Services. REFERENCE GUIDE DHCP DHCPv6 DNS Flow Monitoring LLDP NHRP sflow TWAMP. VYATTA A BROCADE COMPANY Vyatta System

Transcription

1 VYATTA A BROCADE COMPANY Vyatta System Services REFERENCE GUIDE DHCP DHCPv6 DNS Flow Monitoring LLDP NHRP sflow TWAMP Vyatta A Brocade Company 130 Holger Way San Jose, CA

2 COPYRIGHT Copyright Vyatta, a Brocade company. All rights reserved. Vyatta A Brocade Company reserves the right to make changes to software, hardware, and documentation without notice. PROPRIETARY NOTICES Vyatta A Brocade Company is a registered trademark of Brocade, Inc. Hyper-V is a registered trademark of Microsoft Corporation. VMware, VMware ESX, and VMware server are trademarks of VMware, Inc. XenServer, and XenCenter are trademarks of Citrix Systems, Inc. All other trademarks are the property of their respective owners. RELEASE DATE: March 2015 DOCUMENT REVISION. 3.5R1 v01 RELEASED WITH: Brocade Vyatta 3.5R1 PART NO

3 iii Contents Contents iii Quick List of Commands vi List of Examples xi Preface xiii Intended Audience xiv Product Applicability xiv Organization of this Guide xiv Document Conventions xv Vyatta Publications xvi Chapter 1 DHCP DHCP Overview DHCP Configuration Enabling the DHCP Server Configuring DHCP Address Pools Configuring DHCPv4 Address Pools for Networks Directly Connected to the Router Configuring Address Pools for Networks Indirectly Connected to the Router Creating a Static Mapping Setting Up DHCP Servers for Failover Setting Up DHCP Relay Setting Additional DHCP Configuration Parameters DHCP Commands Chapter 2 DHCPv DHCPv6 Overview DHCPv6 Configuration Enabling the DHCPv6 Server Configuring DHCPv6 Address Pools Configuring DHCPv6 Address Pools for Networks Directly Connected to the Router Configuring DHCPv6 Address Pools for Networks Indirectly Connected to the Router Creating a Static Mapping Setting up DHCPv6 Relay Setting up DHCPv6 Client DHCPv6 Commands

4 iv Chapter 3 DNS DNS Configuration DNS Overview System DNS Dynamic DNS DNS Forwarding DNS Configuration Examples Configuring Access to a Name Server Configuring Dynamic DNS Configuring DNS Forwarding Statically Configured Entries and DNS Forwarding DNS Commands Chapter 4 Flow Monitoring Flow Monitoring Overview Flow Monitoring Configuration Flow Monitoring Commands Chapter 5 LLDP LLDP Configuration LLDP Overview Configuring LLDP Displaying LLDP Information LLDP Commands Chapter 6 NHRP NHRP Overview NHRP and NBMA Networks NHSs and NHCs Supported Standards NHRP Configuration NHRP Commands Chapter 7 sflow sflow Overview Physical interfaces Packet-flow and port-counter sampling Packet-flow sampling Counter-flow sampling Communication with collectors Supported sflow Types

5 v Configuring sflow sflow Commands Chapter 8 TWAMP TWAMP Overview TWAMP Configuration Configuring the TWAMP Server Using twping to Measure IP Performance TWAMP Commands List of Acronyms

