diff options
Diffstat (limited to 'relay')
| -rw-r--r-- | relay/dhcrelay.cat8 | 300 |
1 files changed, 150 insertions, 150 deletions
diff --git a/relay/dhcrelay.cat8 b/relay/dhcrelay.cat8 index 7dea2a27..4254a341 100644 --- a/relay/dhcrelay.cat8 +++ b/relay/dhcrelay.cat8 @@ -1,218 +1,214 @@ -dhcrelay(8) dhcrelay(8) +Maintenance Procedures dhcrelay(8) -NNAAMMEE - dhcrelay - Dynamic Host Configuration Protocol Relay Agent - -SSYYNNOOPPSSIISS - ddhhccrreellaayy [ --pp _p_o_r_t ] [ --dd ] [ --qq ] [ --ii _i_f_0 [ ...... --ii _i_f_N - ] ] [ --aa ] [ --AA _l_e_n_g_t_h ] [ --DD ] [ --mm _a_p_p_e_n_d | _r_e_p_l_a_c_e | - _f_o_r_w_a_r_d | _d_i_s_c_a_r_d ] _s_e_r_v_e_r_0 [ _._._._s_e_r_v_e_r_N ] - -DDEESSCCRRIIPPTTIIOONN - The Internet Software Consortium DHCP Relay Agent, dhcre - lay, provides a means for relaying DHCP and BOOTP requests - from a subnet to which no DHCP server is directly to one - or more DHCP servers on other subnets. - -OOPPEERRAATTIIOONN - The DHCP Relay Agent listens for DHCP and BOOTP queries - and responses. When a query is received from a client, - dhcrelay forwards it to the list of DHCP servers specified - on the command line. When a reply is received from a - server, it is broadcast or unicast (according to the relay - agent's ability or the client's request) on the network - from which the original request came. -CCOOMMMMAANNDD LLIINNEE - The names of the network interfaces that dhcrelay should - attempt to configure may be specified on the command line - using the --ii option. If no interface names are specified - on the command line dhcrelay will identify all network - interfaces, elimininating non-broadcast interfaces if pos - sible, and attempt to configure each interface. +NNNNAAAAMMMMEEEE + dhcrelay - Dynamic Host Configuration Protocol Relay Agent - If a relay agent is running on a system that is connected - to one or more networks on which no DHCP servers are pre - sent, and is also connected to one or more networks on - which DHCP servers _a_r_e connected, it is may not be helpful - for the relay agent to relay requests from those networks - on which a DHCP server already exists. To avoid such a - situation, the interfaces on which the relay agent should - listen should be specified with the --ii flag. +SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS + ddddhhhhccccrrrreeeellllaaaayyyy [ ----pppp _p_o_r_t ] [ ----dddd ] [ ----qqqq ] [ ----iiii _i_f_0 [ ............ ----iiii _i_f_N ] ] + [ ----aaaa ] [ ----AAAA _l_e_n_g_t_h ] [ ----DDDD ] [ ----mmmm _a_p_p_e_n_d | _r_e_p_l_a_c_e | _f_o_r_w_a_r_d + | _d_i_s_c_a_r_d ] _s_e_r_v_e_r_0 [ ..._s_e_r_v_e_r_N ] - Note that in some cases it _i_s helpful for the relay agent - to forward requests from networks on which a DHCP server - is running to other DHCP servers. This would be the case - if two DHCP servers on different networks were being used - to provide backup service for each other's networks. +DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN + The Internet Software Consortium DHCP Relay Agent, dhcrelay, + provides a means for relaying DHCP and BOOTP requests from a + subnet to which no DHCP server is directly to one or more + DHCP servers on other subnets. - If dhcrelay should listen and transmit on a port other - than the standard (port 67), the --pp flag may used. It - should be followed by the udp port number that dhcrelay - should use. This is mostly useful for debugging purposes. +OOOOPPPPEEEERRRRAAAATTTTIIIIOOOONNNN + The DHCP Relay Agent listens for DHCP and BOOTP queries and + responses. When a query is received from a client, dhcrelay + forwards it to the list of DHCP servers specified on the + command line. When a reply is received from a server, it is + broadcast or unicast (according to the relay agent's ability + or the client's request) on the network from which the ori- + ginal request came. - Dhcrelay will normally run in the foreground until it has - configured an interface, and then will revert to running - in the background. To run force dhcrelay to always run as +CCCCOOOOMMMMMMMMAAAANNNNDDDD LLLLIIIINNNNEEEE + The names of the network interfaces that dhcrelay should + attempt to configure may be specified on the command line + using the ----iiii option. If no interface names are specified on + the command line dhcrelay will identify all network inter- + faces, elimininating non-broadcast interfaces if possible, + and attempt to configure each interface. + If a relay agent is running on a system that is connected to + one or more networks on which no DHCP servers are present, + and is also connected to one or more networks on which DHCP + servers _a_r_e connected, it is may not be helpful for the + relay agent to relay requests from those networks on which a + DHCP server already exists. To avoid such a situation, the + interfaces on which the relay agent should listen should be + specified with the ----iiii flag. + Note that in some cases it _i_s helpful for the relay agent to + forward requests from networks on which a DHCP server is + running to other DHCP servers. This would be the case if + two DHCP servers on different networks were being used to + provide backup service for each other's networks. - 1 + If dhcrelay should listen and transmit on a port other than + the standard (port 67), the ----pppp flag may used. It should be + followed by the udp port number that dhcrelay should use. + This is mostly useful for debugging purposes. -dhcrelay(8) dhcrelay(8) +SunOS 5.6 Last change: 1 - a foreground process, the --dd flag should be specified. - This is useful when running dhcrelay under a debugger, or - when running it out of inittab on System V systems. - Dhcrelay will normally print its network configuration on - startup. This can be annoying in a system startup script - - to disable this behaviour, specify the --qq flag. -RREELLAAYY AAGGEENNTT IINNFFOORRMMAATTIIOONN OOPPTTIIOONNSS - If the --aa flag is set the relay agent will append an agent - option field to each request before forwarding it to the - server. Agent option fields in responses sent from - servers to clients will be stripped before forwarding such - responses back to the client. - The agent option field will contain two agent options: the - Circuit ID suboption and the Agent ID suboption. Cur - rently, the Circuit ID will be the printable name of the - interface on which the client request was received. The - Agent ID will be the value that the relay agent stores in - the DHCP packet's giaddr field. The client supports - inclusion of a Remote ID suboption as well, but this is - not used by default. - _N_o_t_e_: The Agent ID suboption is not defined in the current - Relay Agent Information Option draft (draft-ietf-dhc- - agent-options-03.txt), but has been proposed for inclusion - in the next draft. +Maintenance Procedures dhcrelay(8) - Relay Agent options are added to a DHCP packet without the - knowledge of the DHCP client. The client may have filled - the DHCP packet option buffer completely, in which case - there theoretically isn't any space to add Agent options. - However, the DHCP server may be able to handle a much - larger packet than most DHCP clients would send. The - current Agent Options draft requires that the relay agent - use a maximum packet size of 576 bytes. - It is recommended that with the Internet Software Consor - tium DHCP server, the maximum packet size be set to about - 1400, allowing plenty of extra space in which the relay - agent can put the agent option field, while still fitting - into the Ethernet MTU size. This can be done by specify - ing the --AA flag, followed by the desired maximum packet - size (e.g., 1400). - Note that this is reasonably safe to do even if the MTU - between the server and the client is less than 1500, as - long as the hosts on which the server and client are run - ning support IP fragmentation (and they should). With - some knowledge as to how large the agent options might get - in a particular configuration, this parameter can be tuned - as finely as necessary. + Dhcrelay will normally run in the foreground until