intermittent and partial network failure on laptop w/DSL

Hi-

I have a Dell Latitude LS400 laptop running RH9, attached via 802.11
wireless to a netgear access point and then to a netgear DSL modem using
the PPPoA protocol. Mostly, it works fine. However, intermittently I get
the following errors:
- mozilla gets stuck 'resolving host' (but nslookup works fine)
- cvs access to a networked 'pserver' repository fails -- no messages,
but nothing happens; it just stops and needs ctrl-c or sometimes
ctrl-z (but there's not complete failure; some single-directory
accesses with '-l' work)
- sending mail via my ISP's smtp server fails (at least under XEmacs
vm mailer)
- scp fails when attempting to copy to certain network destinations
(but it fails at the end: it gets to '100%' according to the
indicator, hangs there, and if I check there's a zero-size file on
the remote machine).

I think (but am not sure) that these things may not happen when
connected directly to ethernet at work, so it may have to do with my
adsl hookup.

It's certainly possible that all of these things are unrelated
(especially the first, which is a reported but rare mozilla bug), but it
seems fishy to me. Any ideas?

Andrew

Hi All-

> I have a Dell Latitude LS400 laptop running RH9, attached via 802.11
> wireless to a netgear access point and then to a netgear DSL modem using
> the PPPoA protocol. Mostly, it works fine. However, intermittently I get
> the following errors:
> - mozilla gets stuck 'resolving host' (but nslookup works fine)
> - cvs access to a networked 'pserver' repository fails -- no messages,
> but nothing happens; it just stops and needs ctrl-c or sometimes
> ctrl-z (but there's not complete failure; some single-directory
> accesses with '-l' work)
> - sending mail via my ISP's smtp server fails (at least under XEmacs
> vm mailer)
> - scp fails when attempting to copy to certain network destinations
> (but it fails at the end: it gets to '100%' according to the
> indicator, hangs there, and if I check there's a zero-size file on
> the remote machine).
>
> I think (but am not sure) that these things may not happen when
> connected directly to ethernet at work, so it may have to do with my
> adsl hookup.

Well, for what it's worth, I think I've solved my own problem --
although I don't quite understand why it works. My ADSL ISP has
advocated changing my 'MTU' setting, first down to the lower setting of
1458, and more recently back up to 1500 as it resolved issues with BT
(British Telecon). Setting the router back to 1500 seems to fix most of
these problems.

But I don't quite understand why: the MTU is set on the ADSL modem,
while the problem only seemed to manifest itself when I connected
through a second (wireless) router attached to the modem/router. I don't
understand why this should have caused the problem, and why it should
have fixed it!

But anyway, it *does* seems to be fixed.

Andrew