Cisco 877w issue

ThorpedoUK

ThorpedoUK

ThorpedoUK

Associate
Joined
15 Sep 2009
Posts
839
Hi guys

Wondering if we have any seasoned Cisco experts on here that might be able to help me with a few weird problems I am experiencing with my 877w router.

Basically I am building up a CCNA lab (I know about packet tracer but since my new job means I will inherit some CISCO kit, I need to be able to use the hardware also - they are sending me on a CCNA but I want a head start and I like messing around with labs at home too) and replaced my Be Box (Be Unlimited ISP) with a 877w which I have configured and is working, however there are a couple of weird issues that I am experiencing:

1. When browsing the web using either wired or wireless often when I click a link either to download or stream something I instantly get "Page cannot be displayed" (I currently have the firewall on "medium" setting on the router), it is not the link that is not working!

2. In google for example if I search for a keyword, when I click to select a link (to go to that website) after the first click it refreshes the screen so I actually have to click a second time and it takes me to the website. This is not a PC problem as it does not do that on my other router, very weird.

3. The wireless drops after a while, but following 10mins it comes back up.

Any ideas?

It would be cool if you could give me some hints rather than just say do this and this so I could try and figure it out myself (assuming you know what this is down to), I'm thinking the weird browser issues are probably the firewall so will try disabling that temporarily later :D

Doubt this is relevant but I am running Netflow on the DSL interface, not sure if this causes a huge overhead, but it does not appear to looking at resources etc

Cheers!
 
Last edited:
Did some of it using the web interface but mainly only the firewall, netflow and some firewall rules.

Worth doing all of it from the CLI then?

Thanks
 
A quick hint on netflow and DSL on Ciscos, the IN traffic is captured on the Virtual Access Interface and the OUT traffic is captured on the Dialer Interface. If you used the SDM it should (I assume) take this into account. When manually configuring netflow, its easily missed.

Try disabling the firewall. If you are using NAT this will provide a reasonable level of protection to the internal network anyway.

The wireless shouldn't fluctuate too much, are there other networks in the area that over lap the channel you are using? Try changing the channel.
 
The intermittent page loads could possibly be an MTU issue...

IIRC Be retail is PPPoEoA so you might want to try adding the following commands to the dialer interface:

Code: 
ip mtu 1492
ip adjust-mss 1452
 
Last edited:
Thanks guys, awesome suggestions - CLI it is! :D

Will erase and rebuild it tomorrow.

So how do you know that it could be the MTU thats causing the page issues? is this just an experience thing or should I be able to figure this out myself?

How do you run debug mode, I could google this I guess but wondered if you wouldn't mind giving me a quick run down on tracing // debugging commands so I could actually see why the page issue is happening, how would I debug it in a real live environment?

Thanks again much appreciate your guys help
 
By the way can I ask a "sort of" related question, I was wondering if it would be possible to route analogue calls through my 2611XM (maxed memory) using a CISCO VIC-2FXO Voice Module to a CISCO IP phone upstairs (running off POE, the POE switch I still need to buy and the phone but I want to play around with it), is this possible? essentially I'd like a CISCO IP phone for both SIP & analogue calls, any ideas what I would need to do this or is it simply that one module?
 
ThorpedoUK said:
So how do you know that it could be the MTU thats causing the page issues? is this just an experience thing or should I be able to figure this out myself?
Click to expand...

Bit of both, and the fact that I know BE is effectively PPPoE and those symptoms could suggest it. I generally don't touch SDM (spawn of satan as far as I'm concerned) if I can help it so it may have added those commands for you but I wouldn't know for sure.

ThorpedoUK said:
How do you run debug mode, I could google this I guess but wondered if you wouldn't mind giving me a quick run down on tracing // debugging commands so I could actually see why the page issue is happening, how would I debug it in a real live environment?

Thanks again much appreciate your guys help
Click to expand...

Use "debug ?" and I'm sure you can go from there - "no debug all" to turn it all off again.

In a live environment you have to be slightly careful what options you turn on as some of them can generate a LOT of data very quickly.
 
Last edited:
I can kind of appreciate what you mean about the SDM, I made a minor firewall change and it said it was writing something like 7-10 commands to the router, I was like whhhatttt! I'll stick to the CLI then.

Cool - thanks, I may put it back on as is and run the debug command to see if I can fix it as is, then rebuild, I would like to run the firewall commands through the CLI also.

I have a ASA 5505 waiting to go in the mix as well but thought I'd better try and "learn" the 877w first!

Cheers
 
You must log in or register to reply here.
Back
Top Bottom