ESR Series Routers Operation Manual
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7.6
Destination NAT configuration
Destination NAT (DNAT) function includes destination IP address translation for packets transferred
through the network gateway.
DNAT is used for redirection of traffic, coming to a specific 'virtual' address in a public network, to a
'real' server in LAN located behind the network gateway. This function may be used for establishing a
public access to servers located within the private network without any public network address.
Objective
: Establish access from the public network, that belongs to the 'UNTRUST' zone, to LAN
server in 'TRUST' zone. Server address in LAN
—
10.1.1.100. Server should be accessible from outside the
network
—
address 1.2.3.4, access port 80.
Fig. 7.4
—
Network structure
Solution
:
Create 'UNTRUST' and 'TRUST' security zones. Define the inherence of the network interfaces being
used to zones. Assign IP addresses to interfaces simultaneously.
esr#
configure
esr(config)#
security zone UNTRUST
esr(config-zone)#
exit
esr(config)#
security zone TRUST
esr(config-zone)#
exit
esr(config)#
interface gigabitethernet 1/0/1
esr(config-if-gi)#
security-zone TRUST
esr(config-if-gi)#
ip address 10.1.1.1/25
esr(config-if-gi)#
exit
esr(config)#
interface tengigabitethernet 1/0/1
esr(config-if-te)#
ip address 1.2.3.4/29
esr(config-if-te)#
security-zone UNTRUST
esr(config-if-te)#
exit
Create IP address and port profiles required for configuration of the Firewall and DNAT rules.
NET_UPLINK
—
public network address profile
SERVER_IP
—
local area network address profile
SRV_HTTP
—
port profile
esr(config)#
object-group network NET_UPLINK
esr(config-object-group-network)#
ip address 1.2.3.4
esr(config-object-group-network)#
exit
esr(config)#
object-group service SRV_HTTP
esr(config-object-group-network)#
port 80
esr(config-object-group-network)#
exit
esr(config)#
object-group network SERVER_IP
esr(config-object-group-network)#
ip address 10.1.1.100
esr(config-object-group-network)#
exit