6 Quick List of Commands vi Use this list to help you quickly locate commands. clear flow-monitoring clear sflow interfaces dataplane <dp_port> sflow interfaces dataplane <interface> flow-monitoring selector <selector-name> interfaces tunnel <tunx> nhrp authentication <secret> interfaces tunnel <tunx> nhrp dynamic-map nbma-domain <nbma-domain-name> interfaces tunnel <tunx> nhrp dynamic-map protocol-address <protocol-addr>/<prefix> interfaces tunnel <tunx> nhrp holding-time <time> interfaces tunnel <tunx> nhrp map <protocol-addr>/<prefix> nbma-address <nbma-addr> interfaces tunnel <tunx> nhrp map <protocol-addr>/<prefix> register interfaces tunnel <tunx> nhrp map <protocol-addr>/<prefix> register-no-unique interfaces tunnel <tunx> nhrp multicast parameters interfaces tunnel <tunx> nhrp multicast protocol-address <protocol-addr> interfaces tunnel <tunx> nhrp redirect interfaces tunnel <tunx> nhrp shortcut interfaces tunnel <tunx> nhrp shortcut-destination interfaces tunnel <tunx> nhrp shortcut-target <protocol-addr>/<prefix> interfaces tunnel <tunx> nhrp shortcut-target holding-time <time> interfaces tunnel <tunx> nhrp release dhcp interface <interface> release dhcpv6 interface <interface> renew dhcp interface <interface> renew dhcpv6 interface <interface> reset dhcp server lease ip <address> reset dhcp server leases reset dhcpv6 server leases reset dns forwarding all reset dns forwarding cache reset ip nhrp flush tunnel reset ip nhrp purge tunnel restart dhcp relay-agent restart dhcp server

7 vii restart dhcpv6 relay-agent restart dhcpv6 server service dhcp-relay interface <interface> service dhcp-relay server <ipv4> service dhcp-relay service dhcp-relay relay-options service dhcp-server disabled <state> service dhcp-server dynamic-dns-update enable <state> service dhcp-server global-parameters <params> service dhcp-server listento interface <dp_interface> service dhcp-server shared-network-name <name> description <desc> service dhcp-server shared-network-name <name> disable service dhcp-server shared-network-name <name> shared-network-parameters <params> service dhcp-server shared-network-name <name> subnet <ipv4net> bootfile-name <bootfile> service dhcp-server shared-network-name <name> subnet <ipv4net> bootfile-sever <addr> service dhcp-server shared-network-name <name> subnet <ipv4net> client-prefix-length <prefix> service dhcp-server shared-network-name <name> subnet <ipv4net> default-router <ipv4> service dhcp-server shared-network-name <name> subnet <ipv4net> dns-server <ipv4> service dhcp-server shared-network-name <name> subnet <ipv4net> domain-name <domain-name> service dhcp-server shared-network-name <name> subnet <ipv4net> exclude <ipv4> service dhcp-server shared-network-name <name> subnet <ipv4net> failover local-address <ipv4> service dhcp-server shared-network-name <name> subnet <ipv4net> failover peer-address <ipv4> service dhcp-server shared-network-name <name> subnet <ipv4net> failover status <status> service dhcp-server shared-network-name <name> subnet <ipv4net> failover service dhcp-server shared-network-name <name> subnet <ipv4net> ip-forwarding enable <state> service dhcp-server shared-network-name <name> subnet <ipv4net> lease <seconds> service dhcp-server shared-network-name <name> subnet <ipv4net> ntp-server <ipv4> service dhcp-server shared-network-name <name> subnet <ipv4net> pop-server <ipv4> service dhcp-server shared-network-name <name> subnet <ipv4net> server-identifier <ipv4> service dhcp-server shared-network-name <name> subnet <ipv4net> smtp-server <ipv4> service dhcp-server shared-network-name <name> subnet <ipv4net> start <ipv4> stop <ipv4> service dhcp-server shared-network-name <name> subnet <ipv4net> static-mapping <mapname> disable service dhcp-server shared-network-name <name> subnet <ipv4net> static-mapping <mapname> ip-address <ipv4> 97 service dhcp-server shared-network-name <name> subnet <ipv4net> static-mapping <mapname> mac-address <mac>

