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![]() ![]() For example, if a group of hosts are powered off at night, This increases the stability ofĪddresses. Hosts with a previously recorded address SHOULD use that address as Interface, record the IPv4 address they have selected. ![]() Hosts that are equipped with persistent storage MAY, for each Pseudo-random sequence, conflicting on every address they probe. Using the real-time clock or any other information which is (or mayīe) identical in every host is NOT suitable for this purpose, becauseĪ group of hosts that are all powered on at the same time might thenĪll generate the same sequence, resulting in a never- ending series ofĬonflicts as the hosts move in lock-step through exactly the same Seeding the pseudo-random number generator ![]() Storage, a host will usually select the same IPv4 Link-Local addressĮach time it is booted, which can be convenient for debugging and This means that even without using any other persistent Generator SHOULD be seeded using a value derived from this Host, such as its IEEE 802 MAC address, then the pseudo-random number Host has access to persistent information that is different for each The pseudo-random number generation algorithm MUST be chosen so thatĭifferent hosts do not generate the same sequence of numbers. ![]() The first 256 and last 256 addresses in the 169.254/16 prefixĪre reserved for future use and MUST NOT be selected by a host using The IPv4 prefix 169.254/16 is registered with the IANA for this When a host wishes to configure an IPv4 Link-Local address, it selectsĪn address using a pseudo-random number generator with a uniformĭistribution in the range from 169.254.1.0 to 169.254.254.255 See RFC 3927, Dynamic Configuration of IPv4 Link-Local Addresses: IPv4 link-local addresses are randomly chosen by a device, then a check is performed to see if another device on the LAN has the same address (Duplicate Address Detection). There are also some other, proprietary protocols around but LLDP and CDP are more common. You could try to listen to LLDP (Link-Layer Discovery Protocol) or CDP (Cisco Discovery Protocol) frames, advertising the switch and its IP address on its ports (when activated). Historically, there's Reverse ARP but nobody's using that. How to find the switch IP address based on MAC address? DNS translates (human-readable) host names to IP addresses, but without the changes above there's no IP connectivity. Trying some ARP workaround (configure a static ARP entry on the PC like 192.168.2.2 for the switch's MAC) won't help because you'd get the switch to receive the frame and extract the IP packet, but since the destination IP isn't local it'd be ignored (a layer-3 switch would even try to forward the packet).ĭNS doesn't help here. Alternatively, the switch could have another routable IP address and there's a router willing to forward in between. Either the PC needs to have an (additional) IP address within 169.254.0.0/16 or the switch needs to have an IP address within (assuming) 192.168.2.0/24. How would I be able to open an SSH connection with the device knowing only it's MAC adress? If you've configured the switch as a DHCP server then you will need to configure a static address. If you've configured the switch as a DHCP client then your DHCP server isn't working. This means that these two cannot talk to each other - they're both part of different IP networks and there's no router in betweeen (which isn't possible because of the unroutable .y address). On PC, the extra network adapter is configured as static 192.168.2.1.Ī switch with DHCP enabled is connected to 192.168.2.1 and if I login using the console (RS232) I see that it has .x source: link-local, MAC: xx:xx. ![]()
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