Why a Default Gateway of 10.X.X.X

[stvhull]

Hello.
on a Bell 4000 i connected a FW on the Advance DMZ... it is working but...
found out that Bell is giving a IP to the FW public interface of 70.27.x.x with a mask of 128.0.0.0

Also, Bell provide a nice D.G of 10.50.44.150... who is also under the 128.0.0.0 mask... For what reason would Bell use a /1 (not /24) Mask which take precedence over your internal IP's.

IF any of your FW interfaces is configured (example) with a 10.x.x.x IP... and your FW gets the D.G from Bell... it will tell you that there is a conflict !!!!!

10 IP Default Gateway outside... 10 IP Inside interface... Hello... where do i go. 

Think about it... 10.50.44.150/128.0.0.0 .... 10.50.44.150 / 1

anyone that are using 10.x.x.x IP inside (private) will be having problems... regardless of the submask they use...

[Vanadiel]

Your default gateway is not 10.x.x.x. Your default gateway is your modem's LAN IP which will be in the range of 192.168.x.x. for any LAN device. 

There's a separation between LAN 10.x.x.x and WAN 10.x.x.x addresses. 

[stvhull]

Vanadiel... i whish it was that easy... one thing i cannot argue with you is the fact that the private network of the Bell Router is in the 192.168.x.x as it is hard coded in it and you cannot change it... 

Here it is very important to understand that.. the Advance DMZ of the Bell Router is used... which mean that the Bell Router "kind of" share a Public routable IP (not Private CIDR) with a Security device like a FW... who also have its own private IP's .. and like my setup... multiple private IP ranges.... from which 1 was in the 10.x.x.x range.

Now... when the Bell Router share a public IP with my FW...... IP whIch will be assigned to my FW public interface (isp side) ... it also provide a DG... and here... Bell is providing an DG IP in the 10.x.x.x and tell my FW... here you go buddy... send all you traffic exiting your FW to this 10.x.x.x....

That is where the problem is... a security device (FW) will not send any NON-ROUTABLE traffic to a WAN interface unless it is instructed to... by the ISP... 

[Vanadiel · Accepted solution]

10.x.x.x addresses are reserved for private addressing, and are not routed in the global routing table and should be translated to global addresses with network address translation (NAT)

I use direct PPPOE connections without using a home hub, and my public IP address is the WAN address of my router, while the LAN IP of the router I use is the Default Gateway. I do not get assigned a Default gateway of 10.x.x.x

It should never assign a WAN address as a default gateway. Maybe you configured your firewall with a LAN address that is in the 10.x.x.x range?