Topic: 2 sites, 2 e-smith servers, 2 DHCPs with dial-up backup??

[matt]

Hi Smitties.

I have been useing e-smith very sucessfull for about a year now, and have also upgraded to ADSL (with no help from bigpoo).  The server is used as a gateway, SMTP server (users get their own mail POP3 direct via the gateway), DHCP and the e-smith machine also has a phpBB forum running on it.  Nothing could be easier.

I recently split the office into 2 locations and they are connected by a 11MB radio link over about 1 Km and works like a champ.  Now things get sticky...  When it rains I loose the link (got a tree in the way).  So the PCs at the remote office have no mail and browsing blah blah blah.  My present way around this is to a have laptop sitting at the remote office and manually do a DUN to a ISP and then run around to all the PCs and change the account settings to the proxy via the laptop.  This also leaves me to have the remote PCs not useing DHCP.

What I would like to do is have a setup that has 2 e-smiths where the remote one would control its own DHCP (subnet??) and hand off the mail etc to the local one when the link is OK but when the link dies to then either start a RAS connection to the local site or a DUN to a local ISP just to get them emails out!  And when the link recovers to go back to the original setup.

Now I've seen reference to having 2 DHCPs here (must do some more reading), but I'd be buggered if I can figure a way or know where  to start to make the remote e-smith know if the link is up or down.

Please can anyone help?

Thanks.

Matt
www.intellect-cs.com

[Graeme Fleming]

G'Day Matt

In looking at your post a certain 'stream of dribble' occured

DHCP wise just split the IP range between the two servers so that either can respond to a valid request - NO ADDRESS OVERLAP!.  Don't forget to leave a block of addresses at each location for static assignment as required.

The link between your servers is essentially controlled via the routing table so perhaps you could run a cron job to test the link by pinging your private IP's on the other end.  If the link is down then rewrite the routing table so the PPP adaptor is the gateway - hey presto any inquiry should trigger a dialup (assuming it is properly defined) - I don't know if any other changes may be neccessary such as updating the DNS pointers, etc.

The same process could be used to take the PPP link down, but in reverse.

Feel free to discard all the above if my brain is failing me

Ciao from Perth

[matt]

Interesting..  Thanks for the answer.  Now be gentle I am a hardware type who has been thursted into this new world.  I'll go away and learn about "cron", but from what I understand about DHCP won't things get mixed up if I have 2 machines issuing leases?  Even if the ranges are very different?  If a machine asked for a lease and 2 machines answer does it only except the 1st one it heard?  And is this 2nd server put in as a lower gateway in the windoze boxes?

Also with the 2nd e-smith server I can't work out how to set it up!!  When the RF link is up, it is acting only as a server but when it discovers that the link is down, and starts a PPP DUN, it now becomes a gateway/server until it finds that the link is back again......

Many questions lots to learn.

Thanks.

Matt

[Scott]

matt wrote:
>
> Interesting..  Thanks for the answer.  Now be gentle I am a
> hardware type who has been thursted into this new world.
> I'll go away and learn about "cron", but from what I
> understand about DHCP won't things get mixed up if I have 2
> machines issuing leases?  Even if the ranges are very
> different?  If a machine asked for a lease and 2 machines
> answer does it only except the 1st one it heard?  And is this
> 2nd server put in as a lower gateway in the windoze boxes?
>
> Also with the 2nd e-smith server I can't work out how to set
> it up!!  When the RF link is up, it is acting only as a
> server but when it discovers that the link is down, and
> starts a PPP DUN, it now becomes a gateway/server until it
> finds that the link is back again......
>
> Many questions lots to learn.
>
> Thanks.
>
> Matt

Matt

I would set the second server up as a server gateway
that recieves a dhcp lease. In this way, weather the
server gets it's ip from your main server or from the
dialup connection it doesn't change it's settings.

Another possiblilty would be to simply move the
broadcast and reception antenae' to a different
location in the hopes of losing the tree interverence.
Possibly you could set up a repeater in the tree or
there abouts to shorten the distance, strengthen
the signal and eliminate the trees interference.

And if nothing else, cut the tree down. Did I
just say that? (M.E.L.)

Scott