Email connection OK, but Explorer won't connect

[alfietinker]

2 macs and 2 PCs on broadband via ADSL router and 2 hubs. Macs never have a problem and the 2 PCs were fine until we bought new ones.

Since installing the new PCs (windows XP - networked pier to pier to each other), the internet connection keeps going down for a few minutes, then is fine. During this time, the PCs can still access email via outlook, just not the internet (explorer 6). The macs can access everything.

Any ideas? My boss keeps unplugging the router thinking it's the cable and stopping my mac from connecting! (wont accept it's not the router)

 

[Igorian]

Is there any information in the logs on the router?

I know they are new PCs, but router flooding comes to mind and may indicate a browser hack.

What router do you have installed?

What security have you enabled on the PCs?

 

[alfietinker]

Hi, thanks for replying!

Security: Norton Antivirus Internet Security - latest version. Firewall enabled. Windows XP Firewall disabled.

Router: If you mean the brand name it's SMC, ADSL Barricade Router, SMC7401BRA. (Sorry, I'm a mac person)

Where would we find the 'logs?'

 

[Igorian]

Hi

I've had a look at the manual for this router and it's a budget type, so not too advanced. Some details of logs are given on page 63 of the manual, under 'Other Miscellaneous Functions'.

As you router doesn't have a built in firewall, the logs will probably have nothing useful to say.

There are other possibilities. You mentioned hubs in your original post. Do you mean hubs or switches and how are they arranged? Are you getting any collision warnings? Also, Norton Internet Security may be a possibility. If the problem is happening often, try disabling NIS to see if it still persists.

Regards

Ian

 

[alfietinker]

Hi Ian,

Thanks ever so much for doing that!!!!

We'll turn Norton off for a while and see what happens. It only seems to happen every few days though, then seems to resolve itself of its own volition, and its frustrating not to know why.

A bit worried about disabling NIS - we've had possible viruses in the past. Do you just mean the Firewall or the whole programme?

Hubs: The router goes to my hub, which in turn networks 2 macs and peripherals. This then links to a 2nd hub which networks the 2 PCs and their printer. (We didn't set this up, the Broadband man did). This layout didn't change when we installed the new computers.

I'm off to read the manual...

One thing I can't get my head round is why Outlook will still collect emails, and my macs are fine. Can the router only affect certain aspects?

Many thanks.....

 

[Igorian]

Internet explorer uses port 80 and email programs use 25 and 110 by default, which is why I suspected some form of malware hitting port 80.

Also, if you have hubs, they have no 'intelligence' and will send all packets to all ports, whereas a switch can 'work out' what needs to go where, which speeds up connections and lowers collision rates. The fact that your PCs are at the end of this chain might be significant to the problem.

I have known NIS to be problematic. Just turn off the firewall bit and do a few tests. Yes, firewalls are important, but I prefer to see them at the router end rather than scattered across the network on the clients.

 

[alfietinker]

Thank you thank you thank you!!!!!!!!!!!!!!!!!!!!!

Will let you know if this solves it...