8 viii service dhcp-server shared-network-name <name> subnet <ipv4net> static-mapping <mapname> static-mappingparameters <params> service dhcp-server shared-network-name <name> subnet <ipv4net> static-mapping <mapname> service dhcp-server shared-network-name <name> subnet <ipv4net> static-route destination-subnet <ipv4net> service dhcp-server shared-network-name <name> subnet <ipv4net> static-route router <ipv4> service dhcp-server shared-network-name <name> subnet <ipv4net> subnet-parameters <params> service dhcp-server shared-network-name <name> subnet <ipv4net> tftp-server-name <servername> service dhcp-server shared-network-name <name> subnet <ipv4net> time-offset <seconds> service dhcp-server shared-network-name <name> subnet <ipv4net> time-server <ipv4> service dhcp-server shared-network-name <name> subnet <ipv4net> wins-server <ipv4> service dhcp-server shared-network-name <name> subnet <ipv4net> wpad-url <url> service dhcp-server shared-network-name <name> subnet <ipv4net> service dhcp-server shared-network-name <name> authoritative <state> service dhcp-server shared-network-name <name> subnet <ipv4net> failover name <peer-name> service dhcp-server shared-network-name <name> service dhcp-server service dhcpv6-relay listen-interface <interface> service dhcpv6-relay listen-port <port> service dhcpv6-relay max-hop-count <count> service dhcpv6-relay upstream-interface <interface> service dhcpv6-relay use-interface-id-option service dhcpv6-relay service dhcpv6-server listento interface <dp_interface> service dhcpv6-server preference <preference> service dhcpv6-server shared-network-name <name> subnet <ipv6net> address-range prefix <pool-ipv6net>. 161 service dhcpv6-server shared-network-name <name> subnet <ipv6net> address-range start <start-ipv6> service dhcpv6-server shared-network-name <name> subnet <ipv6net> address-range service dhcpv6-server shared-network-name <name> subnet <ipv6net> description <desc> service dhcpv6-server shared-network-name <name> subnet <ipv6net> domain-search <domain> service dhcpv6-server shared-network-name <name> subnet <ipv6net> lease-time service dhcpv6-server shared-network-name <name> subnet <ipv6net> name-server <ipv6> service dhcpv6-server shared-network-name <name> subnet <ipv6net> nis-domain <nis-domain-name> service dhcpv6-server shared-network-name <name> subnet <ipv6net> nisplus-domain <nisplus-domain-name> service dhcpv6-server shared-network-name <name> subnet <ipv6net> nisplus-server <ipv6> service dhcpv6-server shared-network-name <name> subnet <ipv6net> nis-server <ipv6>

9 ix service dhcpv6-server shared-network-name <name> subnet <ipv6net> sip-server-address <ipv6> service dhcpv6-server shared-network-name <name> subnet <ipv6net> sip-server-name <sip-server-name> service dhcpv6-server shared-network-name <name> subnet <ipv6net> sntp-server-address <ipv6> service dhcpv6-server shared-network-name <name> subnet <ipv6net> static-mapping <mapping-name> service dhcpv6-server shared-network-name <name> subnet <ipv6net> service dhcpv6-server shared-network-name <name> service dhcpv6-server service dns dynamic interface <interface> service <service> host-name <hostname> service dns dynamic interface <interface> service <service> login <service-login> service dns dynamic interface <interface> service <service> password <service-password> service dns dynamic interface <interface> service <service> server <addr> service dns dynamic interface <interface> service <service> service dns dynamic interface <interface> service dns forwarding cache-size <size> service dns forwarding dhcp <interface> service dns forwarding listen-on <interface> service dns forwarding name-server <ipv4> service dns forwarding system service flow-monitoring exporter udp-collector address <ip-address> service flow-monitoring exporter udp-collector port <udp-port> service flow-monitoring selector <selector-name> randomly out-of <num-of-packets> service lldp interface <interface> location civic-based service lldp interface <interface> location coordinate-based service lldp interface <interface> location elin <phone-num> service lldp legacy-protocols <protocol> service lldp management-address <ipv4> service lldp service sflow agent-address <IPv4-or-IPv6> service sflow polling-interval <polling_rate> service sflow sampling-rate <sampling_rate> service sflow server-address <IPv4-or-IPv6> server-port <port> service twamp server client-list <ip-address> service twamp server dscp-value <value> service twamp server maximum-connections <count> service twamp server maximum-sessions-per-connection <count> service twamp server mode <authentication-mode>

10 x service twamp server port <port-number> service twamp server test-inactivity-timeout <seconds> service twamp server user <username> password <pwd> service twamp server service twamp server server-inactivity-timeout <seconds> show dhcp client leases show dhcp server leases show dhcp server statistics show dhcpv6 client leases show dhcpv6 relay-agent status show dhcpv6 server leases show dhcpv6 server status show dns dynamic status show dns forwarding nameservers show dns forwarding statistics show flow-monitoring show ip nhrp tunnel show lldp neighbors show service twamp server session [all client <ip-address> summary] show sflow twping <host-address> [auth-mode {authenticated encrypted mixed user <user>] [control-port <port>] [count <count>] [interval <seconds>] [padding <size>] [port-range <port1>-<port2>] [session-count <s-count>] [testdscp-value <dscp-value>] update dns dynamic interface <interface>

