Debian系统dhcp server配置— kea

冷不防 2022-10-08 14:30 453阅读 0赞

**记录一次kea-dhcp4server的配置**

系统及架构：  
Linux Matrix\_061001 5.10.42-yocto-standard \#1 Thu Jun 3 07:00:52 UTC 2021 armv7l armv7l armv7l GNU/Linux

参考文章：  
[https://kea.readthedocs.io/en/kea-1.8.0/arm/config.html][https_kea.readthedocs.io_en_kea-1.8.0_arm_config.html]  
[https://blog.csdn.net/z475382220/article/details/78844227][https_blog.csdn.net_z475382220_article_details_78844227]

首先安装kea-dhcpserver

apt-get update
    apt-get install kea

记录kea-dhcp4.conf配置

cat  /etc/kea/kea-dhcp4.conf

// This is a basic configuration for the Kea DHCPv4 server. Subnet declarations
    // are mostly commented out and no interfaces are listed. Therefore, the servers
    // will not listen or respond to any queries.
    // The basic configuration must be extended to specify interfaces on which
    // the servers should listen. There are a number of example options defined.
    // These probably don't make any sense in your network. Make sure you at least
    // update the following, before running this example in your network:
    // - change the network interface names
    // - change the subnets to match your actual network
    // - change the option values to match your network
    //
    // This is just a very basic configuration. Kea comes with large suite (over 30)
    // of configuration examples and extensive Kea User's Guide. Please refer to
    // those materials to get better understanding of what this software is able to
    // do. Comments in this configuration file sometimes refer to sections for more
    // details. These are section numbers in Kea User's Guide. The version matching
    // your software should come with your Kea package, but it is also available
    // in ISC's Knowledgebase (https://kb.isc.org/docs/kea-administrator-reference-manual; the direct link for
    // the stable version is https://kea.readthedocs.io/).
    //
    // This configuration file contains only DHCPv4 server's configuration.
    // If configurations for other Kea services are also included in this file they
    // are ignored by the DHCPv4 server.
    {
    
    // DHCPv4 configuration starts here. This section will be read by DHCPv4 server
    // and will be ignored by other components.
    "Dhcp4": {
        // Add names of your network interfaces to listen on.
        "interfaces-config": {
            // See section 8.2.4 for more details. You probably want to add just
            // interface name (e.g. "eth0" or specific IPv4 address on that
            // interface name (e.g. "eth0/192.0.2.1").
            //"interfaces": [ ]
            "interfaces": ["eth0"],
    
            // Kea DHCPv4 server by default listens using raw sockets. This ensures
            // all packets, including those sent by directly connected clients
            // that don't have IPv4 address yet, are received. However, if your
            // traffic is always relayed, it is often better to use regular
            // UDP sockets. If you want to do that, uncomment this line:
            // "dhcp-socket-type": "udp"
            "dhcp-socket-type": "raw"
        },
    
        // Kea support control channel, which is a way to receive management
        // commands while the server is running. This is a Unix domain socket that
        // receives commands formatted in JSON, e.g. config-set (which sets new
        // configuration), config-reload (which tells Kea to reload its
        // configuration from file), statistic-get (to retrieve statistics) and many
        // more. For detailed description, see Sections 8.8, 16 and 15.
        "control-socket": {
        
            "socket-type": "unix",
            "socket-name": "/tmp/kea4-ctrl-socket"
        },
    
        // Use Memfile lease database backend to store leases in a CSV file.
        // Depending on how Kea was compiled, it may also support SQL databases
        // (MySQL and/or PostgreSQL) and even Cassandra. Those database backends
        // require more parameters, like name, host and possibly user and password.
        // There are dedicated examples for each backend. See Section 7.2.2 "Lease
        // Storage" for details.
        "lease-database": {
        
            // Memfile is the simplest and easiest backend to use. It's a in-memory
            // C++ database that stores its state in CSV file.
            "type": "memfile",
            //"persist": ture ,
            //"name": "/var/lib/kea/dhcp4.leases"
            "lfc-interval": 3600
        },
    
        // Kea allows storing host reservations in a database. If your network is
        // small or you have few reservations, it's probably easier to keep them
        // in the configuration file. If your network is large, it's usually better
        // to use database for it. To enable it, uncomment the following:
        // "hosts-database": {
        //     "type": "mysql",
        //     "name": "kea",
        //     "user": "kea",
        //     "password": "kea",
        //     "host": "localhost",
        //     "port": 3306
        // },
        // See Section 7.2.3 "Hosts storage" for details.
    
