We have the SRX 320.
Our ISP provides several external static IP addresses from the 95.78.228.208/29 subnet.
ISP routes these addresses from the gateway 95.78.251.254 to the address 95.78.251.27, which also needs to be configured on our side.
ISP is connected to the interface ge-0/0/0.
I guess that the addresses 95.78.228.208/29 should be configured on some internal virtual interface, but I did not find anything suitable in the documentation.
I tried the configuration where address 95.78.251.27 is configured on the interface ge-0/0/0.0 by using proxy arp.
Something like that:
set security zones security-zone untrust-isp-1 interfaces ge-0/0/0.0 set interfaces ge-0/0/0 unit 0 family inet address 95.78.228.209/29 primary set interfaces ge-0/0/0 unit 0 family inet address 95.78.228.210/29 set interfaces ge-0/0/0 unit 0 family inet address 95.78.228.211/29 set interfaces ge-0/0/0 unit 0 family inet address 95.78.228.212/29 set interfaces ge-0/0/0 unit 0 family inet address 95.78.228.213/29 set interfaces ge-0/0/0 unit 0 family inet address 95.78.228.214/29 set security nat proxy-arp interface ge-0/0/0.0 address 95.78.251.27/24 set routing-instances isp-1 instance-type virtual-router set routing-instances isp-1 interface ge-0/0/0.0 set routing-instances isp-1 routing-options static route 95.78.251.27/32 next-hop 95.78.251.254 set routing-instances isp-1 routing-options static route 0.0.0.0/0 next-hop 95.78.251.27 resolve
But this configuration didn't work. The list of routes to the 0.0.0.0/0 for the routing-instance isp-1 was empty.
root@orn-gw-01> show route table isp-1.inet.0 0.0.0.0/0 exact
Therefore pings to google dns returned a "ping: sendto: No route to host" error.
I suspect that I'm doing everything wrong 
Could you help me how to configure this in the right way?