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Is it possible to assign the same static IP for two different MAC addresses?

Scheduled Pinned Locked Moved DHCP and DNS
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  • D
    Derelict LAYER 8 Netgate
    last edited by Sep 8, 2014, 9:00 PM

    Or just get good wireless and stay on it even when docked.

    Chattanooga, Tennessee, USA
    A comprehensive network diagram is worth 10,000 words and 15 conference calls.
    DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
    Do Not Chat For Help! NO_WAN_EGRESS(TM)

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    • J
      johnpoz LAYER 8 Global Moderator
      last edited by Sep 8, 2014, 10:08 PM

      "Or just get good wireless and stay on it even when docked."

      Exactly – here is the thing if your going to be changing networks, you have to expect that a session would die, just reconnect - I don't see an issue here at all.  if I had a ssh session open and I went from wired to wireless - then yeah that session would have to be reopened.  What is the saying you can't fix stupid ;)  Anyone that would think they can maintain sessions while changing their connection type doesn't understand networking ;)

      Even if you move your IP to a different nic - your session like ssh is still going to die..

      So your complaint is your ssh client doesn't reconnect for you?

      As stated to solve your problem don't move your connection - use wireless while docked or undocked, there you go problem solved you never loose your connection ;)

      An intelligent man is sometimes forced to be drunk to spend time with his fools
      If you get confused: Listen to the Music Play
      Please don't Chat/PM me for help, unless mod related
      SG-4860 24.11 | Lab VMs 2.8, 24.11

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      • K
        kejianshi
        last edited by Sep 8, 2014, 10:15 PM

        Unless your wireless drops…  Which never happens (-;

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        • D
          Derelict LAYER 8 Netgate
          last edited by Sep 8, 2014, 10:29 PM

          Which is why I said good wireless, not some $19 tp-link from walmart.

          Chattanooga, Tennessee, USA
          A comprehensive network diagram is worth 10,000 words and 15 conference calls.
          DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
          Do Not Chat For Help! NO_WAN_EGRESS(TM)

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          • S
            stpq
            last edited by Sep 9, 2014, 8:04 AM

            "Even if you move your IP to a different nic - your session like ssh is still going to die.."
            ehm, nope..

            "So your complaint is your ssh client doesn't reconnect for you?"
            yeah, but do u have any clue how long it takes for ssh to timeout?

            wireless…. hmm... something like AC than, and even that wont give u gigabit... wire is wire and wireless sux, regardless the price of it..

            And again, dont take me wrong, as i stated earlier... I  just think, that it can be a valid argument... I mean its implementen in ISC.. its a feature, not a liability...

            s

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            • D
              Derelict LAYER 8 Netgate
              last edited by Sep 9, 2014, 8:20 AM

              So you want:

              1: the speed of Gig-E when you're wired
              2: the convenience of wireless when you're not
              3: total disregard for the OSI model when you switch between them.

              Got it.

              Chattanooga, Tennessee, USA
              A comprehensive network diagram is worth 10,000 words and 15 conference calls.
              DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
              Do Not Chat For Help! NO_WAN_EGRESS(TM)

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              • K
                kejianshi
                last edited by Sep 9, 2014, 9:32 AM

                I'm convinced personally - I'm switching all my servers to wifi (-;

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                • S
                  stpq
                  last edited by Sep 9, 2014, 10:06 AM Sep 9, 2014, 9:53 AM

                  @Derelict:

                  So you want:

                  1: the speed of Gig-E when you're wired
                  2: the convenience of wireless when you're not
                  3: total disregard for the OSI model when you switch between them.

                  Got it.

                  you are totally right…

                  but look at this: https://forum.pfsense.org/index.php/topic,36066.msg186013.html#msg186013

                  so it still might be possible...

                  and does it violate OSI model to have two interfaces with addresses from the same subnet?

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                  • D
                    Derelict LAYER 8 Netgate
                    last edited by Sep 9, 2014, 5:16 PM

                    No.  It violates the OSI model having two interfaces with the same MAC or two MACs with the same IP.

                    Chattanooga, Tennessee, USA
                    A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                    DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                    Do Not Chat For Help! NO_WAN_EGRESS(TM)

                    1 Reply Last reply Reply Quote 0
                    • D
                      Derelict LAYER 8 Netgate
                      last edited by Sep 9, 2014, 5:26 PM

                      @stpq:

                      and does it violate OSI model to have two interfaces with addresses from the same subnet?

                      You have two interfaces:  eth0 at 192.168.1.13 and eth1 at 192.168.1.14

                      Your default gateway is 192.168.1.1

                      Which interface(s) should be used to send traffic to the gateway?

                      It's not against the model, but requires special consideration and per-interface (not just per-subnet) routing rules.

                      Chattanooga, Tennessee, USA
                      A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                      DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                      Do Not Chat For Help! NO_WAN_EGRESS(TM)

                      1 Reply Last reply Reply Quote 0
                      • J
                        johnpoz LAYER 8 Global Moderator
                        last edited by Sep 9, 2014, 5:54 PM

                        @stpq:

                        "So your complaint is your ssh client doesn't reconnect for you?"
                        yeah, but do u have any clue how long it takes for ssh to timeout?

                        Would depend on the settings in ssh server.  What are the settings for ClientAliveInterval, TCPKeepAlive and ClientAliveCountMax?  They could be very short, or very long depending on what the admin of the ssh server set.

                        Where is this a ISC dhcp feature - just because you can get something to load and function in the config, does not mean its a SMART thing to do ;)  You can do lots of things that some software will allow - doesn't mean its good practice ;)

                        Networking 101, mac's are suppose to be unique.  You wouldn't want the same IP address on different macs..

                        An intelligent man is sometimes forced to be drunk to spend time with his fools
                        If you get confused: Listen to the Music Play
                        Please don't Chat/PM me for help, unless mod related
                        SG-4860 24.11 | Lab VMs 2.8, 24.11

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                        • C
                          Cino
                          last edited by Sep 10, 2014, 9:53 AM

                          I agree with what everyone is saying but there is a way to assign the same static IP to two different MACs. I do it if I assign a static IP to a device that has multiple interfaces (WDTV, Roku 3, TVs, Work Laptop)

                          This is not supported by pfsense and could break your system if you mess up!!! I hold no responsible if you break your system nor do I offer support. But I am willing to share the knowledge of how it can be done

                          You will have have to manually edit your config.xml… Goto you the <dhcpd>section then look for <staticmap>... You should get the idea of how to do this...Once you save your changes, reboot your box..

                          
                          			 <staticmap><mac>00:19:9d:12:9f:4c</mac>
                          				<ipaddr>192.168.0.51</ipaddr>
                          				<hostname>vizio</hostname>
                          
                          				 <filename><rootpath></rootpath></filename></staticmap> 
                          			 <staticmap><mac>00:19:9d:08:dc:05</mac>
                          				<ipaddr>192.168.0.51</ipaddr>
                          				<hostname>vizio</hostname></staticmap> 
                          
                          

                          Capture.JPG
                          Capture.JPG_thumb</staticmap></dhcpd>

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