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 From:  Chris Olive <chris at technologEase dot com>
 To:  m0n0wall at lists dot m0n0 dot ch
 Subject:  DNS/DNS forwarding and/or memory issues? (MW 1.1b17 on Soekris 4511 w/32mb mem)
 Date:  Sun, 24 Oct 2004 13:20:13 -0400

I've perused the list back to February of this year, and haven't seen 
this exact issue, so I'll put it out there and see if anyone has any ideas.

First of all, I know just enough about DNS to be dangerous, so if my 
assumptions about DNS don't hold up, feel free to point them out.

I have MW running with DNS forwarding "ON" and "Register DHCP leases in 
forwarder."  I do NOT have "Allow DNS server list to be overridden by 
DHCP/PPP on WAN" and have two DNS entries manually entered on the 
General setup page.  My understanding of how this works I think conforms 
entirely to Manuel's description on the DNS Forwarding page.  My DHCP 
leases receive MW's LAN address as their DNS server.  So DNS resolution 
on these clients goes to MW and MW uses its forwarder, cache, and manual 
entries to resolve DNS requests.

The manual entries are listed in the following order: my outside 
provider's primary DNS and my secondary DNS entry is another machine on 
my LAN which has zone entries and a DNS server running for my local 
domain which uses ".local" as its domain name suffix.  Since most DNS 
requests are for outside addresses, I expect the primary DNS (pointing 
to my provider) will resolve these quickly while internal addresses will 
require two lookups -- one to my provider's DNS and one to my internal 
DNS which resolves .local domain name requests.  The internal DNS is 
also a caching DNS (which I don't expect has many outside addresses in 
its cache -- I would expect these to be in MW's DNS cache), and has 
forwarding for my outside providers primary AND secondary DNS.  So I 
think my DNS is covered, and most of the time, this setup works to 
perfection (and I assume internally as I describe above).

Occasionally however, over time, it appears the DNS Forwarder on MW goes 
arye and internal address DNS requests for my .local domain do not get 
resolved.  It appears that cycling the DNS forwarder on MW solves the 
problem for a week or so and then the problem shows up again.  I see 
there have been "issues" logged here and there regarding the DNS 
Forwarder on MW, but nothing that matches my situation.  Perhaps it's 
just a memory issue?  I'm running MW 1.1b17 on a Soekris net4511 with 
32mb of memory.  I'm suspecting this to be the culprit in some way.  
Perhaps someone can confirm?  Also, any comments on my DNS setup overall 
are welcome.  It makes sense to me, but perhaps there is a better way to 
do it.

Chris Olive
chris at TechonologEase dot com