ISDN router on wireless gateway WAN Port?

towbar

I'm using an SMC2804WBR wireless cable\dsl router. Does anybody know if it is possible to connect an ISDN router (Cisco 1603R) to the WAN port. I know its not how its designed and everything works fine by connecting the ISDN router to the ethernet ports but I would like to use the router as a gateway with uPNP.

The ISDN dial up connection is IOL anytime so dynamic IP address.

towbar

This doesn't look promising I guess, however I'll persevere and start thinking out loud!!!

I need to trick the router into thinking it has a DSL connection so I need to pick the DSL mode that has the least interaction as the 1603 will automatically setup the connection and manage the passwords etc. I could turn off NAT in the 1603 so the SMC router becomes the master gateway

The selections the router allows are

Cable Modem
Fixed IP xDSL
PPPoE xDSL
PFTP
BigPond


Anybody know anything about these as manual is sparse or is there anybody that has tried anything similiar with another router\gateway?

I have tried them all but may not have the correct settings.

ressem

Looking at the SMC PDF, it looks possible, though not neat.
What Ip details are given to your PC when connected directly to the router?

cmd
ipconfig /all

With NAT your SMC will be in one of the ranges
Class A 10.x.x.x
Class B 172.x.x.x
Class C 192.168.x.x
?

In which case there's a Static IP option in advanced setup/WAN, the gateway of the SMC would be set to the Cisco's internal address.
You'll have to manually set the DNS.

Alternatively if you want to turn off NAT, the
advanced setup/Wan/dynamic IP setting looks like a possibility, assuming the manual I'm looking at matches your firmware. Leave the MAC as the default.
based on
http://www.smc.com/drivers_downloads/library/SMC2804WBR_MN1.pdf

towbar

ressem,

Thanks for your reply. I have configured the smc to 192.168.1.251 it was on a 192.168.2.1. The cisco is on 192.168.1.250. I can view the wan status on the smc and with each config it said disconnected.

I tried static but hadnt thought about turning off NAT on teh router - that sounds like a good plan will try that and get back to you.

How would that work - the smc could figure out what ip the router had obtained if I turn off NAT - wont I always have to have an internal static IP on the cisco router?

maxheadroom

You might want to try "cable modem" mode on the router - it should just use standard ethernet for it (as opossed to PPPoE or PPPoA), given that your ISDN router is looking after all the authentication anyway..

ressem

Just ruling stuff out...
Haven't mentioned whether you can ping the smc from the cisco console? May need to switch off the smc firewall.
The smc is meant to autodetect mdi-mdix so it's unlikely that you need a crossed cable, ...

In NAT mode is the CISCO providing dhcp or are you statically setting the values on your PC/SMC whichever is directly connected?

Without NAT longshot.
Can you make the Cisco router act as a transparent bridge?

Really would like a console port on that smc...
maxheadroom's right though, cable modem should look the same as your cisco.

towbar

Folks,

Thnaks for feedback haven't had chance to try this. I think the major issue is that I hadn't turned off NAT on the cisco which would mean that SMC wouldn't be able to detect the IP address allocated by ISP but now I am confused again as ressem suggests that without NAT its a longshot??? Do you mean NAT on the cisco?

Cisco router isnt configured to provide dhcp and needs a remote tftp server to support this.

I am using cisco config maker to build the router config - its a 1603 R - dont see anything about making it a bridge but I think if I set it up with NAT turned off I might get there. The difficulty is that no matter what I do the cisco router will always have to have an internally allocated IP address 192.168.x.x which I suspect a cable modem wouldn't need to have.

It's going to look a bit like this

192.168.1.251 192.168.1.250 194.x.x.x
Int net < 192.168.1.x > SMC (with DHCP) <????> Cisco Router <-> ISDN to ISP
Gateway

For upnp and NAT to work on the smc the smc has to be aware of the ISP ip address but the router. I'll do a search for bridging on the 1603

I think the first step as ressem suggests is to get the router working locally on the PC and passing the isp address to the pc - this would be easier to debug.



Thanks again for the help, will post update over weekend,

maxheadroom

My cable modem has an external IP address in the 10.x.x.x range and an internal Ip address in the 192.168.x.x range. Set up your cisco to do nothing but access the net, and the smc to do all the routing and nat and stuff.

ressem

Never used config maker, just a serial port connection and ios.

