I did a DHCP client which work with about 70% of DHCP servers. But some of routers(DHCP servers) have a problem and send NAK for DHCP Reequest. Im not able found what ever do for rest of servers. What is bad or which parameter missing in Request packet.
I tried change some option, controll checksums etc. but no mistake found.
Zyxel router wrote in log:
2019 -05 -09 T14:58:40 daemon notice syslog: Receive DHCP DISCOVER from 00:4F:49:0D:FF:FF 99
2019 -05 -09 T14:58:40 daemon notice syslog: Send DHCP OFFER to 00:4F:49:0D:FF:FF with IP 99
2019 -05 -09 T14:58:40 daemon notice syslog: Receive DHCP REQUEST from 00:4F:49:0D:FF:FF 98
2019 -05 -09 T14:58:40 daemon notice syslog: Send DHCP NACK to 00:4F:49:0D:FF:FF 90
Screenshots from wireshark:
Any idea where is a problem for router?
