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 95134 www.brocade.com 408 333 8400
COPYRIGHT Copyright 2005 2015 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. 53-1003732-01
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............................................................... 1 DHCP Overview.................................................................................. 2 DHCP Configuration............................................................................... 3 Enabling the DHCP Server...................................................................... 3 Configuring DHCP Address Pools................................................................ 3 Configuring DHCPv4 Address Pools for Networks Directly Connected to the Router.................. 3 Configuring Address Pools for Networks Indirectly Connected to the Router........................ 7 Creating a Static Mapping...................................................................... 8 Setting Up DHCP Servers for Failover............................................................. 9 Setting Up DHCP Relay....................................................................... 13 Setting Additional DHCP Configuration Parameters................................................ 14 DHCP Commands................................................................................ 18 Chapter 2 DHCPv6........................................................... 126 DHCPv6 Overview.............................................................................. 127 DHCPv6 Configuration........................................................................... 127 Enabling the DHCPv6 Server.................................................................. 128 Configuring DHCPv6 Address Pools............................................................ 128 Configuring DHCPv6 Address Pools for Networks Directly Connected to the Router................ 128 Configuring DHCPv6 Address Pools for Networks Indirectly Connected to the Router............... 129 Creating a Static Mapping.................................................................... 131 Setting up DHCPv6 Relay..................................................................... 132 Setting up DHCPv6 Client.................................................................... 134 DHCPv6 Commands............................................................................. 135
iv Chapter 3 DNS.............................................................. 193 DNS Configuration.............................................................................. 194 DNS Overview.............................................................................. 194 System DNS............................................................................ 194 Dynamic DNS.......................................................................... 194 DNS Forwarding........................................................................ 195 DNS Configuration Examples................................................................. 195 Configuring Access to a Name Server....................................................... 196 Configuring Dynamic DNS................................................................ 196 Configuring DNS Forwarding.............................................................. 199 Statically Configured Entries and DNS Forwarding............................................ 201 DNS Commands................................................................................ 203 Chapter 4 Flow Monitoring.................................................... 234 Flow Monitoring Overview....................................................................... 234 Flow Monitoring Configuration................................................................... 237 Flow Monitoring Commands..................................................................... 240 Chapter 5 LLDP.............................................................. 251 LLDP Configuration............................................................................. 252 LLDP Overview............................................................................. 252 Configuring LLDP........................................................................... 252 Displaying LLDP Information.................................................................. 255 LLDP Commands............................................................................... 258 Chapter 6 NHRP............................................................. 274 NHRP Overview................................................................................ 275 NHRP and NBMA Networks.................................................................. 275 NHSs and NHCs............................................................................ 275 Supported Standards........................................................................ 276 NHRP Configuration............................................................................ 276 NHRP Commands............................................................................... 277 Chapter 7 sflow............................................................. 311 sflow Overview................................................................................ 312 Physical interfaces.......................................................................... 313 Packet-flow and port-counter sampling........................................................ 313 Packet-flow sampling.................................................................... 313 Counter-flow sampling................................................................... 313 Communication with collectors........................................................... 313 Supported sflow Types...................................................................... 313
v Configuring sflow.............................................................................. 314 sflow Commands............................................................................... 317 Chapter 8 TWAMP........................................................... 327 TWAMP Overview.............................................................................. 328 TWAMP Configuration.......................................................................... 330 Configuring the TWAMP Server............................................................... 331 Using twping to Measure IP Performance....................................................... 333 TWAMP Commands............................................................................ 334 List of Acronyms............................................................. 350
