Delayed client IP acquisition on Cisco Switch

[an_ho]

Hi everyone,

I have encountered a strange problem - maybe someone here has an idea on how to troubleshoot this. My network layout looks like this:

                                          | Ubiquiti 24P unmanaged switch|

                                                           |

                                                           |

|Router/DHCP Server| --- | Cisco Catalyst 1000 16P|

                                                           |

                                                           |

                                          | Cisco Catalyst 1000 8|

Now when I plug a client into the Cisco C1000 16P switch, it takes about 10s for it to acquire an IP address from the DHCP server, but when I plug it into the unmanaged Ubiquiti switch it takes about 1-2s. Does anyone know why there is this time difference or how to troubleshoot? There is no port aggregation in place, STP is active on the cisco switches (everything else is basically on default setting, vlan1 active for everything).

Thanks!

[balaji.bandi · Accepted solution]

Looks like a port going  STP process....check access port are configured portfast 

Interface gi x/x  - where the PC connected.
spanning-tree portfast

 or post-show running-config- we can assist with what is wrong.

[Georg Pauwen]

Hello,

check which switch is the root for the Vlan your PC is connected to...

show spanning-tree vlan x