Things point to Cradlepoint don't they? I've used Digi ConnectPort with lots of success. Or go with the 3G-Wireless HWIC card or ask VzW for a static IP address. The last thing would be to use object tracking in conjunction with EEM to solve your problem.
Regards, Luan Nguyen Chesapeake NetCraftsmen, LLC. [W] http://www.netcraftsmen.net [M] [email protected] [Blog] http://cnc-networksecurity.blogspot.com/ -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Bob Tinkelman Sent: Friday, January 16, 2009 11:35 AM To: [email protected] Subject: [c-nsp] Forcing dhcp lease renewal For a cisco router with an interface like this: interface FastEthernet0/1 description Verizon EVDO via Cradlepoint CBA250 ip address dhcp I'm looking for a way to force the router to issue a dhcp lease renewal request. I can do this manually, for example via config term int fa0/1 shut no shut exit but I'm looking for a way to trigger this automatically. (Or possibly I'm trying to solve a problem in the wrong way.) Background: We have a good many customers with T1 or multi-T1 service, and with fall-back routing configured over a "cheap path", typically a dynamic-ip cable-modem service or dsl. Our configs use a combination of gre-tunnels (to preserve customer-site address ranges) and sometimes object tracking and policy routing (often to direct web requests to a higher-speed cable-modem service in cases where NATing is acceptable). We've been doing this for a good while and have a set of configs that provide pretty solid service. I have been testing, in a lab environment, a configuration to do the same thing with Verizon's EVDO service using a Cradlepoint CBA250 (Cellular Broadband Adapter). It's not a router; just a "pass-through device". The same configuration that we use with dynamic-ip cable- modems works. However, several times/day, things "break". Output of "show interface", "show dhcp lease", etc., show that the cisco router doesn't think anything's changed. The interface has the same dhcp-assigned ip address and default gateway. But the default gateway is no longer pingable. Doing a "clear int Fa0/1" doesn't help. A "shut" and "no shut" will cause the router to issue a new dhcp request, get a new (and different) ip address and gateway, and start working again. My current working hypothesis is that the EVDO link between the CBA250 and Verizon was interrupted, possibly very briefly, that Verizon noticed and invalidated the dhcp lease, but that no indication of this reached the router. It's a weak hypothesis. I'm bothered by the fact we've never seen this problem with similar cable-modem setups, e.g., with Time Warner and with Cablevision. I've sent email to [email protected] even though I really don't see how their equipment could be involved. I could use object tracking to discover when the link over EVDO stops working. But I'm not sure what do to with that info. Is there a way to force a new dhcp request to go out based on object tracking? (To date, I've used object tracking mostly to enable/disable specific ip route commands.) I have the strong feeling that I'm trying to solve this in the wrong way, and that if I really understood what was going wrong, I'd be working in a different direction. So, any hints would be much appreciated - Bob _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
