The following scenario is this:
One LAN with 5 VLANS routed by a L3 Switch.
One SBS 2003 box with internal NIC and external NIC connected to Gateway, mounted with exchange, isa 2004, remote access, ad, dns, dhcp.
Sometimes the Internet service goes down. When this does - and nothing changed except the service being unavailable - the internal network 'stops responding'.
We concluded that the network itself is fine because pinging IP's on different VLANS is ok - however the SBS becomes unreachable and no name resolution, dhcp, pinging to the server works: Destination Unreachable.
If the ISP connection becomes available everything becomes normal again. I can't seem to find logical explanation or solution to this...
Does anyone has a thought on this?
Thank you
dbarroco
