Cisco 1700 Series router and 4 fixed WAN IP addresses

Posted on 2010-11-17
Last Modified: 2012-05-10
I have a Leased line with a Cisco 1700 series router on it.
I do not have the access to it as it has been provided by the ISP.
All I have been given is the IP range information for it.

For example puposes:

Range given is :

This gives me a wan ip of  *.233 and 4 fixed IPs at .234 .235 .236 .237
Then one Netgear FVS318 attached to this which had a WAN IP of .234 asssigned to the WAN port and Gatway of .233.

The internal/LAN range being 10.0.0.x

But I wanted to use an additional WAN IP so....

Being new to using this I just added a switch between the single port on the Cisco 1700 and the Netgear FVS318. Still worked fine. Then added another FVS318 to the switch and gave it a WAN IP of .235 and Gateway of .233.

That all worked fine with no problems as far as I can see.
Also added a PC to the switch and gave it an IP of .236 and that works fine too ( just as a test )

But... I attached a SonicWall TZ210 in much the same manner giving it's WAN interface an IP of .237. However as soon as the device is attached everything else loses it's network connectivity.  The only way to get it back is disconnect the WAN port of the TZ210 from the switch ( switch conected to Cisco 1700/Leased line ).  Then power off the other routers and back on.

So the SonicWall TZ210 just kills everything else.

Any ideas??

Question by:JohnSchneider
  • 4
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Expert Comment

ID: 34158318
did you plug in to uplink port?? some switch share port 1(or last one) and uplink  you can't use them together.  the uplink port is kind of seperate from the rest and there should be a straight line between uplink port and the port next to it.

Author Comment

ID: 34159783

It is a 16 port unmanaged switch.
Cisco is for example plugged into a random port like port 5.
The other devices have their WAN port plugged into any other switch port.

I guess what I am asking is:

A: Is this a good way of doing it.
B: Is there an issue with TZ210 that is preventing it from being installed in this manner.


Expert Comment

ID: 34160240
A: you can use TZ210 connect to 1700 and set TZ210 to NAT to different external IP.

B: double check your TZ config. make sure IPaddress is correct.

Author Comment

ID: 34160330
Can the TZ210 be used to have all 4 Fixed Ip's on one WAN interface?

Something like IP Alias Address Mapping. Then use NAT/Firewall rules to direct the incoming trafffic to the appropraite internal Lan Devices.  I have multiple use of ports like 80 etc and thats why I need those fixed IP's tramslated to various different internal IP's.

Then do away with the Netgears?
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Expert Comment

ID: 34160400
I don't have experience with TZ. . this device is able to do it.but look at NAT policy

Accepted Solution

ajeab earned 500 total points
ID: 34160408
you can forget about netgear.  you can forward external IP , translated to internal IP

Author Comment

ID: 34160440
OK I think you are right in that that TZ should connect to the 1700.

Then I believe - looking at another posting - that I attach the first WAN IP to the WAN port on the router.
I then run the Wizard/Public.  Create a NAT entry for the internal IP and when it asks if I want to use the default WAN address I have the option to choose another one.

Thus creating NAT entries for all the internal servers I need and just match the Internal server to relevant External IP it needs.  The wizard will create all the objects needed in the right places and make the links required so that all the 4 external IPs can be used up using the single wired WAN interface.

Well i will see tomorrow and let you know.  Although to test this I now have to take the internet offline so it can only be done when it is quiet enough....
LVL 33

Expert Comment

ID: 34161800
how you have it configured should work fine.  you might need to configure the WAN interface of the sonicwall from auto duplex and auto speed to something like full duplex/100mb or something.  you may have to play around with the settings there.  confirm your gateway and IP are correct on the sonicwall.  incorrect settings can cause issues with the routing tables of the other hardware.  restarting them would clear this.  there's nothing on the sonicwall that should prevent it from connecting properly.

Author Closing Comment

ID: 34201798
It was easier to ditch the Netgears and put all 4 Wan IP's through the one SonicWall physical WAN port.  The wizard on the SonicWall OS actually made it a breeze to do.

The Sonicwall SSL VPN attached worked first time too.

So I will go with the "forget the netgear" answer... thanks to all.

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