Server 2016 (only) DHCP Service fails to get addresses to helper-address networks

asked in server general suggested migrate forum.

replaced bunch of 2008r2 servers 2016, , migrated dhcp setups.

work fine of time, have @ least 2 (of eight) having troubles on recurring basis. clients stop getting addresses, clients on other subnets getting them through helper addresses in local l3 switches.

when occurs (about once every 2-14 days randomly) can see addresses handed out , registered in dns in dhcp log, client requests them again, , again, , again.  there no errors logged @ all, in events or dhcp log.

when occurs, cannot restart dhcp service, not respond (but running still trying hand out addresses; speculate may hung volume of requests, though bit lame 1 think still respond eventually). 

when occurs, continue hand out local addresses, i.e. on subnet nic is.

reboot of server fixes it. no change being made l3 switch (cisco) during time, not think issue in switch (unless somehow server reboot can trigger change there). 

again - dhcp working fine on local subnet, , thinks working fine according log, during these events; response packets either wrong, or not getting forwarded properly.  and when happens 1 cannot restart dhcp, reboot fixes it.

2016 servers datacenter flavor, , hyperv guests on 2012 physical server single nic.

again, working fine 2008r2 servers.  and works (with high volume - these student wireless devices) days @ time.  the 2 servers not working not on same hyperv server , separated wide area network, i.e. failing sites similar share no physical infrastructure.

there no firewalls between dhcp server , requesting devices.  the requesting devices connect via aerohive access points, though true before, , no changes made there, nor changes made cisco l3 switches. change during time server change.  the server not upgraded -- clean install, followed migration (using microsoft tools) of dhcp database.  we not (yet) using failover features of new dhcp server, it's plain, vanilla setup.  we have @ least 6 other 2016 servers working fine dhcp, put in same time, same configuration checklist , on similar hyperv configurations.  all dhcp servers domain controllers , dns servers.  there no signs of ad/dns issues before, during or after. attempts assign ip addresses register in dns, not reach clients.

have not seen specific 2016 might apply far in searching.

@ helpful. thank you.

linwood

hi,

suppose dhcpack packet blocked  that  doesn't reach clients.

suggest download network monitor capture packet.

microsoft network monitor

https://www.microsoft.com/en-sg/download/details.aspx?id=4865


best regards,

frank

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Windows Server  >  IPAM, DHCP, DNS