Cisco ASA Multiple ISPs, Multiple Public IPs

[ajay_dand]

Hi,

One of our customer has 3 different ISPs and he's using the Public IPs provided by these different ISPs for his Public facing servers. Obviously, each ISP is providing the IP addresses from entirely different address space. Can the same setup be used to bring the servers behind a Firewall and allow the Public IPs to be NATed or otherwise using a DMZ? If so, can you please explain with a sample config? Thanks in advance.

Ajay.

[5220]

Hi Ajay,

Yes, it is possible, but you need to have all the 3 IPs routed through a single ISP:

MAIN ISP----ASA---- IP ISP 1

---- IP ISP 2

---- IP ISP 3

The MAIN IPS will need to route on the internet all the 3 IP/Subnets

The config is simple:

static (inside1,outside) netmask 255.255.255.255

static (inside2,outside) netmask 255.255.255.255

static (inside3,outside) netmask 255.255.255.255

The inside1,2,3 are VLANS created on the ASA inside interface.

Please rate if this helped.

Regards,

Daniel