        // Setup reclamation of the expired leases and leases affinity.
        // Expired leases will be reclaimed every 10 seconds. Every 25
        // seconds reclaimed leases, which have expired more than 3600
        // seconds ago, will be removed. The limits for leases reclamation
        // are 100 leases or 250 ms for a single cycle. A warning message
        // will be logged if there are still expired leases in the
        // database after 5 consecutive reclamation cycles.
        "expired-leases-processing": {
            "reclaim-timer-wait-time": 10,
            "flush-reclaimed-timer-wait-time": 25,
            "hold-reclaimed-time": 3600,
            "max-reclaim-leases": 100,
            "max-reclaim-time": 250,
            "unwarned-reclaim-cycles": 5
        },
    
        // Global timers specified here apply to all subnets, unless there are
        // subnet specific values defined in particular subnets.
        //"renew-timer": 900,
        //"rebind-timer": 1800,
        //"valid-lifetime": 3600,
        "renew-timer": 1000,
        "rebind-timer": 2000,
        "valid-lifetime": 4000,
    
        // Many additional parameters can be specified here:
        // - option definitions (if you want to define vendor options, your own
        //                       custom options or perhaps handle standard options
        //                       that Kea does not support out of the box yet)
        // - client classes
        // - hooks
        // - ddns information (how the DHCPv4 component can reach a DDNS daemon)
        //
        // Some of them have examples below, but there are other parameters.
        // Consult Kea User's Guide to find out about them.
    
        // These are global options. They are going to be sent when a client
        // requests them, unless overwritten with values in more specific scopes.
        // The scope hierarchy is:
        // - global (most generic, can be overwritten by class, subnet or host)
        // - class (can be overwritten by subnet or host)
        // - subnet (can be overwritten by host)
        // - host (most specific, overwrites any other scopes)
        //
        // Not all of those options make sense. Please configure only those that
        // are actually useful in your network.
        //
        // For a complete list of options currently supported by Kea, see
        // Section 7.2.8 "Standard DHCPv4 Options". Kea also supports
        // vendor options (see Section 7.2.10) and allows users to define their
        // own custom options (see Section 7.2.9).
        "option-data": [
            // When specifying options, you typically need to specify
            // one of (name or code) and data. The full option specification
            // covers name, code, space, csv-format and data.
            // space defaults to "dhcp4" which is usually correct, unless you
            // use encapsulate options. csv-format defaults to "true", so
            // this is also correct, unless you want to specify the whole
            // option value as long hex string. For example, to specify
            // domain-name-servers you could do this:
            // {
        
            //     "name": "domain-name-servers",
            //     "code": 6,
            //     "csv-format": "true",
            //     "space": "dhcp4",
            //     "data": "192.0.2.1, 192.0.2.2"
            // }
            // but it's a lot of writing, so it's easier to do this instead:
            {
        
                "name": "domain-name-servers",
                //"data": "192.0.2.1, 192.0.2.2"
                "data": "221.11.1.67, 114.114.114.114"
            },
    
            // Typically people prefer to refer to options by their names, so they
            // don't need to remember the code names. However, some people like
            // to use numerical values. For example, option "domain-name" uses
            // option code 15, so you can reference to it either by
            // "name": "domain-name" or "code": 15.
            {
                "code": 15,
                "data": "example.org"
            },
    
            // Domain search is also a popular option. It tells the client to
            // attempt to resolve names within those specified domains. For
            // example, name "foo" would be attempted to be resolved as
            // foo.mydomain.example.com and if it fails, then as foo.example.com
            {
                "name": "domain-search",
                "data": "mydomain.example.com, example.com"
            },
    
            // String options that have a comma in their values need to have
            // it escaped (i.e. each comma is preceded by two backslashes).
            // That's because commas are reserved for separating fields in
            // compound options. At the same time, we need to be conformant
            // with JSON spec, that does not allow "\,". Therefore the
            // slightly uncommon double backslashes notation is needed.
    
