Sendmail / IP Scheme question
 

I was wondering if anyone could give me some evidence to whether or
not using a public IP range on a private network would in fact
confuse things, i.e. equipment,mailservers etc etc...

A client of mine, before they were a client, was given a
192.147.160.XXX internal IP structure which is a public range. To me
this just seems ugly and just asking for trouble. They have a Sonic
Wall firewall, which routes traffic to the sendmail server which sits
at 192.147.160.7. Yes maybe the firewall is smart enough to know that
its on the inside but somewhere along the traffic I bet theres some
confusion going on.

Thoughts?

Thanks.
Joe

i dont see the problem? i wish i had a range of public IP addresses. All you need for the outside is a router that advertises your range and knows where to route traffic, after that, you can treat it like any other network, just with public IP's. It presents more security issues i guess....but it would allow you to run mulitple servers with different IPs rather than having to do port forwarding with 1 IP. Like for instance, I can only have 1 webserver that accepts requests on port 80 because I only have 1 IP, but if i owned a public range of IPs (lets say 192.147.160.xxx) i could have 200+ different web servers. You could even do some classless subrouting and add routers to your network, have many different domains......aaaahh the joys of network setup.....anybody hiring?

oh i wanna point out that the whole classless subrouting stuff can be done with private ips too, you can take a 10.---- and be as creative as you want, only thing is, those IPs wont be seen on the internet.....that's really the only major difference i can think of.

last point, with a list of public IPs you may also want to add your own name servers.

hehe
 

Robert, sorry, while all your info was great, i may have not specified my issue clearly. My client DOESNT own the class 192.147.160.xxx, they just happen to use that range on their INTERNAL network, when they should be using a range like 192.168.xxx.xxx. My question is, does that pose problems.

Joe

ooooooh i think i get it now.....sorry. Yes, that could pose a problem if the gateway they use doesnt SNAT the internal address to the actual address they were assigned. If they start sending out packets onto the internet with that range, then nothing will come back because internet traffic with those adresses wont get routed back to that network. Yes it is ugly, i agree, i'd suggest they change it if possible.

According to ARIN, that IP space belongs to Verio. Is your customer using Verio or someone reselling Verio's IP space as their ISP? If not, it's probably time to renumber.