The IP address is the same as its network address, which is not allowed!

[Guest]

[Goetz]

Hey,
sorry for a n00bish question.

I'm trying to add extra IPs I've got from my Interenet Provider.

For now I've got configured Ethernet Static uplink with following options:

IP address: 87.204.168.224
Netmask: 255.255.255.224
Default gateway: 87.204.168.225
Primary DNS: 87.204.204.204
Secondary DNS: 62.233.233.233

On Endian Firewall panel I go to Network -> Interfaces -> Edit uplink of my main uplink

after that I press: "Add additional addresses (one IP/Netmask or IP/CIDR per line)"
and add following: "87.204.168.227/255.255.255.224"

When I update all changges I get "The IP address '87.204.168.224/27' is the same as its network address, which is not allowed!"

Any ideas how to fix it ?

Thanks in advance for any help

[mrkroket]

Because it's true. Any subnet has 2 special IP's, the first and the last.
The first one is called the network address, it's usually the .0 on netmask 255.255.255.0, but not in other netmasks.

In your case, the 87.204.168.224/27 is indeed your network address, and shouldn't be used.
Your IP ranges are 7.204.168.224 - 7.204.168.255, and neither the first (7.204.168.224) nor the last (broadcast IP:  7.204.168.255) can be used by single machines.

What I don't know is why endian lets you in the first case...
Always use an CIDR calculator for any IP/CIDR stuff: http://www.subnet-calculator.com/cidr.php


More info about subnet Id and broadcast IP on http://en.wikipedia.org/wiki/IPv4_subnetting_reference

[Goetz]

Thanks a lot that worked and explained a lot of thing to me.
I've got twoj more question.

1. In simple way my network looks like this:

ISP Router -> switch -> endian

Red Interface IP: 87.204.168.226
Green Interface IP: 196.192.168.0.1

Two other machines with external IP 87.204.168.23x.
I can't ping any of these IPs (87.204.168.226 nor 87.204.168.23x) only ping that works is router IP (Default gateway 87.204.168.225). Is it because of wrong endian configuration or problem is my ISP's router ?

2. I wanna forward all FTP connections comming from 87.204.168.226 to Green zone computer (192.168.0.16).
I set up my "Port forwarding / Destination NAT" rule like in attachments

When I try to connect via Total Commander via 192.168.0.16 it works but not via external IP 87.204.168.226

I tried tracerouting (using network-tools.com)  my Gateway IP and My Endian IP, while traceroute for Gateway works Endian don't.

Code:

TraceRoute to 87.204.168.225 [gate.stomil-poznan.pl]

Hop	(ms)	(ms)	(ms)		     IP Address	Host name
 1 	  57 	  0 	  0 	     8.9.232.73	  xe-5-3-0.edge3.dallas1.level3.net  
2 	  1 	  1 	  1 	     4.69.145.13	  ae-1-60.edge4.dallas3.level3.net  
3 	  3 	  3 	  4 	     77.67.71.221	  xe-8-1-2.dal33.ip4.tinet.net  
4 	  152 	  152 	  152 	     89.149.186.86	  xe-2-2-0.waw10.ip4.tinet.net  
5 	  162 	  178 	  163 	     77.67.74.98	  netia-gw.ip4.tinet.net  
6 	  149 	  147 	  147 	     83.238.251.99	  warsh002rt22-warsc001rt06.inetia.pl  
7 	  149 	  147 	  147 	     83.238.251.101	  warsc001rt06-poznh002rt09.inetia.pl  
8 	  145 	  145 	  145 	     83.238.249.234	   -  
9 	  146 	  146 	  146 	     81.210.5.76	  poznr001sw01.inetia.pl  
10 	  145 	  145 	  145 	     87.204.168.225	  gate.stomil-poznan.pl  
Trace complete

Code:

TraceRoute to 87.204.168.226 [stomil-poznan.pl]

Hop	(ms)	(ms)	(ms)		     IP Address	Host name
 1 	  0 	  0 	  0 	     8.9.232.73	  xe-5-3-0.edge3.dallas1.level3.net  
2 	  1 	  1 	  1 	     4.69.145.77	  ae-2-70.edge4.dallas3.level3.net  
3 	  3 	  3 	  3 	     77.67.71.221	  xe-8-1-2.dal33.ip4.tinet.net  
4 	  162 	  157 	  157 	     89.149.180.177	  xe-8-1-0.waw10.ip4.tinet.net  
5 	  158 	  152 	  159 	     77.67.74.98	  netia-gw.ip4.tinet.net  
6 	  153 	  143 	  155 	     83.238.251.167	  warsh002rt22-warsc001rt06.inetia.pl  
7 	  145 	  144 	  146 	     83.238.251.101	  warsc001rt06-poznh002rt09.inetia.pl  
8 	  143 	  143 	  143 	     83.238.250.162	  poznh002rt09-poznh002rt12.inetia.pl  
9 	  144 	  144 	  144 	     81.210.5.76	  poznr001sw01.inetia.pl  
10 	  143 	  144 	  144 	     213.17.207.110	   -  
11 	  Timed out 	  Timed out 	  Timed out 	    	   -  
12 	  Timed out 	  Timed out 	  Timed out 	    	   -  
13 	  Timed out 	  Timed out 	  Timed out 	    	   -  
14 	  Timed out 	  Timed out 	  Timed out 	    	   -  
Trace aborted.