Cisco 678 DSL modem/router options, & 2nd router configuration questions.

I have a Cisco 678 DSL modem/router with the options set as PPP enabled, NAT enabled, & DHCP enabled. (Default Gateway IP is 10.0.0.1) The LAN side wired to a 2nd standalone router (eHome, md # eh100) with "4 wired ports & wireless" capability. That 2nd router's Internet Connection is configured as a "Static IP" and is given the IP address of 10.0.0.2 from the Cisco modem/router. The 2nd router also has DHCP enabled and reports the default gateway IP address is 10.10.10.1 and than provides IP address of 10.10.10.100 ect to my 2 other standalone computers.

Question 1. Do I set my MTU at 1492 or 1500 on the "eHome" router since the Cisco modem/router is set for PPP & uses some of the overhead for logon purposes?

Question 2. Can I set my 2nd router's Internet connection to "Dynamic IP (DHCP)" and turn off its DHCP Server options and have the Cisco modem/router provide all the necerary IP address?

Question 2a... If that works, will I be able to run IPCONFIG/ALL and see all the equipment back to & including the Cisco 678 modem/router? As it is now I can't see past the "eHome" router. Would I need to change the "ehome" router into a AP ,Hub or Switch to see all?

Question 3. Am I gaining anything by having two routers set to DHCP?

Question 4. As it set up now, do I have two hardware firewalls & one software firewall (ZoneAlarm) & is the redundancy slowing me down?

Side note.. the system, as it is currently configured is rock solid for over a year now... the questions stem from boredom due to lack of tinkering with it...

thanks in advance for any input..
denny

 

Q2:yes you can, it makes thing simple.

 

It appears to me that the eHome router is simply being used as a switch and wireless access point - that is the only thing it is added to your network is extra ports and wireless.

I'd recommend you switch off DHCP on the Cisco router, and make sure the Cisco router and all the wired PCs connect to the internal ports on the eHome router. Do not connect the Cisco router to the external/WAN port on the eHome router. It should then just work.

The command to trace a route is tracert and not ipconfig. ipconfig tells you the configuration of the device it is run on.

 

Thanks Jason and ReggieB for your response's.. and yes ReggieB your interpretation of my setup is correct. But I don't think I can turn off the DHCP on the Cisco 678.

The Cisco 678 modem /router does not have a http graphic interface that I know of. It's configured vie a serial cable and a comm program like Hyper Terminal, and tech support other than initial setup is next to non existence. I'll dig though my notes and see if I can find the input commands for optioning the 678.

I'll try what Jason's suggested this weekend. I wasn't sure if changing the ehome router's internet connection from static to dynamic and turning off the "DHCP" server setting would allow the Cisco "DHCP " "LAN" side to assign address vie the ehome wan port than out the lan ports to each of my computers.

Anybody have any thoughts about questions 3 & 4? I would like to justify my need to tinker...

thanks again..

 

You definitely can turn off the DHCP service on the Cisco router, but if you don't have any management tools, you'll will have to do it in IOS which can be daunting.

The reason I suggested using DHCP on the eHome was to ensure the DHCP packets were passed onto the wireless clients. I have seen examples of wireless devices not passing DHCP from the wired network on to the wireless network. However, the main thing is that you only have one DHCP running. So try turning DHCP off on the eHome router instead - it probably will work that way.