Externally provided DNS Server address of .255 out of range

[chris.hughes]

We have a Cisco RV042G Gigabit Dual WAN VPN Router.

We need to use an external DNS server provided by Gamma that has an IP address with the last value being .255   (i.e 88.*.*.255)      

However, the Router comes back with an error message :

"DNS Server last value is out of range (0-254)"

I know you cant use .255 internally, but as Gamma have many customers using their public DNS server of .255,  what could be the problem here?

Many thanks          

[chris.hughes]

Anyone?  :- )

[John Blakley]

Looks like the value is hardcoded to .254 as the last octet. Can you use a different dns provider like 4.2.2.1, 4.2.2.2 or 8.8.4.4 and 8.8.8.8?

HTH,
John

*** Please rate all useful posts ***

[chris.hughes]

Yep, currently connect to 8.8.8.8, but of course, they could change their IP at a moments notice, being who they are  ;-)  ....

[daniel.dib]

Looks like the code didn't count on 255 being able to be used. It's perfectly valid host address depending on mask.

Interestingly you are allowed to enter 0 which it would make sense if you couldn't if .255 was restricted.

Maybe you could open a case or ask for a feature request if such things are possible for this platform.

Daniel Dib
CCIE #37149

Please rate helpful posts.

[chris.hughes]

Thanks Daniel. Looks like it is a "feature" of this router then ;-)

Think a different router is required meanwhile.