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shorewall-users: Re: [Shorewall-users] Please help diagnose data

Re: [Shorewall-users] Please help diagnose data transfer problem

From: Casey Bralla <Casey_at_nospam>
Date: Tue Dec 06 2011 - 16:31:19 GMT
To: "Shorewall Users" <shorewall-users@lists.sourceforge.net>

Interesting problem. Here are some things you might like to check (beyond
what you've already done).

1. Try SFTP from different servers behind the firewall. It may be
something as simple as a bum network card on one of your servers.
(although I would have thought your logs would have shown that)

2. Run Wireshark (or something similar) to listen in to the network
traffic during the transfer. You might get clues to the actual
transmission, or see some other disruptive traffic.

3. Watch the blinken lights and see if the network is congested, or just
something wrong with the transmission rate.

4. Verify that you don't have an IP conflict (2 devices with the same IP)
fighting for control.

Good luck!

> One other piece of information...
>
> This "blockage" seems to be only for download (from server to
> internet).
>
> I tried sftp tests uploading data (from internet to server) and the
> transfer is fast as expected. But try to download and we're back down
> to ridiculously low data rates.
>
> :-(
>
> At Monday, 12-05-2011 on 23:52 "Ricardo Kleemann" wrote:
>
> Hi,
>
> I don't know what's happened suddenly to my firewall.
>
> I see no sign of device trouble, nothing very telling in my logs. All
> of a sudden my data transfer rate has dropped drastically, but this is
> only for servers behind the firewall.
>
> I've rebooted the servers, rebooted the firewall, rebooted network
> switch.
>
> For data transfer testing, I run sftp to the server shorewall is
> running on. And I get very fast transfers as expected.
>
> However if I attempt sftp to any server behind shorewall (in the loc
> network) then I get ridiculous 10KB/s. This just happened suddenly and
> I have not been able to figure this out.
>
> On the shorewall server, I look at the eth devices and I look at
> /var/log/messages and I don't see any evidence of problems. I'm not
> seeing any sort of driver or kernel errors logged.
>
> What could be "blocking" the transfer? How could I properly diagnose
> this?
>
> I'm really lost at what could be happening here.
>
> I appreciate any help.
>
> Thank you
> Ricardo
>
>
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-- Casey Bralla Chief Nerd in Residence The NerdWorld Organisation ------------------------------------------------------------------------------ Cloud Services Checklist: Pricing and Packaging Optimization This white paper is intended to serve as a reference, checklist and point of discussion for anyone considering optimizing the pricing and packaging model of a cloud services business. Read Now! http://www.accelacomm.com/jaw/sfnl/114/51491232/ _______________________________________________ Shorewall-users mailing list Shorewall-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/shorewall-users