ASAK Mohammed,
Assuming your topology:
PC-----Access-Switch---IP DHCP --------Core Switch(DHCP Server).
1- PC getting IP address without any issue from the core switch.
2- Were r u trying to ping were you are seeing the slow reply? Does it respond to GW without any issue?
3- Is this issue with all the systems? IS the problem seen pinging the devices each other in the same vlan?
4- Did you check if there are any CPU/STP/ Link utilization issue on the switches?
Please brief us so that we able to help you out?
HTH
REgards
Inayath
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