Quick List of Commands vi Use this list to help you quickly locate commands. clear flow-monitoring........................................................................... 249 clear sflow.................................................................................... 325 interfaces dataplane <dp_port> sflow.............................................................. 318 interfaces dataplane <interface> flow-monitoring selector <selector-name>............................. 241 interfaces tunnel <tunx> nhrp authentication <secret>............................................... 280 interfaces tunnel <tunx> nhrp dynamic-map nbma-domain <nbma-domain-name>........................ 282 interfaces tunnel <tunx> nhrp dynamic-map protocol-address <protocol-addr>/<prefix>................... 284 interfaces tunnel <tunx> nhrp holding-time <time>.................................................. 286 interfaces tunnel <tunx> nhrp map <protocol-addr>/<prefix> nbma-address <nbma-addr>................. 288 interfaces tunnel <tunx> nhrp map <protocol-addr>/<prefix> register................................... 290 interfaces tunnel <tunx> nhrp map <protocol-addr>/<prefix> register-no-unique......................... 292 interfaces tunnel <tunx> nhrp multicast parameters.................................................. 294 interfaces tunnel <tunx> nhrp multicast protocol-address <protocol-addr>............................... 296 interfaces tunnel <tunx> nhrp redirect............................................................. 298 interfaces tunnel <tunx> nhrp shortcut............................................................. 300 interfaces tunnel <tunx> nhrp shortcut-destination.................................................. 302 interfaces tunnel <tunx> nhrp shortcut-target <protocol-addr>/<prefix>................................. 304 interfaces tunnel <tunx> nhrp shortcut-target holding-time <time>..................................... 306 interfaces tunnel <tunx> nhrp.................................................................... 279 release dhcp interface <interface>................................................................. 22 release dhcpv6 interface <interface>.............................................................. 138 renew dhcp interface <interface>.................................................................. 23 renew dhcpv6 interface <interface>............................................................... 139 reset dhcp server lease ip <address>................................................................ 24 reset dhcp server leases.......................................................................... 25 reset dhcpv6 server leases....................................................................... 140 reset dns forwarding all......................................................................... 205 reset dns forwarding cache...................................................................... 206 reset ip nhrp flush tunnel........................................................................ 308 reset ip nhrp purge tunnel....................................................................... 309 restart dhcp relay-agent.......................................................................... 26 restart dhcp server.............................................................................. 27
vii restart dhcpv6 relay-agent....................................................................... 141 restart dhcpv6 server........................................................................... 142 service dhcp-relay interface <interface>............................................................. 30 service dhcp-relay server <ipv4>................................................................... 35 service dhcp-relay............................................................................... 28 service dhcp-relay relay-options................................................................... 32 service dhcp-server disabled <state>............................................................... 38 service dhcp-server dynamic-dns-update enable <state>............................................... 39 service dhcp-server global-parameters <params>..................................................... 41 service dhcp-server listento interface <dp_interface>................................................. 43 service dhcp-server shared-network-name <name> description <desc>................................... 48 service dhcp-server shared-network-name <name> disable............................................. 50 service dhcp-server shared-network-name <name> shared-network-parameters <params>.................. 51 service dhcp-server shared-network-name <name> subnet <ipv4net> bootfile-name <bootfile>.............. 55 service dhcp-server shared-network-name <name> subnet <ipv4net> bootfile-sever <addr>................. 57 service dhcp-server shared-network-name <name> subnet <ipv4net> client-prefix-length <prefix>............ 59 service dhcp-server shared-network-name <name> subnet <ipv4net> default-router <ipv4>................. 61 service dhcp-server shared-network-name <name> subnet <ipv4net> dns-server <ipv4>.................... 63 service dhcp-server shared-network-name <name> subnet <ipv4net> domain-name <domain-name>......... 65 service dhcp-server shared-network-name <name> subnet <ipv4net> exclude <ipv4>....................... 67 service dhcp-server shared-network-name <name> subnet <ipv4net> failover local-address <ipv4>........... 71 service dhcp-server shared-network-name <name> subnet <ipv4net> failover peer-address <ipv4>........... 75 service dhcp-server shared-network-name <name> subnet <ipv4net> failover status <status>................ 77 service dhcp-server shared-network-name <name> subnet <ipv4net> failover............................. 69 service dhcp-server shared-network-name <name> subnet <ipv4net> ip-forwarding enable <state>........... 79 service dhcp-server shared-network-name <name> subnet <ipv4net> lease <seconds>..................... 81 service dhcp-server shared-network-name <name> subnet <ipv4net> ntp-server <ipv4>.................... 83 service dhcp-server shared-network-name <name> subnet <ipv4net> pop-server <ipv4>.................... 85 service dhcp-server shared-network-name <name> subnet <ipv4net> server-identifier <ipv4>............... 87 service dhcp-server shared-network-name <name> subnet <ipv4net> smtp-server <ipv4>................... 89 service dhcp-server shared-network-name <name> subnet <ipv4net> start <ipv4> stop <ipv4>............... 91 service dhcp-server shared-network-name <name> subnet <ipv4net> static-mapping <mapname> disable..... 95 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>......................................................................................... 99