11 List of Examples xi Use this list to help you locate examples you would like to try or see. Example 1-1 Enabling the DHCP service Example 1-2 Configuring DHCP address pools Example 1-3 Configuring DHCP address pools Example 1-4 Creating a static mapping Example 1-5 Setting up DHCP failover on R Example 1-6 Setting up DHCP failover on R Example 1-7 Setting up DHCP relay Example 1-8 Setting up DHCP server with additional parameters Example 1-9 Displaying DHCP information for all interfaces configured as DHCP clients Example 1-10 Displaying all current DHCP lease information Example 1-11 Displaying all DHCP server statistics Example 2-1 Enabling the DHCPv6 service Example 2-2 Configuring a DHCPv6 address pool Example 2-3 Configuring a DHCPv6 address pool Example 2-4 Creating a static mapping Example 2-5 Setting up DHCPv6 relay Example 2-6 Setting up a DHCPv6 client on an Ethernet interface Example 3-1 Configuring static access to a DNS name server Example 3-2 Setting up dynamic DNS Example 3-3 Setting up DNS forwarding Example 3-4 Setting up static entries Example 3-5 Displaying update status for hosts configured for DDNS Example 3-6 Displaying the name servers being used for DNS forwarding Example 3-7 Displaying DNS forwarding statistics Example 4-1 Configuring the Flow Monitoring service Example 5-1 Enabling LLDP on a system Example 5-2 Configuring a civic-based location for LLDP Example 5-3 Configuring the physical coordinates of a system

12 xii Example 5-4 Showing LLDP neighbors Example 5-5 Showing detailed information on LLDP neighbors Example 5-6 Displaying a summary of link layer neighbors Example 5-7 Displaying details of link layer neighbors Example 6-1 Removing all non-permanent entries for the tun0 tunnel Example 6-2 Removing and reregistering all NHRP entries for the tun0 tunnel Example 6-3 Displaying NHRP information about the tun0 tunnel Example 7-1 Configuring sflow Example 7-2 Displaying sflow configuration information and usage statistics Example 7-3 Clearing the collected sflow statistics Example 8-1 Configuring the TWAMP service Example 8-2 Configuring the TWAMP service Example 8-3 Displaying the details of all current TWAMP sessions Example 8-4 Displaying the information for a specific TWAMP session Example 8-5 Displaying a summary of current TWAMP sessions

13 xiii Preface This guide describes the Layer 2 and Layer 3 software services supported on the Vyatta system. This preface provides information about using this guide. The following topics are presented: Intended Audience Product Applicability Organization of this Guide Document Conventions Vyatta Publications

14 Intended Audience xiv Intended Audience This guide is intended for experienced system and network administrators. Depending on the functionality to be used, readers should have specific knowledge in the following areas: Networking and data communications TCP/IP protocols General router configuration Routing protocols Network administration Network security IP services Product Applicability This guide describes software for the following products: Brocade Vyatta 5650 vrouter Brocade Vyatta 5655 vrouter Organization of this Guide This guide has the following aid to help you find the information for which you are looking: Quick List of Commands Use this list to help you quickly locate commands. List of Examples Use this list to help you locate examples you would like to see or try. This guide has the following chapters: Chapter Description Page Chapter 1: DHCP This chapter describes how to implement Dynamic Host Configuration Protocol (DHCP) on the Vyatta system. 1

