Setting up router and sonicwall in routing mode

I have an issue on a site with bridge mode so need to change to routing mode. The router works perfect on its own but when put into bridge mode with a SonicWALL there are drops every few minutes. I  want to change the setup to routing mode so both the router and firewall will both have internet IP's

Lets say ISP supplied IP's are

I configure my router to a dynamic IP which means I should get the 208 address
I turn off DHCP, Firewall and NAT and set the Lan interface of the router also as the 208
I then configure my firewall to be 209 on the Wan interface with a gateway address of 208. I connect a cable from the WAN port of the SonicWALL to the lan port of the router
I should now be able to access the internet via the Lan side of the firewall..

Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Hemil AquinoNetwork EngineerCommented:
Your statement it's kind of confusing to me.

Question #1: Do you have two static IP address or only one usable IP address?
Question #2: Which one is connected to the internet now? the firewall or the router?
Question #3 why do you need a router an firewall? any option specifically?
Steve McCarthy, MCSE, MCSA, MCP x8, Network+, i-Net+, A+, CIWA, CCNA, FDLE FCIC, HIPAA Security OfficerIT Consultant, Network Engineer, Windows Network Administrator, VMware AdministratorCommented:
My recommendation is to fix the problem, not put a work around in place.  Issues I have seen with this exact thing are that the modem is not actually in bridge mode or there is a problem with the ISP.  For example, Xfinity modems have a setting for Bridge mode and you would think that it is all you have to change, however what is not well known is that you must call them to put you into Bridge mode. Yes that one setting is essential, but there is also another setting that only they can access.

At a client I am working on now, they got a Static IP from Xfinity, but it would never work when we put it in the SonicWALL.  Turns out that the ISP had not configured their side properly.  If they are setup properly, then that SonicWALL should work just as designed and you should be able to statically put that .208 address in the configuration for the WAN port with the appropriate subnet mask and gateway, also with entering the ISP's DNS Servers.

BTW in either mode, router or bridge, that modem connections should be going into that SonicWALL's WAN port. That Public IP address has no business on your Routers LAN port. In true Bridge mode, that router is transparent to your network. The WAN interface on the firewall holds everything and you don't have a thing to do with the router.  When the modem/router is in Routing mode, it does the NAT and gives you SonicWALL WAN interface a DHCP address. On Xfinity it is in the 10.x range.

So, ideally, your ISP Modem/Router should be in Bridge mode, being transparent to your network.  Your SonicWALL should have the .208 address configured statically with the other settings the ISP gives you. Out of that SonicWALL on the Lan ports should be your internal subnet.
Which ISP do you have, and I am assuming that they provided 2 statics?
Sid_FAuthor Commented:
Two settings were changed to bring stability 1) MTU size lowered 2) Fix/Ignore malformed TCP headers enabled check box. Although we stayed with bridge mode I find it a pain and have always preferred routing mode.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Sid_FAuthor Commented:
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.