D-Link DSL-320T Ethernet ADSL2/2+ Modem and pfSense

  • Just ordered one of these cheap modems. It's an ADSL modem with Ethernet.  It is not a router.  I will give it a try with pfSense and report back here later.

    The older version (DSL-300) was reviewed on AdslGuide.org.uk.  Apparently, the modem takes at startup for web GUI setup.  But once the ADSL link comes up, the modem becomes transparent (no IP) and it serves you the ISP-assigned IP via DHCP.  So compared to a router, you're saving on IP addresses.

    Now for a basic routing question!  In my old setup, I use an ADSL router. This uses a /32 static IP on the ADSL port, with routing to my /29 static IP block on the Ethernet port.  In pfSense, I assign Virtual IPs for all usable IPs in the /29 block,  then I use the pfSense NAT to map specific IP/port combinations to specific public servers via different NICs, using different RFC1918 address ranges (192.168.x.*/24 with a different 'x' for each NIC).

    But, how do I change this setup over to use the ADSL modem?  Can I still use the Virtual IPs in the same way, or will it be a problem that the external ADSL WAN IP does not lie inside the same /29 block?  Will the /29 block still be routable from the ISP?


    • Martin.

  • I think that the only thing you need to change is the WAN gateway. Otherwise all else should be OK.

    Presumably your old setting had the adsl modem as the WAN gateway, now you need to find out what the gateway should be.

  • Well, as expected, it didn't really work.  I could surf the web, but my public network services weren't visible to the Internet.

    I was half-hoping that the D-Link box would be so stupid that it would just forward packets blindly between interfaces, but I guess it's just  a crippled router.  So without anywhere to set up multiple IPs or static routes, I guess it just doesn't know where to send traffic for my static IP range.

    The D-Link box runs Linux internally, so it may be possible to use a third-party firmware image to make it do something more sensible.  I'll try it out and post back here if I get anywhere with it.

    • Martin.

  • Some unofficial firmware is available from some cool people at http://www.routertech.org

    I got their firmware to flash onto the D-Link box to turn it into a working Linux router.  But it doesn't seem to keep the DSL line up for more than a minute or two at a time.  I guess you get what you pay for with routers!

    So - the DSL-320T is not a recommended product for connecting pfSense to ADSL.

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