Switching ISP modem router to bridge mode questions

[Charly]

Hi,
I have a Comcast modem (a Combo), which had an option to use the modem in bridge mode (just a simple switch.) I turned that on and waited, and it did the trick. Now, I need to make changes to the router. I have Linksys router (E4200). Inside the router, there is a 'release and renew' option for IPv4 and IPv6. Should I click on both?
My IP address still looks like a private one.
One thing I am concerned is if this is going to affect the connection to my Synology NAS server.
Also, I plan to replace the router in the next few days, and I understand I need to keep the IP addresses for all my devices, including the server, the same, to avoid any conflicts.
Just need to make sure that renewing the IP address for the modem is not going to affect the rest of my attached devices.
Sorry if this sounds very basic, but my NAS was installed by someone else, and my knowledge is limited.
Thank you!!

 

[thiggins]

When you switch a combo modem/router to bridge mode, it shuts off the router portion. That means the router you have connected to the combo now has to complete the connection with your ISP.
This means the router WAN settings must be set to the correct connection type. It is probably now set to DHCP. Try the release/renew and see if you get a proper public IP. If you don't, then you need a different connection type. There is probably a Comcast FAQ that will help you set your router properly.

Changing the WAN connection won't affect the LAN IP addresses. Those are controlled by the router. But if you change to a different router, all your LAN device IP addresses will probably change, even if the new router LAN IP address is the same as the old router's.

If each device is set to obtain its IP address automatically (via DHCP), all you should need to do is power down all devices, then bring them back up one by one, checking that each has internet connectivity.

 

[Charly]

When you switch a combo modem/router to bridge mode, it shuts off the router portion. That means the router you have connected to the combo now has to complete the connection with your ISP.
This means the router WAN settings must be set to the correct connection type. It is probably now set to DHCP. Try the release/renew and see if you get a proper public IP. If you don't, then you need a different connection type. There is probably a Comcast FAQ that will help you set your router properly.

Changing the WAN connection won't affect the LAN IP addresses. Those are controlled by the router. But if you change to a different router, all your LAN device IP addresses will probably change, even if the new router LAN IP address is the same as the old router's.

If each device is set to obtain its IP address automatically (via DHCP), all you should need to do is power down all devices, then bring them back up one by one, checking that each has internet connectivity.

Thank you Tim. This is very helpful!
So, about your last paragraph, will this apply to my NAS server as well? I remember that my friend set it to a fixed IP address. Will I be able to write the IP address listed in my server manually in the new router? Will that work?
Don't mean to bother anyone during the holidays with my questions , so we can continue this some other time.
Thanks again!

 

[coxhaus]

For devices like NAS servers you can set reservation in DHCP so it always gets the same IP address. Some people just set static IP addresses outside the DHCP scope so it would not change with a different router. Check the NAS's IP address settings and see if they are set to a static IP or DHCP. If set to DHCP it is using the router's DHCP and if set to just an IP address then the NAS is not using the router for an IP address. If it is set to DHCP then go into the new router and set a static IP address for the NAS's MAC address. It is fairly simple. Practice makes it simpler.

 

[Charly]

For devices like NAS servers you can set reservation in DHCP so it always gets the same IP address. Some people just set static IP addresses outside the DHCP scope so it would not change with a different router. Check the NAS's IP address settings and see if they are set to a static IP or DHCP. If set to DHCP it is using the router's DHCP and if set to just an IP address then the NAS is not using the router for an IP address. If it is set to DHCP then go into the new router and set a static IP address for the NAS's MAC address. It is fairly simple. Practice makes it simpler.

Many, many thanks for your explanation. This is very helpful.