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supergper
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Multiple public subnets on ASA

Fri Mar 02, 2012 3:54 pm

I've currently got my ASA (5505) serving a /28 public subnet. I've ran out of IPs, so my DC has issued me an additional /24 subnet that they have routed to my ASA. What needs to be done on my ASA so be able to use these new addresses? I've been trying to search and not been able to find a good answer (some say I shouldn't have to do anything, everything else references NATing, which I currently don't do and would rather not do). The servers I assign these to, I'd like them to have the public ip assigned directly to them.

Any help would be appreciated (I can post relevant parts of my config if it would help)

Thanks

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mellowd
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Re: Multiple public subnets on ASA

Fri Mar 02, 2012 4:02 pm

Wasting an entire public IP on a server which uses a single port is, as the beginning of the sentance states, a waste

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Dinger
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Re: Multiple public subnets on ASA

Fri Mar 02, 2012 4:24 pm

It depends on how your ISP handles things; I have ASAs which handle multiple external blocks of IPs, the only thing I have to do is create the static NAT using the external
IP, no other changes necessary. However, none of my servers have public IPs on them; they have private IPs which I NAT on the firewall to their publics.
"A problem well stated is a problem half solved". (Charles Kettering)

Mendlar
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Re: Multiple public subnets on ASA

Fri Mar 02, 2012 5:01 pm

How is everything connected right now? You say you're not NAT'ing, so where are your servers situated in relation to your ASA? In front of its outside interface?

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texanmutt
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Multiple public subnets on ASA

Fri Mar 02, 2012 6:53 pm

If they are static routing the IPs to your firewalls outside interface address then you only need to add the NAT configurations.


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supergper
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Re: Multiple public subnets on ASA

Sat Mar 03, 2012 12:34 am

Couple points, I'm hosting customer's servers, vps's, etc so port forwarding to a private address is a bit hokey. If they pay for a public IP, they should have a public IP.

Second, I'm (clearly) very green on the networking front. My experience is as a System Engineer, not Network. So bare with me on these rookie questions :D

I may be NAT'ing, but for my current IP range, I don't have to enter anything in my firewall to have them work. If I stand up a new server and assign it one of my current IPs, put it in the outside VLAN, it works. I have one public IP I use for a management server that I do a bunch of NAT/PAT with. So if I need to NAT, will I NAT from the public IP to the same IP? That doesn't make sense to me.

Thanks

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