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60 SunOS 5.11 Last change: 15 May 2008 1
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67 System Administration Commands dhcpagent(1M)
68
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71 dhcpagent monitors link up/down events and will validate
72 any non-permanent leases with the DHCP server when the
73 downed link is brought back up.
74
75
76 For IPv4, if the configured interface is found to be
77 unplumbed, marked down, or to have a different IP address,
78 subnet mask, or broadcast address from those obtained from
79 DHCP, the interface is abandoned by DHCP control.
80
81
82 For IPv6, dhcpagent automatically plumbs and unplumbs logi-
83 cal interfaces as necessary for the IPv6 addresses supplied
84 by the server. The IPv6 prefix length (netmask) is not set
85 by the DHCPv6 protocol, but is instead set by in.ndpd(1M)
86 using prefix information obtained by Router Advertisements.
87 If any of the logical interfaces created by dhcpagent is
88 unplumbed, marked down, or configured with a different IP
89 address, it will be abandoned by DHCP control. If the link-
90 local interface is unplumbed, then all addresses configured
91 by DHCP on that physical interface will be removed.
92
93
94 In addition to DHCP, dhcpagent also supports BOOTP (IPv4
95 only). See RFC 951, Bootstrap Protocol. Configuration param-
96 eters obtained from a BOOTP server are treated identically
97 to those received from a DHCP server, except that the IP
98 address received from a BOOTP server always has an infinite
99 lease.
100
101
102 DHCP also acts as a mechanism to configure other information
103 needed by the client, for example, the domain name and
104 addresses of routers. Aside from the IP address, and for
105 IPv4 alone, the netmask, broadcast address, and default
106 router, the agent does not directly configure the worksta-
107 tion, but instead acts as a database which may be interro-
108 gated by other programs, and in particular by dhcpinfo(1).
109
110
111 On clients with a single interface, this is quite straight-
724
725
726
727 System Administration Commands dhcpagent(1M)
728
729
730
731 Droms, R., Dynamic Host Configuration Protocol, RFC 2131,
732 Network Working Group, March 1997.
733
734
735 Lemon, T. and B. Sommerfeld. RFC 4361, Node-specific Client
736 Identifiers for Dynamic Host Configuration Protocol Version
737 Four (DHCPv4). Nominum and Sun Microsystems. February 2006.
738
739
740 Droms, R. RFC 3315, Dynamic Host Configuration Protocol for
741 IPv6 (DHCPv6). Cisco Systems. July 2003.
742
743 NOTES
744 The dhcpagent daemon can be used on IPv4 logical interfaces,
745 just as with physical interfaces. When used on a logical
746 interface, the daemon automatically constructs a Client ID
747 value based on the DUID and IAID values, according to RFC
748 4361. The /etc/default/dhcpclient CLIENT_ID value, if any,
749 overrides this automatic identifier.
750
751
752 As with physical IPv4 interfaces, the /etc/hostname.hme0:1
753 and /etc/dhcp.hme0:1 files must also be created in order for
754 hme0:1 to be automatically plumbed and configured at boot.
755 In addition, unlike physical IPv4 interfaces, dhcpagent does
756 not add or remove default routes associated with logical
757 interfaces.
758
759
760 With DHCPv6, the link-local interface must be configured
761 using /etc/hostname6.hme0 in order for DHCPv6 to run on hme0
762 at boot time. The logical interfaces for each address are
763 plumbed by dhcpagent automatically.
764
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60 SunOS 5.11 Last change: 15 May 2008 1
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67 System Administration Commands dhcpagent(1M)
68
69
70
71 dhcpagent monitors link up/down events and will validate
72 any non-permanent leases with the DHCP server when the
73 downed link is brought back up.
74
75
76 For IPv4, if the configured interface is found to be
77 unplumbed, or to have a different IP address, subnet mask,
78 or broadcast address from those obtained from DHCP, the
79 interface is abandoned from DHCP control.
