Occasional random web browsing and nslookup loss- help with debugging?
Hi there, I've got a strange problem I'm trying to get to the bottom of.
Periodically, random machines on our lan lose the ability to web browse. There's no pattern to it: we're using various OS's and it still happens. At the same time, nslookup on the affected machines fail. They spontaneously regain the ability after a seemingly random period of time.
I've done some investigation: I've ruled out pretty much everything on the lan: the workstations can still ping each other, resolve names internally (we use WINS) and ping the gateway (inside interface of a PIX 515E). The PIX seems to know, from using 'show arp', about the IP addresses and MAC addresses of the affected machines, so I dont really think its that; 'show conn' only shows 20-30 connections simultaneously as well.
I'm starting to wonder if its the router thats at fault- its a Cisco 1721, connected to a 2Mb ADSL connection. My working theory is that the router is somehow denying connections outbound for a period; when connections clear, other machines can get a go at connecting. (It's just a theory!)
Can someone give me pointers on checking this theory- any commands I can enter to see whats happening?
Re: Occasional random web browsing and nslookup loss- help with
from your post it seems that all your traffic is getting through the cisco PIX. Is the PIX an unrestricted liscence. If its a limited lic. one, it will stop traffic for more than the specified number of clients. next time of this happens, just give a clear xlate and see whether this solves your problem. If this solves your problem, then its definitely the lic. issue.
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