DHCP/DNS servers on IP other than x.x.x.1



  • Simple questions this time. I have a LAN subnet x.x.5.0/23. This sets the DHCP and DNS servers at 5.1 with a useable IP range of 4.1-5.254. Using Proxy Arp VIP and 1:1 Nat. Have primary lease pool from 4.1-4.254 & 2nd pool from 5.2-5.62. I would rather start the 2nd pool at 5.1 otherwise I loose a public IP. Is there a way to have the servers on something other than 5.1, say 5.254 perhaps? Could this create a problem with other router functions?


  • Banned

    And where exactly did you find this requirement that DHCP/DNS servers must run on IP like x.x.x.1?  ??? :o


  • LAYER 8 Global Moderator

    Huh? Not a clue to where you heard any such thing about .1 ??  Can tell for sure I run pfsense on .253 because soho devices normally have .1 or .254 so I never try and put anything on those address no matter my network.

    I have dns running on box with a .10 address as well.. etc. etc. There is no rule or best practice about any specific IP.  Its just common that .1 when you bring up a router you normally use the first or last address on network.. But there is nothing saying that has to be done.



  • This sets the DHCP and DNS servers at 5.1

    While consumer router/NAT/firewall/DHCP server boxes are commonly on .1, there should be a setting somewhere that you can change from that default.



  • It's just an adopted convention that everyone seems to take as a "standard". There's nothing in the TCP/IP networking itself that requires you to use a specific addresses from subnet for DNS and/or default gateway or any other function such as NTP or NIS server addresses. You could for example use 192.168.1.128 as the default gateway out of 192.168.1.0/24 and it wouldn't be any different than using the usual 192.168.1.1.


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