15 Document Conventions xv Chapter 2: DHCPv6 Chapter 3: DNS Chapter 4: Flow Monitoring Chapter 5: LLDP Chapter 6: NHRP Chapter 7: sflow Chapter 8: TWAMP This chapter describes how to implement Dynamic Host Control Protocol version 6 (DHCPv6) on the Vyatta system. This chapter explains how to use Domain Name System (DNS) on the Vyatta System. This chapter describes how to configure the Flow Monitoring service on a Vyatta router. This chapter explains how to configure Link Layer Discovery Protocol (LLDP) for use on the Vyatta system. This chapter explains how to use the Next Hop Resolution Protocol (NHRP) addressing service on the Vyatta system. This chapter explains how to configure and manage sflow on the Vyatta router. This chapter describes how to configure a Two-Way Active Measurement Protocol (TWAMP) server on a Vyatta system for measuring round-trip IP performance between any two devices in a network that supports the standard List of Acronyms 350 Document Conventions This guide uses the following advisory conventions. WARNING A warning alerts you to situations that may pose a threat to personal safety. CAUTION A caution alerts you to situations that might cause harm to your system or damage to equipment or that may affect service. NOTE A note provides information you might need to avoid problems or configuration errors.

16 Vyatta Publications xvi This guide uses the following typographic conventions. Monospace bold Monospace bold italics <key> {key1 key2 [key1 key2] num1 numn arg1... argn arg[ arg...] arg[,arg...] An example, a command-line output, or a representation of a configuration node. Your input, that is, something you type at a command line. A command, keyword, or file name when mentioned in the text. An object in the user interface, such as a tab, button, screen, or pane. An argument or variable for which you supply a value. A key on your keyboard, such as <Enter>. Combinations of keys are joined by plus signs (+), as in <Ctrl>+c. Enumerated requirements for completing a syntax. An example is {start stop. Enumerated options for completing a syntax. An example is [enable disable]. An inclusive range of numbers. An example is , which means 1 through 65535, inclusive. A range of enumerated values. An example is eth0... eth3, which means eth0, eth1, eth2, or eth3. A value that represents a list of elements separated by spaces or commas, respectively. Vyatta Publications The Vyatta technical library provides full product documentation. To see what documentation is available for your release, refer to Guide to Vyatta Documentation. This guide is posted with every release of Vyatta software and provides a great starting point for locating the information you need. Additional information is available at the following sites: vrouter/index.page

17 1 Chapter 1: DHCP This chapter describes how to implement Dynamic Host Configuration Protocol (DHCP) on the Vyatta system. This chapter presents the following topics: DHCP Overview DHCP Configuration DHCP Commands

18 Chapter 1: DHCP DHCP Overview 2 DHCP Overview DHCP allows dynamic assignment of reusable IP addresses and other configuration information to DHCP clients. This assignment reduces costs, configuration effort, and management burden associated with Internet access. On the other hand, it also increases network and service overhead. In DHCP, the server assigns an IP address and other configuration parameters to a client for a limited period of time. This period of time is called the lease. The lease is valid for the period you configure on the Vyatta system or until the client explicitly relinquishes the address. To use the DHCP service, you define a pool of IP addresses for each subnet assigned by the DHCP server. Each DHCP address pool is mapped to a subnet associated with the system. For each address pool, you can specify the length of time an address is valid (its lease duration). The default lease duration is 24 hours. You can also specify a number of different servers (for example DNS, WINS, SMTP, and others) that are available to clients on the subnet. To create an IP address pool for clients on a subnet to which the router is not directly connected (that is, without having an interface into that network), as shown in Figure 1-2, you can use the listento option of the dhcp-server command, as shown in Example 1-3. You can statically map an IP address to the MAC address of a device. The DHCP service listens on UDP port 67 for lease requests from DHCP clients. The request packet allows the system to determine the interface on which the client is located. It then assigns an IP address from the appropriate pool and binds it to the client. In addition to providing a DHCP server, individual interfaces on the Vyatta system can be configured as DHCP clients. For details, see the Vyatta documentation for the interface you are interested in configuring as a DHCP client. The Vyatta system also supports DHCP relay. A DHCP relay agent receives DHCP packets from DHCP clients and forwards them to a DHCP server. This allows you to place DHCP clients and DHCP servers on different networks; that is, across router interfaces. The relay agent is configured with addresses of DHCP servers to which they should relay client DHCP message. The relay agent intercepts the broadcast, sets the gateway address (the giaddr field of the DHCP packet) and, if configured, inserts the Relay Agent Information option (option 82) in the packet and forwards it to the DHCP server. The DHCP server echoes the option back verbatim to the relay agent in server-to-client replies, and the relay agent strips the option before forwarding the reply to the client.

