Microsoft Loopback adapter drops packets. RRS feed

  • Question

  • Hi,

    I'm using Microsoft loopback adapter on my windows 2003, it is used to achive local connectivity between severl modules on the same host ( - is not usfull since it does not have a NIC that I can bind to with a sniffer).
    So, whenever I reboot the machine I can see the adapter is up and running, my services are working and sockets are in listening mode on the loopback adapter and on the regular NIC as well (I'm binding to all NIC's).
    But clients that connect get stuck, after troubleshooting it - I realized that the loopback adapter is the problem. connections can be established (3 way hanshake works) but once the connection is established - all the data packets followed are getting dropped.
    Some how disable and enable to the Loopback adapter solves the problem - but the symptom is regenerated every restart of the system.
    BTW, no personal firewalls installed or TCP/IP filtering is active.

    Does anyone have any idea what's wrong? I've tried to look with procmon and there are no denies.
    I'll appriciate any ideas/solutions.

    Thanks in advance,
    Tuesday, March 17, 2009 10:03 AM

All replies

  • I just figured out that one of the services is the cause, it is related to the way it utilize the NIC.
    Tuesday, March 17, 2009 1:51 PM