Re: [Astlinux-users] Hairpin NAT

[Lonnie A. <li...@lo...>]

> On Apr 17, 2020, at 4:22 PM, Michael Knill <mic...@ip...> wrote:
> 
> Hi Group
>  
> I should know this but is it possible for Astlinux to do hairpin NAT e.g. they can do http://<external IP>:<external port> connecting to an internal host both internally and externally?
> If not then I assume the only way is to use DNS and resolve to the internal host address when internal.
>  
> Thanks

The "nat-loopback" plugin should do what you want.

=====================
# ------------------------------------------------------------------------------
#             -= Arno's iptables firewall - NAT Loopback plugin =-
# ------------------------------------------------------------------------------

# To actually enable this plugin make ENABLED=1:
# ------------------------------------------------------------------------------
ENABLED=0

# NAT Loopback for local nets using existing NAT_FORWARD_TCP and NAT_FORWARD_UDP
# rules.
# Note: The default external IPv4 address is obtained from the first
#       interface defined in the EXT_IF variable.
#
# Limit local nets by defining NAT_LOOPBACK_NET, a space separated list.
# Defaults to NAT_INTERNAL_NET if not defined.
#
# Example:
#   NAT_LOOPBACK_NET="192.168.1.0/24"
# (IPv4 Only)
# ------------------------------------------------------------------------------
NAT_LOOPBACK_NET=""

# When local servers are in another LAN they are unreachable (by default) unless
# FORWARD rules are created.  When NAT_LOOPBACK_FORWARD is set to "1" the
# FORWARD rules to the servers are created for all subnets in NAT_LOOPBACK_NET.
#
# Defaults to no added forwards if not set to "1"
# ------------------------------------------------------------------------------
NAT_LOOPBACK_FORWARD=0
=====================

Lonnie