I have a 1100AHx2 with v6.48.1 of the firmware and OS (I upgraded as part of the troubleshooting which didn't help). I am having a problem where a single host on my internal network is unable to connect directly to the router intermittently. When the problem is happening that host can still connect through the router to the internet. It just can't use any services on the router like DNS (I have also tested that I can't access the router via ssh, http, or ping). Also, during the problem all other hosts have no problems connecting directly to the router and all other hosts have no problem interacting with the host having the problem.
I noticed the problem soon after I enabled on a service that backs up data from the problem host to S3. Might be something to do with increased traffic (though we are heavy internet users in general and the syncing shouldn't be unusual in any way I can think of). It pretty much happens every time I start the backup.
Some things I have tried:
- upgrading the router OS (this also reboots the router)
- upgrading the router firmware
- pinging the host from router also doesn't work at the time of the problem (though the router can ping other hosts just fine)
- when I do a sniffer tool session on the router, I see the ping requests coming into the router, but the router never responds
- CPU load never seems to break 10%
- Swapped out internal network cable and changed to different ports on both router and Cisco switch (that is only device between router and problem host)
- Adding the host to a queue that limits upload to about 50% of WAN bandwidth
Other notes:
- It eventually starts working again after a while
- I do sometimes have some ping packet loss (5-10%, not total loss like problem host) from other hosts when the problem is happening
- Problem host has bonded ethernet cables between Cisco switch and host.
Does anyone have ideas as to where to look?
Thank you,
Nate