Router - TG582N - Mixed NAT: Difference between revisions

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[[Image:T582-small.png|link=:Category:~~Router_TG582N~~|Got to Main TG582N Page]]

[[Image:T582-small.png|link=:Category:Router TG582N|Got to Main TG582N Page]]

This is how to configure a Technicolor gateway with two subnets on its

local network such that one gets translated and the other ~~does~~

local network such that one subnet gets its addresses translated by NAT and the other

subnet does not get NATed. Or, looking at it differently, adding a subnet of (e.g.)

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~~not.~~ ~~This configuration~~ is not recommended, far better to use a real

RFC1918 addresses which will be NATed on a router with an existing routeable IP block setup.

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Mixed NAT is not recommended, far better to use a real

router made out of FireBrick, BSD or Linux that gives proper control of things

on an address level rather than on an interface.

on an address level rather than on an interface level.

Firstly, you need to put a public address on the Ethernet interface.

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this needs to be added for each of the public addresses that have been

assigned. Thankfully these days only small blocks are obtainable.

''[Actually according to an application note it is possible to specify address ranges, e.g.''

:nat mapadd intf=Internet type=nat outside_addr=192.0.2.[2-6] inside_addr=192.0.2.[2-6]

''but your author doesn't have enough routeable addresses to check that this works.]''

== Firewalling ==

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There is ~~still~~ a problem, however, if you want to allow unfettered

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~~access~~ ~~inbound to~~ ~~that~~ address -- it will get caught by the stateful

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There is a problem, however, if you want to allow unfettered access inbound

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to the routeable address(es) -- it will get caught by the stateful

firewall. Again there appears to be no way to selectively disable the

keeping of state, so it must be turned off globally:

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parameter to restrict the mapping to specified inside addresses,

so you could NAT some inside address blocks to one outside address, and

others to a different outside address.

others to a different outside address. And even add a ''foreign_addr''

parameter to only use this mapping for a range of destination addresses.

Note that when PPP IPCP comes up it automatically adds an entry like

:nat mapadd intf=Internet type=napt outside_addr=<my_ppp_addr> weight=50

to the end of the NAT map - see

:nat maplist expand=enabled

but any entries made by the user will take priority.

Note also that specifying the outside address means that the outside address

used will not be that of any PPP link in use by the router. So, for example, if you have

a fallback to a 3G USB modem setup and the fallback takes place then you will

perhaps be sending packets with a source address of one of your AAISP addresses

rather than an auto-assigned address from your 3G provider. If your 3G is

AAISP's Broadband Backup product you'll be OK though.

==Other pages regarding this router:==

==Other pages regarding this router==

<ncl style=bullet maxdepth=5 headings=bullet headstart=2 showcats=1 showarts=1 showfirst=1>Category:Router TG582N</ncl>

[[Category:Router TG582N]]

[[Category:Router TG582N|Mixed]]

[[Category:Router]]