it has + configured an interface, and then will revert to running in + the background. To run force dhcrelay to always run as a + foreground process, the ----dddd flag should be specified. This + is useful when running dhcrelay under a debugger, or when + running it out of inittab on System V systems. + Dhcrelay will normally print its network configuration on + startup. This can be annoying in a system startup script - + to disable this behaviour, specify the ----qqqq flag. +RRRREEEELLLLAAAAYYYY AAAAGGGGEEEENNNNTTTT IIIINNNNFFFFOOOORRRRMMMMAAAATTTTIIIIOOOONNNN OOOOPPPPTTTTIIIIOOOONNNNSSSS + If the ----aaaa flag is set the relay agent will append an agent + option field to each request before forwarding it to the + server. Agent option fields in responses sent from servers + to clients will be stripped before forwarding such responses + back to the client. + The agent option field will contain two agent options: the + Circuit ID suboption and the Agent ID suboption. Currently, + the Circuit ID will be the printable name of the interface + on which the client request was received. The Agent ID + will be the value that the relay agent stores in the DHCP + packet's giaddr field. The client supports inclusion of a + Remote ID suboption as well, but this is not used by + default. - 2 + _N_o_t_e: The Agent ID suboption is not defined in the current + Relay Agent Information Option draft (draft-ietf-dhc-agent- + options-03.txt), but has been proposed for inclusion in the + next draft. + Relay Agent options are added to a DHCP packet without the + knowledge of the DHCP client. The client may have filled + the DHCP packet option buffer completely, in which case + there theoretically isn't any space to add Agent options. + However, the DHCP server may be able to handle a much larger + packet than most DHCP clients would send. The current + Agent Options draft requires that the relay agent use a max- + imum packet size of 576 bytes. + It is recommended that with the Internet Software Consortium + DHCP server, the maximum packet size be set to about 1400, + allowing plenty of extra space in which the relay agent can + put the agent option field, while still fitting into the + Ethernet MTU size. This can be done by specifying the ----AAAA + flag, followed by the desired maximum packet size (e.g., + 1400). + Note that this is reasonably safe to do even if the MTU + between the server and the client is less than 1500, as long + as the hosts on which the server and client are running -dhcrelay(8) dhcrelay(8) +SunOS 5.6 Last change: 2 - It is possible for a relay agent to receive a packet which - already contains an agent option field. If this packet - does not have a giaddr set, the standard requires that the - packet be discarded. - If giaddr is set, the server may handle the situation in - one of four ways: it may _a_p_p_e_n_d its own set of relay - options to the packet, leaving the supplied option field - intact. It may _r_e_p_l_a_c_e the existing agent option field. - It may _f_o_r_w_a_r_d the packet unchanged. Or, it may _d_i_s_c_a_r_d - it. - Which of these behaviours is followed by the Internet - Software Consortium DHCP Relay Agent may be configured - with the --mm flag, followed by one of the four keywords - specified in _i_t_a_l_i_c_s above. - When the relay agent receives a reply from a server that - it's supposed to forward to a client, and Relay Agent - Information option processing is enabled, the relay agent - scans the packet for Relay Agent Information options and - removes them. As it's scanning, if it finds a Relay - Agent Information option field containing an Agent ID sub - option that matches one of its IP addresses, that option - is recognized as its own. If no such option is found, - the relay agent can either drop the packet, or relay it - anyway. If the --DD option is specified, all packets that - don't contain a match will be dropped. -SSPPEECCIIFFYYIINNGG DDHHCCPP SSEERRVVEERRSS - The name or IP address of at least one DHCP server to - which DHCP and BOOTP requests