Cable router and servers lock-up

[threedots]

The Setup:

I have 3 Win2K servers servicing a 55-node workgroup. (Active Directory not yet implemented.) All networking is switched, 100Mbps cards all set at full duplex servers and clients. I have a Linksys BEFSR41 cable router connected to a cable modem and a static IP address bound to the modem's MAC address by the ISP. All clients are Win98SE. DHCP is disabled and I statically assign all client-side IP's. Standard local LAN IP range of 192.168.1.1-253 with single subnet. Intranet server opened to outside access through port forwarding on Linksys Router. NICs on the servers are all 3Com's, and appear to be functioning properly.

The Problem:

Periodically (about every 3-5 days) I lose all connectivity through the router for internal/external services. At the same time I lose the ability to reach the Intranet server from the outside. Additionally, I cannot ping the static IP assigned by the ISP at this point, which should be bouncing off the modem, not the router. When this happens, I also typically see that all three servers have locked up. I reboot the servers and power down/power up the router, and everything is fine again until the next failure. This has been happening with consistency for several months. Linksys appears incapable of providing a solution (router has latest firmware installed). I never have to reboot the modem to solve this problem, only the router and 3 servers. The modem is DOCSIS 2.0 compliant (and backward-compatible, of course, to 1.1 and 1.0).

The Solution?

Is this a throughput issue on the router? Firmware issue? Other problem? Do you recommend another router, and if so, why?

Please post your answers/suggestions/requests for more info. You've helped me out before, can you do it again?

Threedots

 

[Accessdabbler]

One of the servers is dual-homed to connect to the network AND the router?

The ISP records the MAC address of the ROUTER not the modem. The WAN side of the router is what gets the IP address, not the cable modem. It's possible that the MAC address the ISP has on file is not the same as the MAC address of the router's WAN side. In this case, the router should have the option to CLONE the MAC address. You simply turn on cloning and put the MAC address in the box that the ISP is expecting.

 

[manarth]

Access - it's probably not MAC cloning in this case; in my experience most ISPs implement this as an immediate block - in other words, without the correct MAC threedots would NEVER be able to get online.


Threedots - firstly, I think it's a LAN issue of some description, I don't think your router is at fault (after all, your servers are locking up).

Some troubleshooting steps...
- take a look at your servers' logs for that time, see if there's any unusual activity
-next time they lock up, unplug the LAN from the router, recycle the router, THEN try and ping your WAN IP (from a seperate internet connection). This should (hopefully!) seperate it to either a server issue or a router issue.

My best guess is a server issue - if only because all 3 servers are simultaneously locking up.

Good luck!

<marc> i wonder what will happen if i press this...[ul][li]please give feedback on what works / what doesn't[/li][li]need some help? how to get a better answer: faq581-3339[/li][/ul]

 

[gunthnp]

I might be the modem not getting updates from the ISP if they are trying to send update info to the modem and it can't get passed the router that might lock it up a lot of ISP send out speed updates every week or so becuase people try to uncap their modems and so they do it to put it on the right speed

gunthnp
Have you ever woken up and realized you where not alive.

 

[manarth]

gunthrop: threedot's setup SHOULD be

isp --- modem --- router --- LAN

so this shouldn't be an issue.

<marc> i wonder what will happen if i press this...[ul][li]please give feedback on what works / what doesn't[/li][li]need some help? how to get a better answer: faq581-3339[/li][/ul]

 

[bcastner]

You need to enable logging on the router and start collecting statistics.

My own guess is that the router table becomes full, it only has 512k of RAM shared with the store-and-forward responsibility of the switching.

I think you need a fancier router.

 

[gunthnp]

its a cable modem check the Resistance on the line it need to be in range of 10 ohms

gunthnp
Have you ever woken up and realized you where not alive.