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ralfwolf's profile

New Contributor

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7 Messages

Sun, Apr 19, 2020 3:00 PM

Can't add 1:1 NAT entry

I am unable to add a 1 to 1 nat entry.  I have an existing one that is working but when I try to add another one in the same way, it gives me an error "Failed, please try again later.
Message: Failed to add".  I have a /29 static subnet and I'm specifying an IP address within that range.  My internal IP is in the routers standard 10.1.10.0/24 subnet.  Neither the internal nor external address is used by my exising nat entry.  I have tried resetting my router.

Official Employee

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521 Messages

2年前

Thanks so much for taking the time to reach out to us regarding your 1:1 Nat concerns. I very much appreciate your patience and greatly apologize for the delay in our response. I know how important the services are to your business and we want to do all that we can to assist. Can you please reach out through private message with your first and last name, business service address and account number or phone number?

New Contributor

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10 Messages

2年前

Did you ever get an answer to this?  We tried to "change" one entry and "Failed Please try again later"  Don't delete and entries, you will never get them back.

Problem solver

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348 Messages

2年前

Hi there, thank you so much for your feedback on what steps you took to resolve the issue and we do appreciate your time. Is there anything else that we can do for you or do you have any other questions or concerns regarding your account? 

New Contributor

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7 Messages

2年前

No, I ended up figuring out myself that I was able to turn off  nat completely on the comcast router so at least it wasn't interfering and reconfigured to using the "true static ip" feature.  Basically if you have another router or devices directly connected to the comcast gateway, then you can use your static ip directly with the gateway set to the gateway of your static IP subnet which is the first IP in the full netmasked range.  I ended up getting a ubiquity ER4 which allows me to use all of my static IPs and control all NAT entries in much more flexible ways than the comcast router allowed.

 

New Contributor

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10 Messages

2年前

There is a way to add/change your 1:1 NAT Table.  The source of the problem is the DHCP server addresses controlled by the routers DHCP.  All of the LAN IP addresses must be in the range of DHCP addresses controlled by the router. STUPID, yes but after you setup the NAT table you can then correct the DHCP address limits. 

For example our fixed addresses are in the 192.168.1.2 thru 192.168.1.32 range.  192.168.1.1 is the router itself.  I must set the router's lower DHCP address to (in my case) 192.168.1.2 in order the edit the NAT table without getting the FAILED error.

 

After the editing the NAT is done I set the lower limit back to 192.169.1.32 and reboot.

 

Works great.

 

Fred

New Contributor

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3 Messages

@TheTroupe

Your answer IS the solution to this bug in the Comcast Business router.  Your answer worked for us also.

I have a block of 5 Public IPs from Comcast Business, so defining many NATs and PATs must be done for our medium sized business with a rack of servers using Static IP Addresses on the 10.1.0.x Subnet.

When I talked to Comcast Business Support on March 22nd, 2022 they admitted that your solution IS the work around to their buggy Comcast Business Router firmware that has not been fixed in years. It is just CRAZY that a business customer has to make their DHCP Pool range overlap their Static IP Address range just to create new NAT and PAT Router entries.  This is NOT a Business level offering for Comcast Business customers that are in the Small to Medium sized business range.

I bet the Comcast Business Enterprise customers get a real Cisco Router from Comcast for their service.

(edited)

New Contributor

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10 Messages

@MediumSizedCustomer​ WARNING!!!  This fix no longer works when Comcast updates the router.

You will have to enter "reserved" ip addresses instead.

F

New Contributor

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3 Messages

@TheTroupe​ Can you elaborate on this "reserved" ip address method?

I just received a new Comcast CGA4131COM Business router (CBR-T) on March 18th, 2022 and your DHCP temporary change is working fine to allow for the creation of many NAT and PAT entries.

New Contributor

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1 Message

1年前

Your are awesome!

I got on here just to tell you that.

This answer worked great for us!

New Contributor

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1 Message

1年前

Thank you Troupe, that was my problem- I had the DHCP set to assign IP's from x.x.x.50+ and was trying to set NAT to x.x.x.3 & x.x.x.9 - they should update the error code to tell you that the Private IP is not within range of the DHCP server. It would have saved me 2 hours on the phone with tech support who couldn't figure out the problem.

(edited)

New Contributor

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10 Messages

3分前

WARNING!!!  This fix no longer works when Comcast updates the router.

You will have to enter "reserved" ip addresses instead.