Question about Cisco 3548 XL Switch

[traderjm]

Hi everyone, first time poster here so please be gentle. In reading the forums it seems there is a large group of helpful folks in here and god knows I need some advice.

I have been drafted to look after some Cisco equipment and quite frankly I've never worked with them before I can see there is quite a learning curve and I will get at it as I know I can't rely on others to always solve any issues, plus of course the time factor in doing things oneself plays a big part. Not waiting for replies, etc... having said that.... help

I have a Cisco 3548 XL, that has been flashed up to the latest version of IOS, when we got it, it had a whole whack of old Vlans setup on it that have now been removed. We've set our own password and domain, and host name etc... all in all it seems to be running fine. I just have a few minor little issues I would like some feedback on.

First thing is it seems to run perfectly for hours on end, then for no reason I can see, meaning I don't know where to look, it seems to just go into ultra slow mode... some pages won't load (it's being used mainly for a small network and a lot of people surf the net through it) some load very slowly, to the point that if I remove them from the switch and plug them right into the DSL line everything is fine..so I know it's the switch, where how what should I be looking for to track such an issue?

Secondly, when I am logged into the switch via the web interface and I check the port settings I seem them ALL set to Auto for duplex and Auto for Speed, which I assume is ok, but under the heading of "Port Fast" they are all set to disabled, is that ok?

I am about to team a pair of Intel NICs and set up an etherchannel on the switch but before I get too far into that I want to see if I can get some suggestions for what are considered to be normal things to check out about the operation of this unit... just in case there is something not quite right...

Thanks in advance for any/all suggestions.

J

[Jay]

Portfast disabled is the default setting for spaning tree. As for the slow page loads are you 100% sure its the switch that is the problem, are you forwarding between VLANs?

[traderjm]

Portfast disabled is the default setting for spaning tree. As for the slow page loads are you 100% sure its the switch that is the problem, are you forwarding between VLANs?

Thanks for the quick reply,

So should I leave "port fast" disabled? What are the pros/cons?

I am 100% positive it's the switch. Because through any other device, an old 2924, a netgear switch, basically any other device I have to use here everything else works fine during the time the 3548 slows down..

I am not doing anything fancy. Basically it's a small domain with one Windows 2003 DC and about 21 clients machines, ONE VLAN, the switch has an IP and subnet mask but NOT gateway set, might that be an issue?

So all the machines, server and all clients plug into the 3548 as well as a DSL modem and everybody uses everything in the network that way.

I was searching around hoping there was a document I could find somewhere that lays out a good quality default group of settings for these switches but that's asking too much I think as they are so very complicated.

Thanks again.

[Jay]

If you have no other switches you can turn portfast on but it will only reduces the time it takes for the port to come up (Orange to green) You must make sure that no one puts another switch on the network though or you can casue loops and with portfast on it will nto detect the loop.

[traderjm]

If you have no other switches you can turn portfast on but it will only reduces the time it takes for the port to come up (Orange to green) You must make sure that no one puts another switch on the network though or you can casue loops and with portfast on it will nto detect the loop.

Ahhhh ok so really no effect on the daily operation of the unit, ok disabled it is... there are no other switches on this network, hmmmm actually now that I think it about there is a small switch upstairs... forgot all about that one :-)

Thanks again.

[Jay]

this sounds like a duplex missmatch to me.

[Moby-Dick]

try forcing the ports and your client nics to 100/full ?

[badass]

get on to the switch and post the output from show run here.
reset the counters and do a show int for any of the ports that have ran slowly.
If you need to know how to do those things, let us know

[badass]

I don't know about 3548's but on our 3750G's you can set the ports to portfast but the moment they detect a BPDU, they shut the port down.
If you are going to have different port settings for different ports, particulariloy if you have switches connected, make sure you physically (with stickers) label something near the switch that indicates this.