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LTP-8X optical line terminal
65
In addition to DHCP option 82, DHCP Relay Agent has some more functions related to network security.
It provides protection from DoS attacks by setting a threshold for intensity of DHCP messages which are
received from ONT. Exceeding the threshold blocks DHCP requests. The blocking time can be configured.
It also protects from illegal DHCP servers by controlling the source IP address of DHCP responses.
Transmitted are only the DHCP responses which arrived from IP addresses of trusted DHCP servers.
17.1
DHCP Relay Agent Profiles Management
A set of profiles is used for DHCP Relay Agent configuration. All VLANs use profile 0 by default.
The configuration is flexible as it allows DHCP profiles to be assigned not only to a terminal on the
whole, but separately to each VLAN as well. To assign a profile, the following steps should be taken.
Step 1.
Assign the default profile for all VLANs with the help of the
gpon olt profile dhcpra
add dhcp-
ra-00
command.
LTP-8X# configure terminal
LTP-8X(config)# gpon olt profile dhcpra dhcp-ra-00
Step 2.
Create a new DHCP Relay Agent profile with the help of the
profile dhcp-ra
command, if
necessary.
Pass profile name as a parameter.
LTP-8X(config)# profile dhcp-ra dhcp-ra-01
LTP-8X(config-dhcp-ra)("dhcp-ra-01")# exit
Step 3.
Assign the newly created profile to the selected VLAN with the
gpon olt profile dhcpra dhcp-ra-
01
command
.
As a parameter, pass the VID which requires individual configuration.
LTP-8X(config)# gpon olt profile dhcpra dhcp-ra-01 1000
Step 4.
Check the changes by using the
show gpon olt configuration
command.
LTP-8X(config)# do show gpon olt configuration
Block duplicated mac: enabled
Ont block time: 5
Dhcpra shaper: 100
Profile pppoe-ia: pppoe-ia-00
OLT Profile PPPoE Intermediate Agent 0
Profile dhcp-ra: dhcp-ra-00
OLT Profile DHCP Relay Agent 0
Profile dhcp-ra per VLAN 1000 [0]:
Profile: dhcp-ra-01
OLT Profile DHCP Relay Agent 1
Step 5.
Apply the changes by using the
do commit
command.
LTP-8X(config)# do commit
To apply the changes, OLT should be reconfigured.