Are you sure that you need a tftp server for DHCP?

Sorry if I'm insulting your knowledge but,

by console connection can you set the dhcp server using

en

# Type in
sh conf
# And save the results on your PC in case
# you want to undo the configurations.
# Or you can probably do this with your configmaker.

conf t
sh dhcpd
# will list the dhcpd settings currently enabled
#You should have
dhcpd lease 3600
dhcpd ping_timeout 750
dhcpd auto_config outside

# maybe
# ip address outside dhcp setroute
# or maybe not. BRI is a bit more messy
# than what I've got

dhcpd ?
# will list the available commands
# if you want to remove a line type it out and put
# the word 'no ' in front.

#Try
ip address inside 192.168.1.1 255.255.255.0
dhcpd address 192.168.1.2-192.168.1.33 inside
dhcpd enable inside


----
Try to see if this serves the address and gateway to your PC. If it works connect your SMC.
And set the SMC to enable VPN and set to cable modem mode.

By long shot I meant that I'm not sure that your cisco router can act in bridge mode.

I'm not a cisco trained pro so I might be missing something, just practice with the stuff I work beside.

Advice from boards resident CCNA's would be conforting.

towbar

ressem your right dhcp works fine on the cisco however not out of the woods yet.

Configured dhcp and tested on single PC everything worked as expected - automatically assigned correct IP and dns.
Connected to smc and it does negotitate the IP but still says cable modem is disconnected. Have tried both cable modem and dynamic IP (which appear to do the same thing)

The following is from the log on the smc
Receive Ack from 192.168.1.250, Lease time = 86400
Send Request, Request IP = 192.168.1.103
Get DNS Server IP[1] = 194.145.128.1
Get Gateway IP[0] = 192.168.1.250
Get WAN Subnet Mask = 255.255.255.0
Get WAN IP Address = 192.168.1.103
DHCP Client Lease Renewed

Also can see the request been processed on the console log for cisco

Tried with NAT on and off on the cisco router.


Although debugging is crap on smc - what should I be looking for on the cisco router - I presume I need to see if the smc even attempts to send any further packets after the address negotiation - for some reason smc still thinks it does not have a valid connection even though it negotiates the IP address correctly.


btw, no sign of any vpn options on the smc - why woudl i need vpn or how would it help?


I also tried to setup the static IP on smc to point to the cisco and it wouldn't allow me to use an address on the same subnet so moved smc back to subnet 192.168.2.x however static IP didnt work either and in fact when I set it up the cisco router started reporting duplicate IP address errors. I did though use the same IP address for the gateway setting?

ressem

I'd probably connect the 2 devices through a 4 port hub and use ethereal on your pc while connected to the hub to sniff the communications each way.

Seen all sorts of stuff on the web that suggests that the smc will only work with static mode, but can't verify.
Also reports that the smc doesn't like being changed from it's default ip/subnets. :dunno:

VPN was result of a brain crosswire. Meant NAT. Oops


Last gasp.
The smc log shows that the dhcp was transferred but are the changes reflected on the smc configuration pages?

Ignoring the web interface saying not connected,
Can you ping the cisco from the PC behind the smc?
After that I fall into the usual crap, upgrade smc firmware, reboot, reset SMC to default subnet config and adjust cisco and pc to suit.


I'm pretty much out of ideas unless I break rules and drag my home smc into work.

Given that this is a wired networking qn might be worth asking the mod to move this to Net/Comms for more eyeballs.

towbar

ressem,

hope your not going to send me a bill for all this!!!

thanks again.


Good idea on the sniffing haven't used ethereal before but will try it. Its pound to be easier than parsing packets on the cisco router.


The smc config pages dont show the wan configuration at least not anywhere than I can find it. It just says dynamic ip. Is there anywhere that I can see what values smc has assigned to the wan interface?

Does the output to sylog server provide extra logging or just the basic as it appears in the console window


I'll try changing back to default subnet - who knows.

Don't break the rules - if you think you might see something could setup a temporary remote console but pretty much have been through all the screens.

towbar

Folks,

Thanks for the help - I upgraded the firmware on the smc and started from scratch and now can use the WAN port although smc still reports wan port as disconnected.

I still have to get my head around how I am going to get upnp to work as the smc wireless router still does not know the allocated IP address however thats another days work. In the meantime I appear to have a doubly secure network with NAT on both devices!!


Towbar