viii service dhcp-server shared-network-name <name> subnet <ipv4net> static-mapping <mapname> static-mappingparameters <params>........................................................................... 101 service dhcp-server shared-network-name <name> subnet <ipv4net> static-mapping <mapname>........... 93 service dhcp-server shared-network-name <name> subnet <ipv4net> static-route destination-subnet <ipv4net>... 103 service dhcp-server shared-network-name <name> subnet <ipv4net> static-route router <ipv4>............ 105 service dhcp-server shared-network-name <name> subnet <ipv4net> subnet-parameters <params>......... 107 service dhcp-server shared-network-name <name> subnet <ipv4net> tftp-server-name <servername>....... 109 service dhcp-server shared-network-name <name> subnet <ipv4net> time-offset <seconds>............... 111 service dhcp-server shared-network-name <name> subnet <ipv4net> time-server <ipv4>.................. 113 service dhcp-server shared-network-name <name> subnet <ipv4net> wins-server <ipv4>.................. 115 service dhcp-server shared-network-name <name> subnet <ipv4net> wpad-url <url>...................... 117 service dhcp-server shared-network-name <name> subnet <ipv4net>.................................... 53 service dhcp-server shared-network-name <name> authoritative <state>................................. 46 service dhcp-server shared-network-name <name> subnet <ipv4net> failover name <peer-name>............ 73 service dhcp-server shared-network-name <name>................................................... 45 service dhcp-server.............................................................................. 37 service dhcpv6-relay listen-interface <interface>.................................................... 144 service dhcpv6-relay listen-port <port>............................................................ 146 service dhcpv6-relay max-hop-count <count>....................................................... 147 service dhcpv6-relay upstream-interface <interface>................................................. 148 service dhcpv6-relay use-interface-id-option........................................................ 150 service dhcpv6-relay............................................................................ 143 service dhcpv6-server listento interface <dp_interface>.............................................. 152 service dhcpv6-server preference <preference>..................................................... 154 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>..... 163 service dhcpv6-server shared-network-name <name> subnet <ipv6net> address-range.................... 159 service dhcpv6-server shared-network-name <name> subnet <ipv6net> description <desc>................ 165 service dhcpv6-server shared-network-name <name> subnet <ipv6net> domain-search <domain>........... 167 service dhcpv6-server shared-network-name <name> subnet <ipv6net> lease-time....................... 169 service dhcpv6-server shared-network-name <name> subnet <ipv6net> name-server <ipv6>............... 171 service dhcpv6-server shared-network-name <name> subnet <ipv6net> nis-domain <nis-domain-name>..... 173 service dhcpv6-server shared-network-name <name> subnet <ipv6net> nisplus-domain <nisplus-domain-name>.. 175 service dhcpv6-server shared-network-name <name> subnet <ipv6net> nisplus-server <ipv6>.............. 177 service dhcpv6-server shared-network-name <name> subnet <ipv6net> nis-server <ipv6>.................. 179
ix service dhcpv6-server shared-network-name <name> subnet <ipv6net> sip-server-address <ipv6>........... 181 service dhcpv6-server shared-network-name <name> subnet <ipv6net> sip-server-name <sip-server-name>.. 183 service dhcpv6-server shared-network-name <name> subnet <ipv6net> sntp-server-address <ipv6>......... 185 service dhcpv6-server shared-network-name <name> subnet <ipv6net> static-mapping <mapping-name>.... 187 service dhcpv6-server shared-network-name <name> subnet <ipv6net>................................. 157 service dhcpv6-server shared-network-name <name>................................................ 155 service dhcpv6-server........................................................................... 151 service dns dynamic interface <interface> service <service> host-name <hostname>...................... 211 service dns dynamic interface <interface> service <service> login <service-login>......................... 213 service dns dynamic interface <interface> service <service> password <service-password>................. 215 service dns dynamic interface <interface> service <service> server <addr>............................... 217 service dns dynamic interface <interface> service <service>........................................... 209 service dns dynamic interface <interface>.......................................................... 207 service dns forwarding cache-size <size>........................................................... 219 service dns forwarding dhcp <interface>........................................................... 220 service dns forwarding listen-on <interface>........................................................ 222 service dns forwarding name-server <ipv4>......................................................... 224 service dns forwarding system.................................................................... 226 service flow-monitoring exporter udp-collector address <ip-address>................................... 243 service flow-monitoring exporter udp-collector port <udp-port>....................................... 245 service flow-monitoring selector <selector-name> randomly out-of <num-of-packets>..................... 247 service lldp interface <interface> location civic-based................................................ 260 service lldp interface <interface> location coordinate-based........................................... 263 service lldp interface <interface> location elin <phone-num>.......................................... 265 service lldp legacy-protocols <protocol>............................................................ 267 service lldp management-address <ipv4>........................................................... 269 service lldp.................................................................................... 259 service sflow agent-address <IPv4-or-IPv6>......................................................... 319 service sflow polling-interval <polling_rate>........................................................ 323 service sflow sampling-rate <sampling_rate>........................................................ 322 service sflow server-address <IPv4-or-IPv6> server-port <port>........................................ 320 service twamp server client-list <ip-address>........................................................ 336 service twamp server dscp-value <value>........................................................... 337 service twamp server maximum-connections <count>................................................ 338 service twamp server maximum-sessions-per-connection <count>...................................... 339 service twamp server mode <authentication-mode>................................................. 340
