Hello,
I've been experiencing some strange network issues these days. First of all, network setup:
2x HP gigabit 24 port managed switches
2xHP gigabit 48 port managed switches
2x3COM FastEthernet switches
1xSureCom FastEthernet switch
1x Cisco 2901 router
Address range: 10.10.10.1 - 10.10.11.254
We have some random problems with everything related to Google. Gmail, Google Maps etc, but they might not be the only sites with the problem. We use Google Apps for Business and it's easier to notice when Google Apps Sync fails to work.
We used Google's DNS servers when it first happened, but we switched to our local ISP again and it still happens. They claim the problem is not from them and I tend to agree.
I myself do not have a lot of networking skills and I am in the process of migrating to a Samba4 Active Directory domain.
We do use Samba4's internal DNS forwarders, but the logs don't show anything abnormal in forwarding the requests. And the backup DNS is our ISP.
I'm getting requests timed out to google.com, host name cannot be resolved and so on. The problem here is, I don't know where to begin diagnosing the problem. Most of the other websites/services work properly.
Perhaps someone with Cisco iOS experience can show me a command to run while this problem appears. It first happened last week, today...and who knows when it's going to happen again :)
If anyone has some idea what to do about this, I would appreciate it.