[Scottish] ADSL router with no-nat configuration

Tam McLaughlin scottish at mailman.lug.org.uk
Fri Mar 21 10:12:01 2003

I am having problems setting up a solwise SAR110 adsl router with a no-nat 
configuration and wonder if anyone here has set up an adsl router with a 
similar config. I simply want to connect the router to our smoothwall and 
have been allocated an address range of 4 ip addresses. The problem seems to 
be with the default route not going through the ppp interface.

Our ISP said they cannot help, despite having tutorials for no-nat setups for 
two other types of modems but not this supplied one.

I was able to set up the router with the standard nat option ok, but according 
to the ISP, to set it up as no-nat, all I need to do is configure  eth-0 with 
appropriate ip address/mask from range supplied.

To test this, I have set up a laptop with the other useable ip address/mask 
and the laptop and router can talk to one another. 
The router gets authenticated and connected to the ISP network (As confirmed 
by support) and sets up some dynamic routes. 
I have tried configuring the router by leaving the ip address of the ppp 
interface blank, which automatically gets allocated the correct ip address on 
connection and also set the ip address manually on the ppp interface.

This is the routing table with a no-nat config where:

address range:
Destination           netmask           next hop            ifname  type             eth-0   indirect               lo-0    direct      eth-0   indirect  eth-0   indirect  eth-0   indirect      eth-0  direct           lo-o   direct

the routing table with the nat config is similar but the default route is via
ppp-0             ppp-0   indirect      ppp-0   direct

The configuration (web and CLI) does not allow me to specify the interface 
when adding or modifying routes. 
Support also gave me instructions on adding a BIMAP nat rule which does not
work either.

Any help would be appreciated.