G+_Dan Hockey Posted June 9, 2017 Share Posted June 9, 2017 I have a centurylink C1100Z modem/router and a synology RT1900ac router. I've been trying to bridge to the synology so I can have it handle the port forwarding and maybe vpn. The last time I tried my network went from 192.168.x.x to 10.10.x.x, that made all my toys that used a static ip's very unhappy and refused to talk me at all. Since everything changed I could no longer log in to the C1100Z to change the settings back to where they were. The only way to get the internet back is to do a factory reset on the modem which cause's me to have century link to re-bless my modem before it will work again. Everything I've googled for says bridging should work, but not for me. I haven't tried to use DMZ yet but from what I've read so far it seems to me that DMZ does almost the same thing as bridging. Is there something that I'm missing that's causing bridging not to work ? What IS the difference between DMZ and bridging? Link to comment Share on other sites More sharing options...
G+_Black Merc Posted June 9, 2017 Share Posted June 9, 2017 What was the steps you used before the disaster? I experienced a similar mess when the dhcp supplied address on my routers WAN port changed from a 10.x.x.x to 192.168.x.x . My router paniced and changed the lan from 192.168.x.x to 10.x.x.x . Which did exactly the same effect. Apparently you cannot have the same ip range on both sides of a router. Link to comment Share on other sites More sharing options...
G+_Travis Hershberger Posted June 9, 2017 Share Posted June 9, 2017 Black Merc?. Yes, you can not route between the same subnet on two sides of a switch. Link to comment Share on other sites More sharing options...
G+_Ben Reese Posted June 9, 2017 Share Posted June 9, 2017 With my experience, bridging a Century Link router/modem gives the public IP to the WAN port of the second router. This is different from double-NAT in which the modem/router keeps the public IP and gives the second router an internal IP (in the 192... Or 10... range). I suspect what you'll want to do is disconnect from the Century Link network and connect to the second router to configure it how you want it (set it up to use 192... network instead it's default 10.... network). Also make sure DHCP is turned on since you're CenturyLink box will soon stop supplying that service. Once that router is ready, connect your computer to a LAN port of CenturyLink and switch it to bridge mode. Disconnect EVERYTHING from CenturyLink except for your second router. This will be the new connection for everything. As a note, you should always be able to get back to the bridge/router configuration of CenturyLink on 192.168.100.1 - assuming you aren't using that subnet for your main home network. As for the difference between DMZ and bridging, DMZ acts as a mass port forward. Everything without an explicit forward destination will get forwarded to the DMZ internal IP. NAT still applies with DMZ. Bridging passes all the traffic through to the connected device, but NAT shouldn't happen with bridging. There's no opportunity (that I know of) for another device to connect to the CenturyLink network. Link to comment Share on other sites More sharing options...
G+_Dan Hockey Posted June 10, 2017 Author Share Posted June 10, 2017 My current setup is... #1 lan port on the C1100Z goes to the wan port on the synology. WiFI and anything else I don't use is turned off. On the synology, it shows 3 options for the internet connection.... 1. Auto 2. PPPoE and 3. Manual. Currently it is set for Auto and DHCP is enabled. So if I understand this right, disconnect the syology from the C1100Z, connect a computer, turn on bridging, disconnect computer then reconnect #1 lan port to the wan on the synology. If the sun, moon, and stars are aliened correctly it should work? Link to comment Share on other sites More sharing options...
G+_Black Merc Posted June 10, 2017 Share Posted June 10, 2017 I'd rather utilize as much of the C1100Z capabilities as much as possible for security reasons. If it gets 'owned', you still have the security of the synology. Link to comment Share on other sites More sharing options...
G+_Ben Reese Posted June 10, 2017 Share Posted June 10, 2017 Dan Hockey yup, that's pretty much it. Technically you could do all the C1100Z configuration from connected to the Synology router, but since you want Synology to use the subnet range that the C1100Z is using, that could cause complications. Link to comment Share on other sites More sharing options...
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