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What happens if DHCP client fails to obtain IP address?
If not, the server responds to the DHCPRequest with a NACK packet. If the client sending the DHCPRequest is requesting an address that appears to be on the same subnet but was actually assigned with a different subnet mask, the DHCP server will remain silent and the client will fail to obtain a valid IP address for the new subnet.
What happens if one of the DHCP servers goes offline?
Both servers manage the same pool of addresses, but only one of the servers is active at any given time. Should the active server fail or go offline (for example, for routine maintenance), then the other server will automatically come online to take over the first server’s load.
What is the IP address of the DHCP server?
For example, assume the DHCP client obtains address 172.17.3.x with a subnet mask of 255.255.255.0, and the client is moved to a new segment where the address of the DHCP server is 172.17.1.x with a subnet mask of 255.255.0.0.
Why does the DHCP server remain silent if the address is on the same subnet?
If the address appears to be on the same subnet, the DHCP server will remain silent even if the address isn’t in the range of its pool of addresses. The DHCP server assumes that the address was assigned by another DHCP server on the same segment if it’s not from its own pool.
What happens if the DHCP address is not on the same subnet?
If it originated from the local segment, the DHCP server compares the requested address to the IP address and subnet mask belonging to the local interface that received the request. If the address appears to be on the same subnet, the DHCP server will remain silent even if the address isn’t in the range of its pool of addresses.
Why does DHCP handler not rerun after reboot?
Rerun dhcp handler 2017/12/11 10:44:11.951230 INFO Start env monitor service. also the errors are gone after the reboot. we have checked the yum log also we could see the that there was no package removed/installed is this something to do with the wireserver. waagent was not able to reach the wireserver and it failed.
What happens when DHCP server sends a NACK packet?
If a DHCP server sends a NACK packet in response to the DHCPRequest, the client goes into the Discover cycle; it also requests the previously assigned address in the DHCPDiscover packet.
How to renew IP with dhclient on different interfaces?
Two answers suggested doing dhclient -r eth0 eth1 && dhclient eth0 eth1 This, indeed, limits the broadcast calls to these interfaces. But the first DHCP server to answer will be the only one used, hence resulting in a new IP on a single interface and not both.
Why is dhclient making DHCP requests on a static IP?
The older system doesn’t have a ‘dhclient’ process running. Sorry if this is basic stuff, there are some holes in my Linux knowledge. dhclient process does not stop when you change /etc/network/interfaces file from dhcp to static type. see https://askubuntu.com/questions/459140/why-dhclient-is-still-running-when-i-choose-static-ip for more info