x service twamp server port <port-number>.......................................................... 341 service twamp server test-inactivity-timeout <seconds>.............................................. 343 service twamp server user <username> password <pwd>............................................. 344 service twamp server........................................................................... 335 service twamp server server-inactivity-timeout <seconds>............................................ 342 show dhcp client leases......................................................................... 119 show dhcp server leases......................................................................... 122 show dhcp server statistics....................................................................... 124 show dhcpv6 client leases....................................................................... 189 show dhcpv6 relay-agent status................................................................... 190 show dhcpv6 server leases....................................................................... 191 show dhcpv6 server status....................................................................... 192 show dns dynamic status........................................................................ 228 show dns forwarding nameservers................................................................ 230 show dns forwarding statistics.................................................................... 231 show flow-monitoring........................................................................... 250 show ip nhrp tunnel............................................................................ 310 show lldp neighbors............................................................................ 270 show service twamp server session [all client <ip-address> summary]................................ 345 show sflow.................................................................................... 324 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>]........................................................................ 348 update dns dynamic interface <interface>.......................................................... 233
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.............................................................. 3 Example 1-2 Configuring DHCP address pools......................................................... 4 Example 1-3 Configuring DHCP address pools......................................................... 7 Example 1-4 Creating a static mapping............................................................... 9 Example 1-5 Setting up DHCP failover on R1......................................................... 11 Example 1-6 Setting up DHCP failover on R2......................................................... 12 Example 1-7 Setting up DHCP relay................................................................. 14 Example 1-8 Setting up DHCP server with additional parameters........................................ 16 Example 1-9 Displaying DHCP information for all interfaces configured as DHCP clients.................... 121 Example 1-10 Displaying all current DHCP lease information........................................... 123 Example 1-11 Displaying all DHCP server statistics.................................................... 124 Example 2-1 Enabling the DHCPv6 service.......................................................... 128 Example 2-2 Configuring a DHCPv6 address pool..................................................... 129 Example 2-3 Configuring a DHCPv6 address pool..................................................... 130 Example 2-4 Creating a static mapping............................................................. 132 Example 2-5 Setting up DHCPv6 relay.............................................................. 133 Example 2-6 Setting up a DHCPv6 client on an Ethernet interface....................................... 134 Example 3-1 Configuring static access to a DNS name server.......................................... 196 Example 3-2 Setting up dynamic DNS.............................................................. 198 Example 3-3 Setting up DNS forwarding............................................................ 200 Example 3-4 Setting up static entries.............................................................. 201 Example 3-5 Displaying update status for hosts configured for DDNS................................... 228 Example 3-6 Displaying the name servers being used for DNS forwarding................................ 230 Example 3-7 Displaying DNS forwarding statistics.................................................... 231 Example 4-1 Configuring the Flow Monitoring service................................................ 237 Example 5-1 Enabling LLDP on a system............................................................ 252 Example 5-2 Configuring a civic-based location for LLDP.............................................. 253 Example 5-3 Configuring the physical coordinates of a system......................................... 254
xii Example 5-4 Showing LLDP neighbors.............................................................. 255 Example 5-5 Showing detailed information on LLDP neighbors.......................................... 255 Example 5-6 Displaying a summary of link layer neighbors............................................. 270 Example 5-7 Displaying details of link layer neighbors................................................. 271 Example 6-1 Removing all non-permanent entries for the tun0 tunnel.................................. 308 Example 6-2 Removing and reregistering all NHRP entries for the tun0 tunnel............................ 309 Example 6-3 Displaying NHRP information about the tun0 tunnel...................................... 310 Example 7-1 Configuring sflow................................................................... 314 Example 7-2 Displaying sflow configuration information and usage statistics............................. 324 Example 7-3 Clearing the collected sflow statistics.................................................. 325 Example 8-1 Configuring the TWAMP service........................................................ 331 Example 8-2 Configuring the TWAMP service........................................................ 333 Example 8-3 Displaying the details of all current TWAMP sessions....................................... 345 Example 8-4 Displaying the information for a specific TWAMP session................................... 346 Example 8-5 Displaying a summary of current TWAMP sessions........................................ 347
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
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
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. 126 193 234 251 274 311 327 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.
