The internal address of the primary Domino mail server is 192.168.1.2. It seems some folks have their home router set to assign that address. When the user brings his laptop into the office the address is recognized as unavailable and the laptop is assigned a new address. It takes about 2 seconds (see DHCP server log except below).
6:48:40 AM DHCP:DHCPDISCOVER from 00:16:d3:25:15:ab via 192.168.1.67
6:48:41 AM DHCP:DHCPOFFER from 192.168.1.208 from 00:16:d3:25:15:ab from 192.168.1.67
6:48:41 AM DHCP:DHCPREQUEST from 192.168.1.208 from 00:16:d3:25:15:ab via 192.168.1.67
6:48:41 AM DHCP:DHCPACK from 192.168.1.208 from 00:16:d3:25:15:ab from 192.168.1.67
But that's enough for anyone working on a mail message in their server replica to get a "Server not responding". The Notes client does not offer to switch to the cluster mate. Instead the user must hit Ctrl-Break, and can then continue working normally.
Anyone else seen this? Is this working as designed?
David N Schaffer February 17th, 2010 11:22:01 AM
Your issue appears to be that your laptop user is poisoning your switch table. Your hopefully not still using a hub, if so, ditch it immediately as hubs don't even have mac / port forward tables. You'll see immediate performance gains. If you are using a switch, you have a couple of options to try:
1) Change your server's IP address. Better yet, use a 10.xxx.xxx.xx IP scheme or a 172.16.xxx.xxx and never use a scheme from 192.168.xxx.xxx since they are the home network staples. Now your clients will come in and have an IP address that is nowhere near a similar address of any of your servers / services.
2) Move you clients to a switch further away from the servers. Keep your DHCP and Domino servers on a primary switch and connect that to the router (gateway), and your clients on another switch connected to the same router (gateway). The gateway will be forwarding the request to the dhcp server and this may buy you the time you need to get a new ip out to your client without messing up the route tables in your switch.
Reid, thanks for the comments.
Switching the server IP isn't much of an option; the numbering scheme is very long in the tooth and it would be hard to change it everywhere.
Topography is servers connected to each other by a single switch which connects into the top of the switch stack; user machines connect lower down in the switch stack. I'll have to check where the DHCP connects; that might be a way to control to the timing.
That's always the way of it. Things are hard to change, depending on your dhcp server, you can try looking at some of your bootp settings as well. Some adjustments there may help. You do however, know the offender's mac's, so you can just offer to have them bring in their home routers and you can do them (mostly you) a "favor" and reconfigure their devices for them.
It took me a long time to identify the user with the home router set to overlap the servers. Now we can change it.
For what it's worth, Netgear's default is apparently to start assigning at 192.168.1.2.