19 Chapter 1: DHCP DHCP Configuration 3 DHCP Configuration This section includes the following examples: Enabling the DHCP Server Configuring DHCP Address Pools Creating a Static Mapping Setting Up DHCP Servers for Failover Setting Up DHCP Relay Setting Additional DHCP Configuration Parameters Enabling the DHCP Server To use the DHCP server on the Vyatta System, you must enable the DHCP service. To enable the DHCP service, perform the following steps in configuration mode. Example 1-1 Enabling the DHCP service Step Enable DHCP. Command vyatta@r1# set service dhcp-server In addition, at least one DHCP shared network (address pool) must be configured. Configuring DHCP Address Pools Configure DHCP address pools for the system to act as a DHCP server for the network. Configuring DHCPv4 Address Pools for Networks Directly Connected to the Router Example 1-2 shows how to create three address pools: dp0p1p1_pool. This address pool serves the /24 subnet, which is connected to the dp0p1p1 interface. The lease time remains at the default, 24 hours (86,400 seconds). This address pool uses the DNS name server at dp0p1p2_30_pool. This address pool serves the /24 subnet, which is connected directly to the dp0p1p2 interface. The lease time remains at the default, 24 hours (86,400 seconds). This address pool uses the DNS name server at , which is directly connected to dp0p1p2.40 (that is, dp0p1p2 virtual interface [vif] 40).

20 Chapter 1: DHCP DHCP Configuration 4 dp0p1p2_40_pool. This address pool serves the /24 subnet, which is connected to the dp0p1p2.40 interface. The lease time remains at the default, 24 hours (86,400 seconds). This address pool uses the DNS name server at , which is connected to dp0p1p2.40. In all these pools, the range of addresses is configured for.100 through.199. Figure 1-1 shows the sample address pool configuration. Figure 1-1 DHCP address pool configuration /24 Address Pool: dp0p1p1_pool Subnet: /24 Start Address: Stop Address: Lease (Seconds): 86,400 DNS Server: dp0p1p1.65 R1 dp0p1p2.65 dp0p1p2 vif / /24 Address Pool: dp0p1p2_30_pool Subnet: /24 Start Address: Stop Address: Lease (Seconds): 86,400 DNS Server: Address Pool: dp0p1p2_40_pool Subnet: /24 Start Address: Stop Address: Lease (Seconds): 86,400 DNS Server: To configure DHCP address pools, perform the following steps in configuration mode. Example 1-2 Configuring DHCP address pools Step Create the configuration node for dp0p1p1_pool on the /24 subnet. Specify the start and stop IP addresses for the pool. Specify the default router for dp0p1p1_pool. Command vyatta@r1# set service dhcp-server shared-network-name dp0p1p1_pool subnet /24 start stop vyatta@r1# set service dhcp-server shared-network-name dp0p1p1_pool subnet /24 default-router

21 Chapter 1: DHCP DHCP Configuration 5 Example 1-2 Configuring DHCP address pools (Continued) Specify a DNS server for dp0p1p1_pool. Create the configuration node for dp0p1p2_30_pool on the /24 subnet. Specify the start and stop IP addresses for the pool. Specify the default router for dp0p1p2_30_pool. Specify a DNS server for dp0p1p2_30_pool. Create the configuration node for dp0p1p2_40_pool on the /24 subnet. Specify the start and stop IP addresses for the pool. Specify the default router for dp0p1p2_40_pool. Specify a DNS server for dp0p1p2_40_pool. Commit the changes. vyatta@r1# set service dhcp-server shared-network-name dp0p1p1_pool subnet /24 dns-server vyatta@r1# set service dhcp-server shared-network-name dp0p1p2_30_pool subnet /24 start stop vyatta@r1# set service dhcp-server shared-network-name dp0p1p2_30_pool subnet /24 default-router vyatta@r1# set service dhcp-server shared-network-name dp0p1p2_30_pool subnet /24 dns-server vyatta@r1# set service dhcp-server shared-network-name dp0p1p2_40_pool subnet /24 start stop vyatta@r1# set service dhcp-server shared-network-name dp0p1p2_40_pool subnet /24 default-router vyatta@r1# set service dhcp-server shared-network-name dp0p1p2_40_pool subnet /24 dns-server vyatta@r1# commit

