Weird website problem - help me understand what to check next…

  • Hi all,

    Got a really weird one for you.  For several hours a day I have no/intermittent access to our company website.  At first I put it down to crappy hosting and didn't think much of it but after several months of messing around I can't figure out why it keeps dying apart from I think something odd is happening with pfsense.


    • Website starts to get slower and slower to load up, eventually times out
    • Usually happens between about 13:00 - 17:00 UTC each day
    • Occasionally will load as normal with a big delay (normally after I've given up trying for at least an hour)

    Things that still work:

    • Pings fine
    • Traceroute fine
    • Every other website I've tried works fine

    Where it gets weird:

    I have 4 internet lines going into my pfsense box.  If I route all traffic out via a different line sometimes it solves the issue, sometimes it makes no difference.

    Where it gets weirder:

    If I plug directly into the ADSL router in front of pfsense, the website works fine.

    Things that might cause issues:

    I have a split DNS on the company website domain so that I can redirect webmail to the internal server when you're inside the building.

    Reasons why I don't think split DNS is to blame:

    • The firewall doesn't use the internal DNS server at all.  I left it with the standard ISP assigned DNS + Google DNS servers.
    • If I manually set a LAN client to use say Google DNS and ignore everything else, it still doesn't work.

    So any ideas? I'm running an older 2.01 pfsense box.  The plan is to rig up a test machine on 2.1 over the next day or two to see if that solves the problem.  Just in case ADSL routers are to blame I've got a few ADSL modems on order however I already have 1 of my 4 lines with a standard modem (not router) and I have the same issue going through that.

    Can anyone recommend any logs I can look at or diag tools I can use to try and see what is happening?