What subnet mask has been entered for this static IP address? (255.255.255.254)?
Typically the gateway address is in the same subnet as the static IP address.
A /31 IP address allows for only two hosts in the subnet. (device and gateway)..It had never occured to me to wonder how ISP's would assign static IP's. This implies that for every static IP they assign, they burn another IP address from their pool for the gateway.
Hi, Thanks for answering. Yes the settings are as follows:
IP: xxx.yyy.zzz.67 Subnet Mask: 255.255.255.254 (as foreseen in the point/point connections following RFC 3021 specificatiins - https://tools.ietf.org/html/rfc3021) Gateway: xxx.yyy.zzz.66 DNS Primario: 8.8.8.8 DNS Secondario: 1.1.1.1
the ISP said that if the router doesn't support the RFC 3021 they can provide a /30 class IP at an additional monthly fee. eheheh.
What a deal (not). Actually, I believe the advice was to cheat. Put in the static IP and the gateway IP and then use a /30 subnet mask instead of a /31 mask. Any broadcasts generated by the router would just 'disappear'
Several internet searches have turned up similar questions for other Netgear routers, but no definite answers.
The invalid IP message was indeed because of the subnet mask .254
I then tried to put .252 but I got the message "Invalid Subnet mask" (???).
The only way fwd was to put .248 and everything went fine. Still unclear to me how come a good device like the Orbi RBR20 has these kind of issues while when putting all the parameters with /31 subnet in my 20 euro wifi router everything worked smoothly at first attempt...
The invalid IP message was indeed because of the subnet mask .254
I then tried to put .252 but I got the message "Invalid Subnet mask" (???).
The only way fwd was to put .248 and everything went fine.
Truly disappointing. Since subnet masks must be "all 1's starting on the left and then all zeros", the only valid subnet masks are 128. 192, 224, 240, 248, 252, and 254. which correspond to /24, /25, /26, /27, /28, /29, /30, /31
II wonder how common it is to use a pair of IP's to define Static IP's? A Class C address, for example, would support about 252 customers (reserving 0, 255 for broadcast, one for the gateway) but only 126 customers using two IP's for each.
The "point to point" method may be more secure. Even if one customer cheats and uses a wider subnet mask, none of the other customers will respond to him because they are limited to the single connection.
p.s. I have sent private messages to two forum moderators asking for comment and not heard back from either.