should be relayed must be - specified on the command line. -SSEEEE AALLSSOO - dhclient(8), dhcpd(8), RFC2132, RFC2131, draft-ietf-dhc- - agent-options-03.txt. +Maintenance Procedures dhcrelay(8) -BBUUGGSS - It should be possible for the user to define the Circuit - ID and Remote ID values on a per-interface basis. - The relay agent should not relay packets received on a - physical network to DHCP servers on the same physical net - work - if they do, the server will receive duplicate pack - ets. In order to fix this, however, the relay agent - needs to be able to learn about the network topology, - which requires that it have a configuration file. -AAUUTTHHOORR - ddhhccrreellaayy((88)) has been written for the Internet Software - Consortium by Ted Lemon <mellon@fugue.com> in cooperation - with Vixie Enterprises. To learn more about the Internet - Software Consortium, see hhttttpp::////wwwwww..vviixx..ccoomm//iisscc.. To learn + support IP fragmentation (and they should). With some + knowledge as to how large the agent options might get in a + particular configuration, this parameter can be tuned as + finely as necessary. + It is possible for a relay agent to receive a packet which + already contains an agent option field. If this packet does + not have a giaddr set, the standard requires that the packet + be discarded. + If giaddr is set, the server may handle the situation in one + of four ways: it may _a_p_p_e_n_d its own set of relay options to + the packet, leaving the supplied option field intact. It + may _r_e_p_l_a_c_e the existing agent option field. It may _f_o_r_w_a_r_d + the packet unchanged. Or, it may _d_i_s_c_a_r_d it. - 3 + Which of these behaviours is followed by the Internet + Software Consortium DHCP Relay Agent may be configured with + the ----mmmm flag, followed by one of the four keywords specified + in _i_t_a_l_i_c_s above. + When the relay agent receives a reply from a server that + it's supposed to forward to a client, and Relay Agent Infor- + mation option processing is enabled, the relay agent scans + the packet for Relay Agent Information options and removes + them. As it's scanning, if it finds a Relay Agent Informa- + tion option field containing an Agent ID suboption that + matches one of its IP addresses, that option is recognized + as its own. If no such option is found, the relay agent + can either drop the packet, or relay it anyway. If the ----DDDD + option is specified, all packets that don't contain a match + will be dropped. +SSSSPPPPEEEECCCCIIIIFFFFYYYYIIIINNNNGGGG DDDDHHHHCCCCPPPP SSSSEEEERRRRVVVVEEEERRRRSSSS + The name or IP address of at least one DHCP server to which + DHCP and BOOTP requests should be relayed must be specified + on the command line. +SSSSEEEEEEEE AAAALLLLSSSSOOOO + dhclient(8), dhcpd(8), RFC2132, RFC2131, draft-ietf-dhc- + agent-options-03.txt. +BBBBUUUUGGGGSSSS + It should be possible for the user to define the Circuit ID + and Remote ID values on a per-interface basis. -dhcrelay(8) dhcrelay(8) + The relay agent should not relay packets received on a phy- + sical network to DHCP servers on the same physical network - + if they do, the server will receive duplicate packets. In + order to fix this, however, the relay agent needs to be able + to learn about the network topology, which requires that it + have a configuration file. - more about Vixie Enterprises, see hhttttpp::////wwwwww..vviixx..ccoomm.. +SunOS 5.6 Last change: 3 +Maintenance Procedures dhcrelay(8) +AAAAUUUUTTTTHHHHOOOORRRR + ddddhhhhccccrrrreeeellllaaaayyyy((((8888)))) has been written for the Internet Software Con- + sortium by Ted Lemon <mellon@fugue.com> in cooperation with + Vixie Enterprises. To learn more about the Internet + Software Consortium, see hhhhttttttttpppp::::////////wwwwwwwwwwww....vvvviiiixxxx....ccccoooommmm////iiiisssscccc.... To learn + more about Vixie Enterprises, see hhhhttttttttpppp::::////////wwwwwwwwwwww....vvvviiiixxxx....ccccoooommmm.... @@ -259,6 +255,10 @@ dhcrelay(8) dhcrelay(8) - 4 + + + +SunOS 5.6 Last change: 4 + |