22 Chapter 1: DHCP DHCP Configuration 6 Example 1-2 Configuring DHCP address pools (Continued) Show the configuration. Show the interface configuration. vyatta@r1# show service dhcp-server shared-network-name dp0p1p1_pool { subnet /24 { default-router dns-server start { stop shared-network-name dp0p1p2_30_pool { subnet /24 { default-router dns-server start { stop shared-network-name dp0p1p2_40_pool { subnet /24 { default-router dns-server start { stop vyatta@r1# show interfaces dataplane dp0p1p1 { address /24 hw-id 00:0c:29:42:05:2b dataplane dp0p1p2 { address /24 hw-id 00:0c:29:42:05:35 vif 40 { address /24

23 Chapter 1: DHCP DHCP Configuration 7 Configuring Address Pools for Networks Indirectly Connected to the Router Example 1-3 shows how to create an address pool (dp0p1p1_pool2) for clients that are indirectly connected to the Vyatta R1 router, as shown in Figure 1-2: The dp0p1p1_pool2 address pool serves the /24 subnet, which is on a different subnet than the subnet to which the dp0p1p1 data-plane interface is connected. The lease time remains at the default, 24 hours (86,400 seconds). This address pool uses the DNS name server at Figure 1-2 shows the sample address pool configuration. Figure 1-2 DHCP address pool configuration for clients indirectly connected to the DHCP server host To configure the dp0p1p1_pool2 DHCP address pool, perform the following steps in configuration mode. Example 1-3 Configuring DHCP address pools Step Configure the router interface to listen to DHCP messages. Command vyatta@r1# set service dhcp-server listento interface dp0p1p1

24 Chapter 1: DHCP DHCP Configuration 8 Example 1-3 Configuring DHCP address pools (Continued) Create a shared network and associate it with the /24 subnet. Show the configuration. Show the interface configuration. Commit the changes. vyatta@r1# set service dhcp-server shared-network-name dp0p1p1_pool2 subnet /24 vyatta@r1# show service dhcp-server dhcp-server { listento { interface dp0p1p1 shared-network-name dp0p1p1_pool2 { subnet /24 { dns-server lease start { stop vyatta@r1# show interfaces interfaces { dataplane dp0p1p1 { address /24 loopback lo vyatta@r1# commit Creating a Static Mapping Situations exist in which it makes sense to map a specific IP address to a specific host rather than dynamically assign an IP address from a pool of addresses. This mapping is known as a static mapping. A static mapping is defined by using the static-mapping option of the service dhcp-server configuration node. The following example shows how to add a static mapping to dp0p1p1_pool, which is created in Example 1-2. Example 1-4 shows how to map the IP address to the device with a MAC address of 00:15:c5:b3:2e:65.

25 Chapter 1: DHCP DHCP Configuration 9 Example 1-4 Creating a static mapping Step Create a static mapping called lab and specify the static IP address within the dp0p1p1_pool pool. Specify the associated MAC address within the lab static mapping in the dp0p1p1_pool pool. Commit the changes. Show the configuration. Command vyatta@r1# set service dhcp-server shared-network-name dp0p1p1_pool subnet /24 static-mapping lab ip-address vyatta@r1# set service dhcp-server shared-network-name dp0p1p1_pool subnet /24 static-mapping lab mac-address 00:15:c5:b3:2e:65 vyatta@r1# commit vyatta@r1# show service dhcp-server shared-network-name dp0p1p1_pool shared-network-name dp0p1p1_pool { subnet /24 { default-router dns-server start { stop static-mapping lab { ip-address mac-address 00:15:c5:b3:2e:65 Setting Up DHCP Servers for Failover The Vyatta system also provides a failover feature to allow for DHCP redundancy on a given subnet. In a failover configuration, two DHCP servers act as failover peers, with one of the peers designated as the primary and the other as the secondary. For DHCP failover to work, the following conditions must be met. Both peers must be Vyatta systems and must be running the same version of the Vyatta software. Each server must be configured to point to the other as the failover peer. The time on the servers must be exactly synchronized. The start-stop range must have at least one IP address for each subnet that has not been either excluded (by using the service dhcp-server shared-network-name <name> subnet <ipv4net> exclude <ipv4> command) or statically mapped (by using the service dhcp-server shared-network-name <name> subnet <ipv4net> static-mapping <mapname> command).

