[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Firewall to two networks



On 22 Aug 2002 at 12:01, Vince Mulhollon wrote:

> Here's the important part:
> Post your /sbin/route -n from the firewall itself.
> Also post your ifconfig from the firewall.

Dear Vince and others: I've had no response to posting those on the 
list but have slept on the problem and maybe understand more now.  

If anyone can find time to comment on these thoughts and my posting 
of the route and ifconfig information on the list last night, I'd 
hugely appreciate it as I'm still unconfident that I understand and 
the linux firewall HOWTO seems to say I should be able to ping to and 

from those cards.

Currently I can't ping out from the inward facing cards on the future 

firewall to a numeric address on the same hub.  Sleeping on it makes 
me realise this may be because the address I'm pinging isn't on the 
same subnet and I now have no gateway for those cards or they'll pick 

the gateway facing the ADSL router (which fits with being able to 
ping successfully through that!).  

What about not being able to ping _to_ those cards' numeric addresses 

either?  Again I guess that's because they'll be on a different 
subnet from the machine I'm trying to ping from so that machine will 
try to ping them through its own gateway which is the ADSL router?  

Aha.... but if I add itself as gateway to the internally facing 
card's interfaces entry no change ditto if I give its address as 
gateway to the machine I'm pinging from.  Clearly I still don't 
understand the basics of subnets, broadcasts, networks and gateways 
and I want to understand this before I go the next step to an initial 

iptables set of rules from fwbuilder.

Help please?   TIA,

Chris
PSYCTC: Psychotherapy, Psychology, Psychiatry, Counselling
   and Therapeutic Communities; practice, research, 
   teaching and consultancy.
Chris Evans & Jo-anne Carlyle
http://psyctc.org/ Email: chris@psyctc.org




Reply to: