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How to setup VLAN on Cisco catalyst 3500XL

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glynnj

Programmer
Jun 5, 2002
25
IE
How do you set up a Static VLAN on a Cisco Catalyst 3500XL switch, using the Cisco Switch Manager 12.0 web interface?

I am new to network switches so apologies if this is very basic.

My understanding of VLAN's is that ports in one VLAN are completely separate from ports in another VLAN?

Are VLANs secure, ie is there any way for devices connected to one VLAN to access(Ping, Telnet, etc) devices connected to another VLAN?

Thanks and regards,
Joe
 
VLANs are absolutely secure. There is no way to cross from VLAN to another unless you configure your network to do so.
shnypr-small.gif
 
Not true... we had to open a TAC report with respect to leakage between VLANs that were running IPX on a Cat6500. Certain types of packets were leaking across the boundry. I also remember a issue with a version of IOS that leaked packets in certain circumstances. So VLANs are not absolutely secure.. they are reasonably secure and you should sniff the VLAN to make sure it is as secure as you think.

::snip::
Findings
========
We found that under specific conditions it was possible to inject frames into one VLAN and have them 'hop' to a different VLAN. This is a serious concern if the VLAN mechanism is being used to maintain a security gradient between two network segments. This has been discussed with Cisco and we believe that it is an issue with the 802.1q specification rather than an implementation issue.
:::snip::

entire article:

My own notes from the newsgroup posting here:

MikeS
Find me at
"Take advantage of the enemy's unreadiness, make your way by unexpected routes, and attack unguarded spots."
Sun Tzu
 
In answer to the first question,

here is a link from Cisco on creating and feeding of VLANs on the 2900/3500


Also, I have a tutorial written for the 2900 but it will apply to your 3500:


The tutorial will take you step by step through basic switch configuration and making of vlans with trunks.

MikeS
Find me at
"Take advantage of the enemy's unreadiness, make your way by unexpected routes, and attack unguarded spots."
Sun Tzu
 
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