lease auto-update process.

2.2  Introduction to BOOTP Client

A BOOTP client can request the server for an IP address through BOOTP. It goes through the following two phases to apply for an IP address.

l           Sending a BOOTP request packet to the server

l           Processing the BOOTP response packet received from the server

To obtain an IP address through BOOTP, a BOOTP client first sends a BOOTP request packet to the server. Upon receiving the request packet, the server returns a BOOTP response packet. The BOOTP client then retrieves the assigned IP address from the response packet.

The BOOTP packets are sent using user datagram protocol (UDP). To ensure reliable packet transmission, a timer is triggered when a BOOTP client sends a request packet to the server. If no response packet is received from the server after the timer times out, the client sends the request packet again. BOOTP request packets are sent every five seconds and three times at most. A BOOTP client stops sending BOOTP request packets if it fails to obtain an IP address after sending three successive BOOTP request packets.

2.3  DHCP/BOOTP Client Configuration

An S3600 series Ethernet switch can operate as a DHCP client or BOOTP client. In this case, the IP address of the management VLAN interface is obtained through DHCP or BOOTP.

2.3.1  Prerequisites

Before configuring the management VLAN, you need to create the VLAN that is to act as the management VLAN. As VLAN 1 is the default VLAN, there is no need to create it if you configure VLAN 1 to be the management VLAN.

2.3.2  Configuring a DHCP/BOOTP Client

Table 2-1 Configure a DHCP/BOOTP client

Operation	Command	Description
Enter system view	system-view	Required
Configure a specified VLAN to be the management VLAN	management-vlan vlan-id	Required By default, VLAN 1 operates as the management VLAN.
Create the management VLAN interface and enter VLAN interface view	interface vlan-interface vlan-id	Required
Configure the way in which the management VLAN interface obtains an IP address	ip address { bootp-alloc | dhcp-alloc }	Required By default, no IP address is assigned to the management VLAN interface.

 

 

2.3.3  Configuration Example

I. Network requirements

To manage the switch SwitchA remotely, which operates as a DHCP client, through Telnet, The following are required:

l           SwitchA obtains an IP address through DHCP

l           The route between SwitchA and the remote console is reachable.

To achieve this, you need to perform the following configuration for the switch:

l           Configuring the management VLAN interface to obtain an IP address through DHCP

l           Configuring a default route

II. Configuration procedures

# Enter system view.

<H3C> system-view

# Create VLAN 10 and configure VLAN 10 to be the management VLAN.

[H3C] vlan 10

[H3C-vlan10] quit

[H3C] management-vlan 10

# Create VLAN 10 interface and enter VLAN interface view.

[H3C] interface vlan-interface 10

# Configure the management VLAN interface to obtain an IP address through DHCP.

[H3C-Vlan-interface10] ip address dhcp-alloc

[H3C-Vlan-interface10] quit

# Configure the default route.

[H3C] ip route-static 0.0.0.0 0.0.0.0 1.1.1.2

2.4  Displaying the Information about a DHCP/BOOTP Client

Table 2-2 Display the information about a DHCP/BOOTP client

Operation	Command	Description
Display the information about IP address assignment on the DHCP client	display dhcp client [ verbose ]	Optional You can execute the display commands in any view.
Display the information about the BOOTP client	display bootp client [ interface vlan-interface vlan-id ]