            // Legal JSON escapes are \ followed by "\/bfnrt character
            // or \u followed by 4 hexadecimal numbers (currently Kea
            // supports only \u0000 to \u00ff code points).
            // CSV processing translates '\\' into '\' and '\,' into ','
            // only so for instance '\x' is translated into '\x'. But
            // as it works on a JSON string value each of these '\'
            // characters must be doubled on JSON input.
            {
                "name": "boot-file-name",
                "data": "EST5EDT4\\,M3.2.0/02:00\\,M11.1.0/02:00"
            },
    
            // Options that take integer values can either be specified in
            // dec or hex format. Hex format could be either plain (e.g. abcd)
            // or prefixed with 0x (e.g. 0xabcd).
            {
                "name": "default-ip-ttl",
                "data": "0xf0"
            }
    
            // Note that Kea provides some of the options on its own. In particular,
            // it sends IP Address lease type (code 51, based on valid-lifetime
            // parameter, Subnet mask (code 1, based on subnet definition), Renewal
            // time (code 58, based on renew-timer parameter), Rebind time (code 59,
            // based on rebind-timer parameter).
        ],
    
        // Other global parameters that can be defined here are option definitions
        // (this is useful if you want to use vendor options, your own custom
        // options or perhaps handle options that Kea does not handle out of the box
        // yet).
    
        // You can also define classes. If classes are defined, incoming packets
        // may be assigned to specific classes. A client class can represent any
        // group of devices that share some common characteristic, e.g. Windows
        // devices, iphones, broken printers that require special options, etc.
        // Based on the class information, you can then allow or reject clients
        // to use certain subnets, add special options for them or change values
        // of some fixed fields.
        "client-classes": [
            {
                // This specifies a name of this class. It's useful if you need to
                // reference this class.
                "name": "voip",
    
                // This is a test. It is an expression that is being evaluated on
                // each incoming packet. It is supposed to evaluate to either
                // true or false. If it's true, the packet is added to specified
                // class. See Section 12 for a list of available expressions. There
                // are several dozens. Section 8.2.14 for more details for DHCPv4
                // classification and Section 9.2.19 for DHCPv6.
                "test": "substring(option[60].hex,0,6) == 'Aastra'",
    
                // If a client belongs to this class, you can define extra behavior.
                // For example, certain fields in DHCPv4 packet will be set to
                // certain values.
                // "next-server": "192.0.2.254",
                "next-server": "192.168.11.254",
                "server-hostname": "hal9000",
                "boot-file-name": "/dev/null"
    
                // You can also define option values here if you want devices from
                // this class to receive special options.
            }
        ],
    
        // Another thing possible here are hooks. Kea supports a powerful mechanism
        // that allows loading external libraries that can extract information and
        // even influence how the server processes packets. Those libraries include
        // additional forensic logging capabilities, ability to reserve hosts in
        // more flexible ways, and even add extra commands. For a list of available
        // hook libraries, see https://gitlab.isc.org/isc-projects/kea/wikis/Hooks-available.
        //"hooks-libraries": [
        //  {
        //      // Forensic Logging library generates forensic type of audit trail
        //      // of all devices serviced by Kea, including their identifiers
        //      // (like MAC address), their location in the network, times
        //      // when they were active etc.
        //      // Replace $libdir with real library path /usr/lib or /usr/lib64
        //      "library": "$libdir/kea/hooks/libdhcp_legal_log.so"
        //      "parameters": {
        //          "path": "/var/lib/kea",
        //          "base-name": "kea-forensic4"
        //      }
        //  },
        //  {
        //      // Flexible identifier (flex-id). Kea software provides a way to
        //      // handle host reservations that include addresses, prefixes,
        //      // options, client classes and other features. The reservation can
        //      // be based on hardware address, DUID, circuit-id or client-id in
        //      // DHCPv4 and using hardware address or DUID in DHCPv6. However,
        //      // there are sometimes scenario where the reservation is more
        //      // complex, e.g. uses other options that mentioned above, uses part
        //      // of specific options or perhaps even a combination of several
        //      // options and fields to uniquely identify a client. Those scenarios
        //      // are addressed by the Flexible Identifiers hook application.
        //      // Replace $libdir with real library path /usr/lib or /usr/lib64
        //      "library": "$libdir/kea/hooks/libdhcp_flex_id.so",
        //      "parameters": {
        //          "identifier-expression": "substring(relay6[0].option[18],0,8)"
        //      }
        //  }
        //],
    
        // Below an example of a simple IPv4 subnet declaration. Uncomment to enable
        // it. This is a list, denoted with [ ], of structures, each denoted with
        // { }. Each structure describes a single subnet and may have several
        // parameters. One of those parameters is "pools" that is also a list of
        // structures.
        "subnet4": [
            {
                // This defines the whole subnet. Kea will use this information to
                // determine where the clients are connected. This is the whole
                // subnet in your network. This is mandatory parameter for each
                // subnet.
                //"subnet": "192.0.2.0/24",
                "subnet": "192.168.11.0/24",
    
