Re: 2 interfaces and "Ignoring MISS from non-peer"

Ernst Heiri wrote:
>
> > One of my parents has 2 interfaces. When I configure my Squid to use my
> > parent's interface A, I get lots of "ignoring MISS" in cache.log, with
> > the interface B IP address. Then a few minutes later, I get a "Detected
> > DEAD Parent".
> >
> > However, when I configure Squid to use my parent's interface B,
> > everything is ok: no "ignoring MISS" and no "Detected DEAD Parent" (at
> > least after a few hours).
>
> I guess it may be a DNS configuration problem and a squid
> implementation problem?
>
> 1. if your proxy sends an ICP request to your parent, it has to ask
> the DNS for its IP-Address. Lets say it gets the IP-Address of
> interface A.
> 2. the parent really receives the ICP request on interface A, but
> 3. it replys an UDP_MISS on interface B (with the other IP-address)
> 4. if your proxy receives the reply from the parent it makes a
> reverse-lookup with the IP-address of interface B and doesn't find
> the host name of the parent (because of an inconsistent DNS configuration).
> So your proxy ignores the MISS from the parent and believes the parent
> is not answering because it is DEAD.
>
> Solution:
> - check the DNS configuration of your parent so there is correct
> reverse lookup for all interfaces possible.
>
> - squid could be improved so it replys UDP requests on the
> same interface it got the request.
> (the same way like bind is doing it)
>
> Ernst

I put 2 lines of "cache_host ... parent", one for each different name
(interface)
of my parent. With this, I no longer get "Ignoring MISS from non-peer"
messages.

But after a few minutes, one of the parents becomes DEAD. Sometimes it's
A,
sometimes it's B. The other one survives :)

I checked the DNS and the reverse-lookup is ok, however, the reverse of
interface A only contains the name "A", not 2 names. Do you suggest
that the reverse of each interface should point to the 2 possible names?

I checked the reverse of 2 parents at nlanr and they point to a
completely
different name that the one in my squid.conf. And I have no problems
with those parents.

I wonder if the parents at nlanr have more that 1 interface to the
Internet.
I know they are on vBNS.

-- 
Marc Delisle                              
Service Informatique                              
Collège de Sherbrooke      
Québec.  819/564-6223