Alcatel-Lucent 7750 SR OS Service Manual page 747

server
Syntax server server1 [server2...(up to 8 max)]
Context config>service>ies>if>dhcp
config>service>ies>sub-if>grp-if>dhcp
Description
This command specifies a list of servers where requests will be forwarded. The list of servers can be
entered as either IP addresses or fully qualified domain names. There must be at least one server
specified for DHCP relay to work. If there are multiple servers then the request is forwarded to all of
the servers in the list.
There can be a maximum of 8 DHCP servers configured.
Default
no server
Parameters
server — Specify the DHCP server IP address.
trusted
Syntax [no] trusted
Context config>service>ies>if>dhcp
config>service>ies>sub-if>grp-if>dhcp
Description
According to RFC 3046, DHCP Relay Agent Information Option, a DHCP request where the giaddr
is 0.0.0.0 and which contains a Option 82 field in the packet, should be discarded, unless it arrives on
a "trusted" circuit. If trusted mode is enabled on an IP interface, the Relay Agent (the router) will
modify the request's giaddr to be equal to the ingress interface and forward the request.
Note that this behavior only applies when the action in the Relay Agent Information Option is "keep".
In the case where the Option 82 field is being replaced by the Relay Agent (action = "replace"), the
original Option 82 information is lost anyway, and there is thus no reason for enabling the trusted
option.
The no form of this command returns the system to the default.
Default
not enabled
gi-address
Syntax gi-address ip-address [src-ip-addr]
no gi-address
Context config>service>ies>if>dhcp
config>service>ies>sub-if>grp-if>dhcp
Description
This command configures the gateway interface address for the DHCP relay. A subscriber interface
can include multiple group interfaces with multiple SAPs. The GI address is needed, when the router
functions as a DHCP relay, to distinguish between the different subscriber interfaces and potentially
between the group interfaces defined.
By default, the GI address used in the relayed DHCP packet is the primary IP address of a normal IES
interface. Specifying the GI address allows the user to choose a secondary address. For group
7750 SR OS Services Guide
Internet Enhanced Services
Page 747