[NCSA-discuss] wrt54gs and openwrt, rfc1918/dhcp question

[Brian Wilson]

On 1/19/06, Rick DeNatale <rick.denatale at gmail.com> wrote:
> On 1/19/06, Steven Champeon <schampeo at hesketh.com> wrote:
> >
> > Hello, group.
> >
> > I've got a question for anyone who's used the openwrt package to replace
> > the built-in functionality of a Linksys WRT54G*. Or, for anyone using
> > the WRT54GS inside a larger network (as opposed to as a home cable/dsl
> > access point).
> >
> > At the moment, our internal network is relatively simple: Linux firewall
> > masquerading traffic using iptables from our rfc1918 (192.168.1.0/24)
> > internal net to the outside. Works great.
> >
> > I've got two Apple Airport base stations (one graphite, one snow) doing
> > DHCP and handing out 192.168.1.x addresses, and shuffling traffic from
> > the wifi world to the hardwire world. Again, no problems, works great.
> >
> > Problem is, I've been asked to provide 802.11g support, and the existing
> > Apples only do 802.11b. Rather than pay $250 or so for a new BS Extreme,
> > I sent the CFO out to best buy and she got a WRT54GS and PC cards to
> > match (oh, well - close enough; I asked her to get WRT54Gs :).
> >
> > Seems, however, that the s/w that comes with the WRT54GS expects to hand
> > out 192.168.1.x addresses - and there's no way to change it. Also, it
> > doesn't seem to want me to treat its IP as anything but 192.168.1.1.
> > Well, I've already got one of those, thanks. And I'd like to be able to
> > say "hey, WRT, be 192.,168.1.129, and hand out IPs from 130 to 140" or
> > some such, and have it route traffic over to 192.168.1.1, my Linux
> > firewall, and on the internal network.
>
> Well my WRT54G with stock Linksys firmware lets me change it's LOCAL
> IP address.  I'm running it as 192.168.0.12.  I'm not using the WAN
> port at all, since it's inside my LAN, and I'm using it as an access
> point rather than a router.
>
> Right below that is the DHCP server settings.  I've got DHCP turned
> off since I use another server on the lan for DHCP, but if I enabled
> DHCP, it's offering 192.168.0.x as the starting client address and has
> a count for maximum client count. It's keeping the client addresses
> inside the subnet mask, which seems to make sense. <G>
> >
> > So, I've been looking at maybe throwing openwrt on it, in hopes that it
> > will allow it to behave like the Apple Airports do, and let me assign an
> > IP of my choosing and tell it to hand out DHCP addresses in 192.168.1.y-z
> > as well, without overlapping the ranges I've already assigned to the
> > DHCP server on the Airports.
> >
> > Anyone play with this, have any advice, warnings, recipes, etc.?
> >
> > It's not really that complex a network setup. But it seems to be too much
> > to ask for from the WRT54GS, which is obviously targeted at your typical
> > home audience.
> >
> > So, do I take a chance at turning it into a brick, take it back and
> > trade it for a different Linksys model, or is there a trick to making
> > it act like something other than a dumbed-down consumer grade AP?
>
> It might not be an option if you recently bought it. What's the
> firmware version?  If its >= Version 5 you've got one of the new
> slimmed down boxes which are running VxWorks instead of Linux and
> don't have enough RAM to support OpenWrt.  There's a special "classic"
> WRT54GL" which was put into the product line after they switched, but
> I don't believe that brick and mortar retailers are stocking it.
>
> http://www.linuxdevices.com/news/NS4729641740.html
>

Looks like his CTO purchased GS's and not G's.  Only the new G's are
VxWorks.   The most current GS's (v4.0) should run the 3rd party
firmwares (dd-wrt, openwrt, sveasoft) with no issues.  Make sure you
check the documentation specific to each vendor to be sure.

Brian