Ruijie RG-S2900G-E Series, Configuration Manual

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Configuration Guide DHCP Relay Configuration
Command Function
Ruijie(config)# no IP helper-address
[ vrf word ]
A.B.C.D
Delete the globally configured IP address of
the DHCP server.
Ruijie(config-if)# no IP
helper-address [ vrf word ] A.B.C.D
Delete the IP address of the DHCP server
configured on the interface.
Configuring DHCP manage-vlan
Users will configure an address and a mask for each interface when they
configure the DHCP RELAY downlink interface. The DHCP server uses RELAY
to allocate addresses that share the same network segment with the RELAY
downlink interfaces connected to the client. But if the DHCP RELAY enables the
option82 function, the DHCP server will confirm the IP address type by the
option82 information when it allocates the addresses. So when we use option82
function, the configured address and mask on the interface are actually not
used during the address allocating process. But if the address and mask are not
configured, the packets cannot be sent to the DHCP RELAY application module
for processing since the address is not availabe on the interface. Particularly for
weak layer 3 device such as S29, users are more likely use it as layer 2 device.
So normally, users only configures a manage-vlan address, which is configured
on the designated SVI interface in a certain VLAN. Here we can designae all
source interfaces of the DHCP RELAY downlink interfaces as the manage-vlan,
and the packet can be successfully sent to the DHCP RELAY application
module and implement the DHCP managemeng function.
The above function is used in the condition of the DHCP RELAY option82
funciton enabled. There might be several VLAN interfaces as the DHCP RELAY
downlink interfaces. When this function is disabled, create a SVI for every
downlink VLAN interface and configure the IP address. When this function is
enabled, SVIs are not necessary for the downlink VLAN interfaces, and it only
requires to use this command to designate all uplink packet source interfaces at
the clients as manage VLAN interfaces. In this way, the configuration is
simplified and the addresses are saved.
In global configuration mode, follow the steps to configure the DHCP manage-valan.
Command Function
Ruijie(config)# ip dhcp relay
information manage-vlan vlanid
Enable the DHCP manage-vlan function
and designate the source interface as
vlan vlanid .
Ruijie(config)# no ip dhcp relay
information manage-vlan
Disable the DHCP manage-vlan
function.