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 1 65535, 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: http://www.brocade.com/5600documentation http://www.brocade.com/products/all/network-functions-virtualization/product-details/5 600-vrouter/index.page
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
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.
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 172.16.0.0/24 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 172.16.0.34. dp0p1p2_30_pool. This address pool serves the 10.10.30.0/24 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 10.10.40.34, which is directly connected to dp0p1p2.40 (that is, dp0p1p2 virtual interface [vif] 40).
Chapter 1: DHCP DHCP Configuration 4 dp0p1p2_40_pool. This address pool serves the 10.10.40.0/24 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 10.10.40.34, 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 172.16.0.0/24 Address Pool: dp0p1p1_pool Subnet: 172.16.0.0/24 Start Address: 172.16.0.100 Stop Address: 172.16.0.199 Lease (Seconds): 86,400 DNS Server: 172.16.0.34 dp0p1p1.65 R1 dp0p1p2.65 dp0p1p2 vif 40.65 10.10.30.0/24 10.10.40.0/24 Address Pool: dp0p1p2_30_pool Subnet: 10.10.30.0/24 Start Address: 10.10.30.100 Stop Address: 10.10.30.199 Lease (Seconds): 86,400 DNS Server: 10.10.40.34 Address Pool: dp0p1p2_40_pool Subnet: 10.10.40.0/24 Start Address: 10.10.40.100 Stop Address: 10.10.40.199 Lease (Seconds): 86,400 DNS Server: 10.10.40.34 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 172.16.0.0/24 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 172.16.0.0/24 start 172.16.0.100 stop 172.16.0.199 vyatta@r1# set service dhcp-server shared-network-name dp0p1p1_pool subnet 172.16.0.0/24 default-router 172.16.0.65
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 10.10.30.0/24 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 10.10.40.0/24 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 172.16.0.0/24 dns-server 172.16.0.34 vyatta@r1# set service dhcp-server shared-network-name dp0p1p2_30_pool subnet 10.10.30.0/24 start 10.10.30.100 stop 10.10.30.199 vyatta@r1# set service dhcp-server shared-network-name dp0p1p2_30_pool subnet 10.10.30.0/24 default-router 10.10.30.65 vyatta@r1# set service dhcp-server shared-network-name dp0p1p2_30_pool subnet 10.10.30.0/24 dns-server 10.10.40.34 vyatta@r1# set service dhcp-server shared-network-name dp0p1p2_40_pool subnet 10.10.40.0/24 start 10.10.40.100 stop 10.10.40.199 vyatta@r1# set service dhcp-server shared-network-name dp0p1p2_40_pool subnet 10.10.40.0/24 default-router 10.10.40.65 vyatta@r1# set service dhcp-server shared-network-name dp0p1p2_40_pool subnet 10.10.40.0/24 dns-server 10.10.40.34 vyatta@r1# commit
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 172.16.0.0/24 { default-router 172.16.0.65 dns-server 172.16.0.34 start 172.16.0.100 { stop 172.16.0.199 shared-network-name dp0p1p2_30_pool { subnet 10.10.30.0/24 { default-router 10.10.30.65 dns-server 10.10.40.34 start 10.10.30.100 { stop 10.10.30.199 shared-network-name dp0p1p2_40_pool { subnet 10.10.40.0/24 { default-router 10.10.40.65 dns-server 10.10.40.34 start 10.10.40.100 { stop 10.10.40.199 vyatta@r1# show interfaces dataplane dp0p1p1 { address 172.16.0.65/24 hw-id 00:0c:29:42:05:2b dataplane dp0p1p2 { address 10.10.30.65/24 hw-id 00:0c:29:42:05:35 vif 40 { address 10.10.40.65/24
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 192.168.1.0/24 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 172.16.0.34. 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
Chapter 1: DHCP DHCP Configuration 8 Example 1-3 Configuring DHCP address pools (Continued) Create a shared network and associate it with the 192.168.1.0/24 subnet. Show the configuration. Show the interface configuration. Commit the changes. vyatta@r1# set service dhcp-server shared-network-name dp0p1p1_pool2 subnet 192.168.1.0/24 vyatta@r1# show service dhcp-server dhcp-server { listento { interface dp0p1p1 shared-network-name dp0p1p1_pool2 { subnet 192.168.1.0/24 { dns-server 192.168.1.100 lease 86400 start 192.168.1.100 { stop 192.168.1.199 vyatta@r1# show interfaces interfaces { dataplane dp0p1p1 { address 172.16.0.0/24 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 172.16.0.101 IP address to the device with a MAC address of 00:15:c5:b3:2e:65.
