On Sun, 17 Jan 1999, Joel A. Matz wrote:
> I have a situation where I need to access 2 dialup ppp servers. One is
> my default ISP for general internet traffic, while the other is work
> related and should only go up based on a certain class b address group.
Simplicity is a virtue. You should stick to just one provider if
possible. If cost is an issue you can do IP accounting to compare the
number of packets going to different destinations and split the cost
accordingly. If security is an issue you can arrange IP tunneling through
the ISP to a machine at work.
> Obviously both have different nameservers, but I can put most of
> the work related stuff in /etc/hosts.
In a typical setup, diald comes up on a name resolution request which
always goes to a nameserver. I don't know how you can arrange it so that
names on one subnet are resolved by one nameserver while names elsewhere
are resolved by another. I can see a number of alternatives, among which
are:
1) Keep all the DNS information for work on your local machine.
/etc/hosts is a quick, error-prone way of doing it. Better would be to
run named on your local machine and arrange periodic transfers of
information from the nameserver at work. In either case you will need to
run
echo 5 > /proc/sys/net/ipv4/ip_dynaddr
if your IP address is dynamically assigned by your ISP or the ppp server
at work.
2) Use only one set of nameservers, say at your ISP. Then if you
requested a name on your work net, the connection to the ISP would come up
to resolve the name, would go down shortly thereafter, and then the
connection to work would come up. You'll need the same magic echo line as
in 1). Kind of wacky, but there it is.
I believe that in either case your connections will be more prone to
timeouts while waiting for the connection to go up (in a typical setup
name resolution extends the time before a connection times out). You may
have to recompile your kernel to change some timeout values. I'm no
expert on that; I restart named in order to flush the cache when the
connection goes down so that my diald almost always brings the connection
up on a name resolution request.
> Can this be done? Do i need to instances of diald running? any
> examples?
If you really want to do it with the current version of diald, it can be
done by running two copies of diald. You'll need two different slip and
ppp devices supported by your kernel (maybe you'll have to compile them as
modules?). Just start up the diald's with different configuration files
specified on the command lines. Make sure you don't mix up the order in
which the diald's are started: you want to assign the slip/ppp devices
consistently to the same diald. (Perhaps there's a more sure-fire way of
doing that than just starting the diald's in the correct order.) Then
you'll just have to add a special net route to send packets through the
work diald to the work net; only the ISP diald should contain the
defaultroute directive.
If you want to access work machines while connected to the ISP you can add
routing commands to ip-up, I guess, but that would defeat the purpose of
the entire elaborate setup.
Ed
--
Ed Doolittle <mailto:[EMAIL PROTECTED]>
"Everything we do, we do for a reason." -- Peter O'Chiese
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