80
81
82 For IPv6, dhcpagent automatically plumbs and unplumbs
83 logical interfaces as necessary for the IPv6 addresses
84 supplied by the server. The IPv6 prefix length (netmask) is
85 not set by the DHCPv6 protocol, but is instead set by
86 *in.ndpd(1M)* using prefix information obtained by Router
87 Advertisements. If any of the logical interfaces created by
88 dhcpagent is unplumbed, or configured with a different IP
89 address, it will be abandoned from DHCP control. If the
90 link-local interface is unplumbed, then all addresses
91 configured by DHCP on that physical interface will be
92 removed.
93
94
95 In addition to DHCP, dhcpagent also supports BOOTP (IPv4
96 only). See RFC 951, Bootstrap Protocol. Configuration param-
97 eters obtained from a BOOTP server are treated identically
98 to those received from a DHCP server, except that the IP
99 address received from a BOOTP server always has an infinite
100 lease.
101
102
103 DHCP also acts as a mechanism to configure other information
104 needed by the client, for example, the domain name and
105 addresses of routers. Aside from the IP address, and for
106 IPv4 alone, the netmask, broadcast address, and default
107 router, the agent does not directly configure the worksta-
108 tion, but instead acts as a database which may be interro-
109 gated by other programs, and in particular by dhcpinfo(1).
110
111
112 On clients with a single interface, this is quite straight-
725
726
727
728 System Administration Commands dhcpagent(1M)
729
730
731
732 Droms, R., Dynamic Host Configuration Protocol, RFC 2131,
733 Network Working Group, March 1997.
734
735
736 Lemon, T. and B. Sommerfeld. RFC 4361, Node-specific Client
737 Identifiers for Dynamic Host Configuration Protocol Version
738 Four (DHCPv4). Nominum and Sun Microsystems. February 2006.
739
740
741 Droms, R. RFC 3315, Dynamic Host Configuration Protocol for
742 IPv6 (DHCPv6). Cisco Systems. July 2003.
743
744 NOTES
745 DHCP can be performed on IPv4 logical interfaces just as
746 with physical interfaces. When used on a logical interface,
747 the daemon automatically constructs a Client ID value based
748 on the DUID and IAID values, according to RFC 4361. The
749 */etc/default/dhcpclient* *CLIENT_ID* value, if any,
750 overrides this automatic identifier.
751
752
753 As with physical IPv4 interfaces, the /etc/hostname.hme0:1
754 and /etc/dhcp.hme0:1 files must also be created in order for
755 hme0:1 to be automatically plumbed and configured at boot.
756 In addition, unlike physical IPv4 interfaces, dhcpagent does
757 not add or remove default routes associated with logical
758 interfaces.
759
760
761 DHCP can be performed on IPMP IP interfaces to acquire and
762 maintain IPMP data addresses. Because an IPMP IP interface
763 has no hardware address, the daemon automatically constructs
764 a Client ID using the same approach described above for IPv4
765 logical interfaces. In addition, the lack of a hardware
766 address means the daemon must set the "broadcast" flag in
767 all *DISCOVER* and *REQUEST* messages on IPMP IP interfaces.
768 Some DHCP servers may refuse such requests.
769
770
771 DHCP can be performed on IP interfaces that are part of an
772 IPMP group (to acquire and maintain test addresses). The
773 daemon will automatically set the *NOFAILOVER* and
774 *DEPRECATED* flags on each test address. Additionally, the
775 daemon will not add or remove default routes in this case.
776 Note that the actual DHCP packet exchange may be performed
777 over any active IP interface in the IPMP group. It is
778 strongly recommended that test addresses have infinite
779 leases. Otherwise, an extended network outage detectable
780 only by probes may cause test address leases to expire,
781 causing *in.mpathd(1M)* to revert to link-based failure
782 detection and trigger an erroneous repair.
783
784
785 With DHCPv6, the link-local interface must be configured
786 using /etc/hostname6.hme0 in order for DHCPv6 to run on hme0
787 at boot time. The logical interfaces for each address are
788 plumbed by dhcpagent automatically.
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