ELTEX ESR-21 - Static NAT Configuration; Configuration Algorithm; Static NAT Configuration Example

ESR series service routers.ESR-Series. User manual
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Second step is to create SNAT rule set. In the set attributes, specify that the rules are applying only to packets
transferred to public network through te1/0/1 port. Rules include a check which ensures that data source
address belongs to 'LOCAL_NET' pool:
esr(config-snat)# ruleset SNAT
esr(config-snat-ruleset)# to interface te1/0/1
esr(config-snat-ruleset)# rule 1
esr(config-snat-rule)# match source-address LOCAL_NET
esr(config-snat-rule)# action source-nat pool TRANSLATE_ADDRESS
esr(config-snat-rule)# enable
esr(config-snat-rule)# exit
esr(config-snat-ruleset)# exit
In order the router could response to the ARP requests for addresses from the public pool, launch ARP Proxy
service. ARP Proxy service is configured on the interface that IP address from 'PUBLIC_POOL' public network
address profile subnet belongs to:
esr(config)# interface tengigabitethernet 1/0/1
esr(config-if-te)# ip nat proxy-arp PUBLIC_POOL
To enable public network access for LAN devices, they should be configured for routing – 21.12.2.1 should be
defined as a gateway address.
On the router, you should create the route for public network. Specify this route as a default using the following
command:
esr(config)# ip route 0.0.0.0/0 200.10.0.254
esr(config)# exit
16.4 Static NAT configuration
Static NAT — static NAT sets a unique match between two addresses. In other words, when passing through
the router the address is changed to another strictly specified one, one-to-one. The record about this
translation is kept indefinitely until NAT reconfiguration is carried out on the router.
16.4.1 Configuration algorithm
Static NAT configuration is carried out by Source NAT means, the configuration algorithm is described in
Section Source NAT configuration, configuration algorithm of the manual.
16.4.2 Static NAT configuration example
Objective:
Configure two-way and continuous translation from LAN for the addresses range of 21.12.2.100-21.12.2.150
to the public network 200.10.0.0/24. Public network address range for translation use –
200.10.0.100-200.10.0.150.