how to connect virgin media box to cisco 2950 switch

hi I have a virgin media box that I normally set to 'modem/enable' that provides me with a public ip address that I usually plug into my 'isa 2006' firewall.

note:  I have not tried so I am not sure if I can setup 'cbac' as a firewall on the layer 2 cisco 2950, but presumably should be able to set this up on my layer 3 3550.

now I would like to know how to do the both:

question 1.  what do I need to set on a layer 2 switch cisco 2950 to gain internet access  ?

question 2.  as I do not know the public ip address, but I could plug a cable into a server nic card and write down the ip address that does not change for a few months at least, but how would I set that on my cisco 2950 or would I set up dhcp as the public ip address provided would still come from my isp dhcp server   ?

question 3.  what do I need to set on a layer 3 switch cisco 3550 to gain internet access  ?

note: I presume once the above can be done I would then do the following to confirm the public ip address has been detected :

- sh ip int brief
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Craig BeckCommented:
If you use the Virgin box in modem mode a 2950 or 3550 would be no good here... you would need to use NAT somewhere and neither of these switches does NAT.

You can't use CBAC on these either.

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Pete LongTechnical ConsultantCommented:
Craig is spot on - I'm a virgin media customer as well, my home hub is in 'Modem' mode, I have an ASA5505 behind it performing those functions, your cheapest bet would be a cisco 800 series router. if you go down that route here's how to config the router.

mikey250Author Commented:
hi petelong,

I have purchased from ebay a: asa5505
Pete LongTechnical ConsultantCommented:
Good man! There's a ton of ASA articles on my site (link above) if you get stuck :)
mikey250Author Commented:
apologies my internet has been down for a week and only received my router from my isp this morning.  I did not see the (asa articles) but thanks for the advice.
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