bridge mode


I have a small ISP setup. This is currently on WiFi 802.11b devices. I want to migrate to Motorola canopy system. With this system I hope to expand my already running ISP. Currently my user base is of just home users (roughly 100) on private IP.

Following is what I want to do:

ISP—>Gateway 1 & 2----->AP &CMM----->SM----->Switch----->user 1,2,3,4

User 1 is on private IP say 172.16.x.x
User 2 is on a private IP in the same range i.e. 172.16.x.x
These both connect to gateway 1

User 3 is on a public IP say 203.193.x.x
User 4 is on a public IP say 202.54.x.x
They connect to my gateway 2

I have to have 2 different gateways due to some other reasons. Gateway 1 is for private IP users. Gateway 2 is for public IP users.

My questions are as follows:
1) Can my AP and SM work in bridge mode with NAT to allow different IPs to flow through them?
2) If not this particular mode, which other way can I make this work? What will be my considerations for the same?
3) Does this work with only a particular type of Canopy product or all of them?
4) Can I use various SMs with the same AP cluster/CMM where particular SM is dedicated for 1 public IP user and the other one is for a number of private IP users on the same AP cluster/CMM?

I really need help on this one. Anyone who can answer me this one gets a free beer ?


APs, SMs, and BHs are all, by default, self-learning bridges; they’re Ethernet switches. The CMM, to the IP networks, is also just an Ethernet switch. You can combine as many different IP networks and gateways as you want. The Canopy units themselves will also each be assigned an IP address; Motorola suggests these addresses always be private because of a problem with the units’ web server.

NAT is available in the SMs; it’s turned off by default. There are two limitations, if I’m reading your post correctly, that may affect you:

1. Don’t assign a public IP address to the SM and then NAT to private addresses for the customer’s PCs.

2. You likely cannot have both public and private addresses behind a single SM if the SM is doing NAT. I’ve never tested this but, like any router, it should not work.

Teknix wrote:

2. You likely cannot have both public and private addresses behind a single SM if the SM is doing NAT. I've never tested this but, like any router, it should not work.

You might be able to do this if you put a sophisticated router in the DMZ of the SM which is in NAT mode. Then used a tunnel to another router on the outside to tunnel a subnet of say public IP addresses through the private tunnel or visa versa. Its possible, but probably more work and less stability than to just place 2 SM's at one location. :D

montievv wrote:

Following is what I want to do:

ISP--->Gateway 1 & 2----->AP &CMM----->SM----->Switch----->user 1,2,3,4

We have a similar setup in many locations on our network. Usually this is done for office complexes where many different offices need a public address for their servers. We have our cisco 7200 router configured to accept both a set of 192.168.x.x private addresses and 207.x.x.x public addresses on the same lan and route them out to the internet.

We place the SM in non-NAT mode and allow it to pass all traffic (except network neighborhood, bootp, ipv4 multicast which is blocked in the SM services page). Each customer has to buy a router and the router has in its WAN interface placed either their private address or public address. Just as a heads up we have found that linksys routers consistantly end up with corrupted arp or routing tables and need to be rebooted after a few days of operation when they are placed behind an SM.

If you wish for a customer to have more than 1 private or public IP address that can also be accomplished. It would just require your customer to use a router that can route WAN subnets instead of routing single addresses only (like the standard off the shelf router).