Network Router User Manual

Chapter 16: Network Address Translation Configuration Guide
222 SmartSwitch Router User Reference Manual
Managing Dynamic Bindings
As mentioned previously, dynamic address bindings expire only after a period of non-use
or when they are manually deleted. The default timeout for dynamic address bindings is
1440 minutes (24 hours). You can manually delete dynamic address bindings for a specific
address pool or delete all dynamic address bindings.
To set the timeout for dynamic address bindings, enter the following command in
Configure mode.
To flush dynamic address bindings, enter the following command in Enable mode.
NAT and DNS
NAT can translate an address that appears in a Domain Name System (DNS) response to a
name or inverse lookup. For example, if an outside host sends a name lookup to an inside
DNS server, the inside DNS server can respond with a local IP address, which NAT
translates to a global address.
You create NAT dynamic bindings for DNS by entering the following command in
Configure mode.
DNS packets that contain addresses that match the ACL specified by outside-local-acl-
pool are translated using local addresses allocated from inside-global-pool.
Set timeout for dynamic address
bindings.
nat set dynamic-binding-timeout <minutes>
|
disable
Flush all dynamic address
bindings.
nat flush-dynamic-binding all
Flush dynamic address bindings
based on local and global ACL
pools.
nat flush-dynamic-binding pool-specified
local-acl-pool
<local-acl> global-pool
<ip-addr/ip-addr-range/ip-addr-list/ip-addr-
mask>
Flush dynamic address bindings
based on binding type.
nat flush-dynamic-binding type-specified
dynamic|overloaded-dynamic
Flush dynamic address bindings
based on application.
nat flush-dynamic-binding owner-specified
dns|ftp-control|ftp-data
Enable NAT with dynamic
address binding for DNS
query/reply.
nat create dynamic local-acl-pool <outside-
local-acl>
global-pool <ip-addr/ip-addr-
range/ip-addr-list/ip-addr-mask>