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 172.16.0.0/24 static-mapping lab ip-address 172.16.0.101 vyatta@r1# set service dhcp-server shared-network-name dp0p1p1_pool subnet 172.16.0.0/24 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 172.16.0.0/24 { default-router 172.16.0.65 dns-server 172.16.0.34 start 172.16.0.100 { stop 172.16.0.199 static-mapping lab { ip-address 172.16.0.101 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).
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 R2.1.2 192.168.42.0/24
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 192.168.42.0/24 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 192.168.42.0/24 start 192.168.42.100 stop 192.168.42.199 vyatta@r1# set service dhcp-server shared-network-name DHCP1 subnet 192.168.42.0/24 default-router 192.168.42.254 vyatta@r1# set service dhcp-server shared-network-name DHCP1 subnet 192.168.42.0/24 dns-server 192.168.42.253 vyatta@r1# set service dhcp-server shared-network-name DHCP1 subnet 192.168.42.0/24 failover local-address 192.168.42.1 vyatta@r1# set service dhcp-server shared-network-name DHCP1 subnet 192.168.42.0/24 failover peer-address 192.168.42.2 vyatta@r1# set service dhcp-server shared-network-name DHCP1 subnet 192.168.42.0/24 failover status primary vyatta@r1# set service dhcp-server shared-network-name DHCP1 subnet 192.168.42.0/24 failover name FAILOVER vyatta@r1# commit vyatta@r1# show service dhcp-server shared-network-name DHCP1 shared-network-name DHCP1 { subnet 192.168.42.0/24 { default-router 192.168.42.254 dns-server 192.168.42.253 failover { local-address 192.168.42.1 name FAILOVER peer-address 192.168.42.2 status primary start 192.168.42.100 { stop 192.168.42.199
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 192.168.42.0/24 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 192.168.42.0/24 start 192.168.42.100 stop 192.168.42.199 vyatta@r2# set service dhcp-server shared-network-name DHCP1 subnet 192.168.42.0/24 default-router 192.168.42.254 vyatta@r2# set service dhcp-server shared-network-name DHCP1 subnet 192.168.42.0/24 dns-server 192.168.42.253 vyatta@r2# set service dhcp-server shared-network-name DHCP1 subnet 192.168.42.0/24 failover local-address 192.168.42.2 vyatta@r2# set service dhcp-server shared-network-name DHCP1 subnet 192.168.42.0/24 failover peer-address 192.168.42.1 vyatta@r2# set service dhcp-server shared-network-name DHCP1 subnet 192.168.42.0/24 failover status secondary vyatta@r2# set service dhcp-server shared-network-name DHCP1 subnet 192.168.42.0/24 failover name FAILOVER vyatta@r2# commit vyatta@r2# show service dhcp-server shared-network-name DHCP1 shared-network-name DHCP1 { subnet 192.168.42.0/24 { default-router 192.168.42.254 dns-server 192.168.42.253 failover { local-address 192.168.42.2 name FAILOVER peer-address 192.168.42.1 status secondary start 192.168.42.100 { stop 192.168.42.199