Let's say I have the the following configuration on a Cisco router.
Connected and configured into GigabitEthernet8.
VLAN 1 192.168.0.0/24, NAT configured.
Gateway is 192.168.0.1.
Connected to interface FastEthernet0.
Currently not configured.
ISP gives one dynamic IP so "ip address dhcp" should be in place.
NAT must be configured.
What would you do to configure ISP 2 gateway to be 192.168.0.2?
If ISP 1 fails and gateway is not reachable, it must not failover to ISP 2 gateway, also load-balancing must not be active.
The idea is to manually set the ISP 2 gateway on specific computers manually when needed, or through a DHCP server configured inside the subnet.
Current configuration, removed and censored unnecessary stuff.
interface FastEthernet0 no ip address duplex auto speed auto ! interface GigabitEthernet0 no ip address ! interface GigabitEthernet1 no ip address ! interface GigabitEthernet2 no ip address ! interface GigabitEthernet3 no ip address ! interface GigabitEthernet4 no ip address ! interface GigabitEthernet5 no ip address ! interface GigabitEthernet6 no ip address ! interface GigabitEthernet7 no ip address ! interface GigabitEthernet8 ip address X.X.X.42 255.255.255.248 (First ISP 1 usable IP for NAT) no ip redirects no ip unreachables no ip proxy-arp ip nat outside ip virtual-reassembly in duplex full speed auto no keepalive no cdp enable ! interface Vlan1 ip address 192.168.0.1 255.255.255.0 no ip proxy-arp ip nat inside ip inspect Firewall in ip virtual-reassembly in ! ! ip nat inside source list NAT interface GigabitEthernet8 overload ip nat inside source static 192.168.0.143 X.X.X.43 extendable (A few NAT1:1) ip nat inside source static 192.168.0.144 X.X.X.44 extendable ip nat inside source static 192.168.0.145 X.X.X.45 extendable ip nat inside source static 192.168.0.146 X.X.X.46 extendable ip route 0.0.0.0 0.0.0.0 184.108.40.206 (ISP 1 gateway) ! ip access-list standard ADMIN permit 220.127.116.11 0.0.0.63 permit 18.104.22.168 0.0.0.63 ! ip access-list extended FILTERS permit icmp any any permit ip host 192.168.0.143 host X.X.X.43 (Filters to allow NAT1:1 all traffic) permit ip host 192.168.0.144 host X.X.X.44 permit ip host 192.168.0.145 host X.X.X.45 permit ip host 192.168.0.146 host X.X.X.46 ip access-list extended NAT permit ip 192.168.0.0 0.0.0.255 any !
Ideas for the solution,
We know that ISP 2 is at FastEthernet0 and has a dynamic IP, so also since it's only one IP we need NAT outside when more than one client uses the ISP 2 gateway, supposedly to be configured at 192.168.0.2.
interface FastEthernet0 ip address dhcp ip nat outside duplex auto speed auto !
And after that I'm not sure what to do, add an outbound route for Internet access to the gateway for ISP 2? Set the ISP 2 gateway to be 192.168.0.2? But how?
I have found this on a forum, please give it a read:
Be aware that the ISP 2 device is actually a generic Arris router that I have configured to be "bridged", I can set it back to routed and configure it according to that forum post if the setup can't done with the ISP 2 router working in bridge mode.