Packet sniffer sees ping, but machine does not reply.
Posted on 2011-02-19
We have been having some crazy intermittent connection problems in a remote office for a few weeks now. The internet connection will drop out for about 30 seconds about 3 times a day, more at night. We have been trying 1000 different things, but the biggest result was from the packet sniffer. During the ‘outage’ we would send pings to the machine in the office running a packet sniffer. The sniffer will pick up the ping requests but the machine will not respond to the ping request during the outage. All of the machines will not respond to pings during this time. Once it’s over, everything is back to normal. The sniffer appears to show normal activity. The switch, ISP, router, VPN, etc all respond to pings during this ‘outage’.
Any help or direction would be greatly appreciated.
Problem is in remote office. Network has about 7 pc’s on it, connected to an HP Procurve switch. That goes through a Cisco Pix to an Adtran Integrated Phone/Internet router located in the remote office. Hardware VPN to Cisco ASA in Main Office. Cisco Pix in remote office passes out IP’s, DNS #1 is set to Main office, DNS #2 is set to ISP. Pings are sent from Main office to remote office. Systems run XP. Server 2003 and DNS are in main office.