                // Pools define the actual part of your subnet that is governed
                // by Kea. Technically this is optional parameter, but it's
                // almost always needed for DHCP to do its job. If you omit it,
                // clients won't be able to get addresses, unless there are
                // host reservations defined for them.
                //"pools": [ { "pool": "192.0.2.200 - 192.0.2.210" } ],
                "pools": [ { "pool": "192.168.11.200 - 192.168.11.205" } ],
    
                // These are options that are subnet specific. In most cases,
                // you need to define at least routers option, as without this
                // option your clients will not be able to reach their default
                // gateway and will not have Internet connectivity.
                "option-data": [
                    {
                        // For each IPv4 subnet you most likely need to specify at
                        // least one router.
                        "name": "routers",
                        //"data": "192.0.2.1"
                        "data": "192.168.11.46"
                    }
                ],
                // Kea offers host reservations mechanism. Kea supports reservations
                // by several different types of identifiers: hw-address
                // (hardware/MAC address of the client), duid (DUID inserted by the
                // client), client-id (client identifier inserted by the client) and
                // circuit-id (circuit identifier inserted by the relay agent).
                //
                // Kea also support flexible identifier (flex-id), which lets you
                // specify an expression that is evaluated for each incoming packet.
                // Resulting value is then used for as an identifier.
                //
                // Note that reservations are subnet-specific in Kea. This is
                // different than ISC DHCP. Keep that in mind when migrating
                // your configurations.
                "reservations": [
    
                    // This is a reservation for a specific hardware/MAC address.
                    // It's a rather simple reservation: just an address and nothing
                    // else.
                    {
                        "hw-address": "1a:1b:1c:1d:1e:1f",
                        //"ip-address": "192.0.2.201"
                        "ip-address": "192.168.11.201"
                    },
    
                    // This is a reservation for a specific client-id. It also shows
                    // the this client will get a reserved hostname. A hostname can
                    // be defined for any identifier type, not just client-id.
                    {
                        "client-id": "01:11:22:33:44:55:66",
                        //"ip-address": "192.0.2.202",
                        "ip-address": "192.168.11.202",
                        "hostname": "special-snowflake"
                    },
    
                    // The third reservation is based on DUID. This reservation defines
                    // a special option values for this particular client. If the
                    // domain-name-servers option would have been defined on a global,
                    // subnet or class level, the host specific values take preference.
                    {
                        "duid": "01:02:03:04:05",
                        //"ip-address": "192.0.2.203",
                        "ip-address": "192.168.11.203",
                        "option-data": [ {
                            "name": "domain-name-servers",
                            "data": "10.1.1.202, 10.1.1.203"
                        } ]
                    },
    
                    // The fourth reservation is based on circuit-id. This is an option
                    // inserted by the relay agent that forwards the packet from client
                    // to the server.  In this example the host is also assigned vendor
                    // specific options.
                    //
                    // When using reservations, it is useful to configure
                    // reservation-mode (subnet specific parameter) and
                    // host-reservation-identifiers (global parameter).
                    {
                        "client-id": "01:12:23:34:45:56:67",
                        //"ip-address": "192.0.2.204",
                        "ip-address": "192.168.11.204",
                        "option-data": [
                            {
                                "name": "vivso-suboptions",
                                "data": "4491"
                            },
                            {
                                "name": "tftp-servers",
                                "space": "vendor-4491",
                                "data": "10.1.1.202, 10.1.1.203"
                            }
                        ]
                    },
                    // This reservation is for a client that needs specific DHCPv4
                    // fields to be set. Three supported fields are next-server,
                    // server-hostname and boot-file-name
                    {
                        "client-id": "01:0a:0b:0c:0d:0e:0f",
                        //"ip-address": "192.0.2.205",
                        //"next-server": "192.0.2.1",
                        "ip-address": "192.168.11.205",
                        "next-server": "192.168.11.1",
                        "server-hostname": "hal9000",
                        "boot-file-name": "/dev/null"
                    },
                    // This reservation is using flexible identifier. Instead of
                    // relying on specific field, sysadmin can define an expression
                    // similar to what is used for client classification,
                    // e.g. substring(relay[0].option[17],0,6). Then, based on the
                    // value of that expression for incoming packet, the reservation
                    // is matched. Expression can be specified either as hex or
                    // plain text using single quotes.
                    //
                    // quotes.
                    //
                    // Note: flexible identifier requires flex_id hook library to be
                    // loaded to work.
                    {
                        "flex-id": "'s0mEVaLue'",
                        //"ip-address": "192.0.2.206"
                        "ip-address": "192.168.11.206"
                    }
                    // You can add more reservations here.
                ]
                // You can add more subnets there.
            }
        ],
    
        // There are many, many more parameters that DHCPv4 server is able to use.
        // They were not added here to not overwhelm people with too much
        // information at once.
    
