Slow network, where do I start?

[Andy White]

Hello,

We have a LAN with split into 8 VLAN's and the network seems to of got very sluggish over the last few months and we haven't done any major changes that we think may be causing this.  For example our company uses an App that is hosted, if we use it inside it is very slow to load and our 50mb Internet pipe is hardly being utilised and I have turned IPS off on our ASA just in case this is slowing things down but it isn't.  I tried the App with the same laptop on an ADSL line and it is very fast.  When I put the laptop on the outside VLAN ( ASA to ISP router) it was very fast too, so it must be something Inside.

Should I try and sniff the network? If so what tools are good, wireshark?  Think is the hosted App is in SSL so I'm not sure it it will hide something.

I'm just after some inspirational ideas.

Thanks

[dominic.caron]

Is the application slow in the other internal VLAN ?

If so, problem might be in the ASA, capture a session inside and a session from your outside vlan with wireshark doing the same thing. Check for differences between the two. (retransmit, delay...)

[Kimberly Adams]

Andy,

Have you tried setting up the packet capture on the ASA?  Also, I would look at some of your uplinks and interconnects to check for some of the basics on the interfaces to ensure there are no speed/duplex issues.  Look for errors or discards and look at the interfaces of the ASA to check for erros and such. 

Thanks and Cheers!

Kimberly

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[ALIAOF_]

Is there anything else withint your network that is slow or just this App?