26 Chapter 1: DHCP DHCP Configuration 10 The system times should be synchronized before configuring DHCP failover. Use of NTP time synchronization is highly recommended. However, if difficulties arise because of incorrect system times, disable NTP, reset the times correctly, and then re-enable NTP. Note that DHCP leases are assigned only in failover configurations if proper communication is established between the two failover peers. If the configuration is incorrect (if, for example, one failover peer is configured but the other is not), DHCP leases are not dispersed. Also note that statically mapped addresses are not renewed by a failover server unless they are explicitly defined on that server by using the service dhcp-server shared-network-name <name> subnet <ipv4net> static-mapping <mapname> command command. Figure 1-3 shows the sample DHCP server failover configuration. Figure 1-3 DHCP server failover configuration DHCP servers DHCP clients Primary Secondary R1 R /24

27 Chapter 1: DHCP DHCP Configuration 11 To configure R1 as the primary DHCP server in this failover scenario, perform the following steps in configuration mode on R1. Example 1-5 Setting up DHCP failover on R1 Step Create the configuration node for DHCP1 on the /24 subnet. Specify the start and stop IP addresses for the pool. Specify the default router for DHCP1. Specify a DNS server for DHCP1. Specify the local IP address for the DHCP server for failover. Specify the IP address of the peer DHCP server for failover. Specify the role that the DHCP server plays in the failover group. Specify the name of the failover group. Commit the changes. Show the configuration. Command vyatta@r1# set service dhcp-server shared-network-name DHCP1 subnet /24 start stop vyatta@r1# set service dhcp-server shared-network-name DHCP1 subnet /24 default-router vyatta@r1# set service dhcp-server shared-network-name DHCP1 subnet /24 dns-server vyatta@r1# set service dhcp-server shared-network-name DHCP1 subnet /24 failover local-address vyatta@r1# set service dhcp-server shared-network-name DHCP1 subnet /24 failover peer-address vyatta@r1# set service dhcp-server shared-network-name DHCP1 subnet /24 failover status primary vyatta@r1# set service dhcp-server shared-network-name DHCP1 subnet /24 failover name FAILOVER vyatta@r1# commit vyatta@r1# show service dhcp-server shared-network-name DHCP1 shared-network-name DHCP1 { subnet /24 { default-router dns-server failover { local-address name FAILOVER peer-address status primary start { stop

28 Chapter 1: DHCP DHCP Configuration 12 To configure R2 as the secondary DHCP server in this failover scenario, perform the following steps in configuration mode on R2. Example 1-6 Setting up DHCP failover on R2 Step Create the configuration node for DHCP1 on the /24 subnet. Specify the start and stop IP addresses for the pool. Specify the default router for DHCP1. Specify a DNS server for DHCP1. Specify the local IP address for the DHCP server for failover. Specify the IP address of the peer DHCP server for failover. Specify the role that the DHCP server plays in the failover group. Specify the name of the failover group. Commit the changes. Show the configuration. Command vyatta@r2# set service dhcp-server shared-network-name DHCP1 subnet /24 start stop vyatta@r2# set service dhcp-server shared-network-name DHCP1 subnet /24 default-router vyatta@r2# set service dhcp-server shared-network-name DHCP1 subnet /24 dns-server vyatta@r2# set service dhcp-server shared-network-name DHCP1 subnet /24 failover local-address vyatta@r2# set service dhcp-server shared-network-name DHCP1 subnet /24 failover peer-address vyatta@r2# set service dhcp-server shared-network-name DHCP1 subnet /24 failover status secondary vyatta@r2# set service dhcp-server shared-network-name DHCP1 subnet /24 failover name FAILOVER vyatta@r2# commit vyatta@r2# show service dhcp-server shared-network-name DHCP1 shared-network-name DHCP1 { subnet /24 { default-router dns-server failover { local-address name FAILOVER peer-address status secondary start { stop