    // Logging configuration starts here. Kea uses different loggers to log various
    // activities. For details (e.g. names of loggers), see Chapter 18.
        "loggers": [
        {
            // This section affects kea-dhcp4, which is the base logger for DHCPv4
            // component. It tells DHCPv4 server to write all log messages (on
            // severity INFO or more) to a file.
            //"name": "kea-dhcp4",
            "name": "*",
            "output_options": [
                {
                    // Specifies the output file. There are several special values
                    // supported:
                    // - stdout (prints on standard output)
                    // - stderr (prints on standard error)
                    // - syslog (logs to syslog)
                    // - syslog:name (logs to syslog using specified name)
                    // Any other value is considered a name of a time
                    "output": "/var/log/kea-dhcp4.log"
    
                    // Shorter log pattern suitable for use with systemd,
                    // avoids redundant information
                    // "pattern": "%-5p %m\n"
    
                    // This governs whether the log output is flushed to disk after
                    // every write.
                    // "flush": false,
    
                    // This specifies the maximum size of the file before it is
                    // rotated.
                    // "maxsize": 1048576,
    
                    // This specifies the maximum number of rotated files to keep.
                    // "maxver": 8
                }
            ],
            // This specifies the severity of log messages to keep. Supported values
            // are: FATAL, ERROR, WARN, INFO, DEBUG
            //"severity": "INFO",
            "severity": "DEBUG",
    
            // If DEBUG level is specified, this value is used. 0 is least verbose,
            // 99 is most verbose. Be cautious, Kea can generate lots and lots
            // of logs if told to do so.
            "debuglevel": 0
        }
      ]
    }
    }

配置eth0 ip地址

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 192.168.11.46  netmask 255.255.255.0  broadcast 0.0.0.0
            inet6 fe80::213:48ff:fe03:ccc4  prefixlen 64  scopeid 0x20<link>
            ether 00:13:48:03:cc:c4  txqueuelen 1000  (Ethernet)
            RX packets 8  bytes 1006 (1006.0 B)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 2  bytes 188 (188.0 B)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
            device interrupt 39  base 0x8000

启动kea-dhcp4server

/etc/init.d/kea-dhcp4-server restart
    或
    keactrl start

使用过程中WARN记录：

2021-08-17 15:53:53.487 INFO  [kea-dhcp4.dhcp4/1050.3069653008] DHCP4_STARTED Kea DHCPv4 server version 1.8.2 started
    2021-08-17 15:54:05.832 WARN  [kea-dhcp4.alloc-engine/1050.3069653008] ALLOC_ENGINE_V4_ALLOC_FAIL [hwtype=1 48:2a:e3:0b:78:35], cid=[01:48:2a:e3:0b:78:35], tid=0xa0fbb56d: failed to allocate an IPv4 address after 6 attempt(s)
    2021-08-17 15:54:05.844 WARN  [kea-dhcp4.alloc-engine/1050.3069653008] ALLOC_ENGINE_V4_ALLOC_FAIL_CLASSES [hwtype=1 48:2a:e3:0b:78:35], cid=[01:48:2a:e3:0b:78:35], tid=0xa0fbb56d: Failed to allocate an IPv4 address for client with classes: ALL, VENDOR_CLASS_MSFT 5.0, UNKNOWN

解决方法：增大地址池范围 - - [https://kea.readthedocs.io/en/latest/kea-messages.html][https_kea.readthedocs.io_en_latest_kea-messages.html]

“pools”: \[ \{ “pool”: “192.168.11.200 - 192.168.11.205” \} \],  
改为：  
“pools”: \[ \{ “pool”: “192.168.11.100 - 192.168.11.220” \} \],

[https_kea.readthedocs.io_en_kea-1.8.0_arm_config.html]: https://kea.readthedocs.io/en/kea-1.8.0/arm/config.html
[https_blog.csdn.net_z475382220_article_details_78844227]: https://blog.csdn.net/z475382220/article/details/78844227
[https_kea.readthedocs.io_en_latest_kea-messages.html]: https://kea.readthedocs.io/en/latest/kea-messages.html