For more information regarding the security incident at F5, the actions we are taking to address it, and our ongoing efforts to protect our customers, click here.

Forum Discussion

Zdenda's avatar
Zdenda
Icon for Cirrus rankCirrus
Jan 17, 2012

OWA - echange web app problem with IE

Hi all,

 

We have OWA running on its own VIP, SSL termination is done on destination servers.

 

We are using quite simple config - round robin, source address persistence, tcp profile with 30 min. timeout.

 

 

We have problem even with displaying login page on TMG. On FF it works quite ok, on IE it mostly doesn't work, occasionally I see login page in also in IE. When I try it directly to TMG server, it works also with IE.

 

 

I am not using any http profile etc.

 

 

Do you have any idea?

 

Thanks a lot,

 

Zdenek

 

config
design

4 Replies

  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Jan 18, 2012
    Hi Zdenek,

     

     

    I'd open a case with F5 Support on this. They'll be able to help you capture tcpdumps to determine what's failing here.

     

     

    Aaron
  • Zdenda's avatar
    Zdenda
    Icon for Cirrus rankCirrus
    Jan 19, 2012
    Ha,

     

    we found the reason of this. It was caused by flooding checking on TMG server. And because we use sNAT on LB, TMG though that is under DOS attack or something like that (because of only one src IP), so it dropped almost all connections.

     

     

    Hope it help to some others

     

    Zdenek

     

  • Techgeeeg's avatar
    Techgeeeg
    Icon for Nimbostratus rankNimbostratus
    Jan 20, 2012
    Hi Zdenda,

     

    Will you share how you found it and what you did to over come this problem????

     

     

    Regards,
  • Zdenda's avatar
    Zdenda
    Icon for Cirrus rankCirrus
    Jan 24, 2012
    Hi, sorry, I don't know the details how exchange guys found this. They have probably running some local FW on TMG server which was dropping connections from the only one source IP - sNAT IP on LB.

     

    And its solved by excluding LB IP from this checking on TMG server.