Re: [gentoo-user] Can't ping remote system

[Grant <emailgrant@gmail.com>]

>> > +1 on Alan's hunch.  I have not used Squid to comment on the specifics
>> > and also Grant stated that another proxy gave him similar symptoms.
>> > From my limited knowledge a proxy could be stalling because of cache
>> > configuration problems, like running out fs space, or inodes and also
>> > running out of memory if it has to process simultaneous requests from
>> > too many clients at a time. If the problem also manifests when the
>> > clients are within the same subnet, then this is unlikely to be a
>> > network issue.
>>
>> Which hunch was that?  I snipped a lot above but I couldn't find it in
>> there.
>
> It was Alan's statement that this problem is not related to your AT&T router.
>
> I have to come back to this.  I tried the www.google.com/nexus/ you mentioned
> and noticed that the page eats up 1.3MB to load fully, before it starts
> downloading a flash video.  So seems to be a relatively large amount of data
> that brings up this problem and this could point to tcp window scaling.

It also happens on very lightweight sites, but never on
squid-cache.org for some reason.

>> echo 0 > /proc/sys/net/ipv4/tcp_window_scaling
>
> This is typically enabled, but if you notice that a connection stalls and then
> later on it works fine again, it could be related to a firewall/router not
> responding as it should to tcp_window_scaling.  In this case disabling this
> would fix the problem when traversing problematic nodes.
>
> If you saw no difference, this suggests that window scaling is not an issue.

I just tested again and 'echo 0 >
/proc/sys/net/ipv4/tcp_window_scaling' on both the client and server
did not fix the stalls.

> I would start with the simplest tests first, which involve isolating suspect
> system components one at a time.  Trying to use the same laptop-desktop
> machines within the LAN, takes the router out the equation - full 1500 byte
> MTU will be used by both laptop and desktop.

OK I will try this as soon as I'm back in that location.

Thanks a lot,
Grant