Hi Tan, There are some great papers where layer 2 security issues in ethernet switched networks are faced:
Covery, Sean (Cisco). “Hacking Layer 2: Fun with Ethernet Switches” BlackHat USA 2002 Conference http://www.blackhat.com/presentations/bh-usa-02/bh-us-02-convery-switches.pd f Dugan, Stephen. “Putting 2 and 2 Together: Designing Security into your Network Infrastructure” BlackHat USA 2002 Conference http://www.blackhat.com/presentations/bh-usa-02/bh-us-02-dugan-layer.ppt Cisco Systems Whitepapers "SAFE Enterprise Layer 2 Addendum" http://www.cisco.com/warp/public/cc/so/cuso/epso/sqfr/sfblu_wp.pdf Gill, Stephen (Qorbit) “Catalyst Secure Template” v.1.21 http://www.qorbit.net/documents/catalyst-secure-template.pdf In order to implement security inside/between VLANs you could find many things to implement a defense-in-depth approach: VLAN ACLs, Router ACLs, Network/Personal Firewalling, secure configuration (port security, static arp tables,...), etc. It mostly depends on the risks and level of mitigation to design an architecture that fits your needs (and money!) Regards, ____________________________________________________ __ / / Carlos Fragoso Mariscal C E / S / C A Communications & Operations Dept. /_/ <[EMAIL PROTECTED]> Supercomputing Center of Catalonia CATalonian Neutral Internet eXchange Tlf: +34932056464 Fax: +34932056979 ____________________________________________________ -----Mensaje original----- De: LINKCRAFT [mailto:[EMAIL PROTECTED] Enviado el: martes, 03 de junio de 2003 8:52 Para: [EMAIL PROTECTED] Asunto: VLAN security I have a leased line network with few VLAN configured, may I know how can I implement the security in order to prevent hacking from one VLAN to another VLAN or from internet. There is no firewall installed in the network. Can I implement firewall? If affirmative, how can I protect between each VLAN? They don't have to access to each other. Or should I use IDS or any other tools? Is there any freeware available? Thanks/regards ===== Thanks/regards Tan Yew Kwee Linkcraft Supply & Services HP: 96959406 Fax: 67814648 __________________________________________________ Do You Yahoo!? Send free SMS from your PC! http://sg.sms.yahoo.com --------------------------------------------------------------------------- ---------------------------------------------------------------------------- --------------------------------------------------------------------------- ----------------------------------------------------------------------------