cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Announcements

194
Views
0
Helpful
8
Replies
Beginner

DHCP Stops responding after a couple days

Hello Community, im having trouble getting DHCP to work on a L3 Core Cisco switch, it works properly but after a few days it stops responding, then i proceed to delete the dhcp pool and create it again solving the problem but only for a few days, any pointers or recommendation on what could it be? any help is greatly appreciated! many thanks!

 

this is the wireshark packet capture:

 

Frame 1: 342 bytes on wire (2736 bits), 342 bytes captured (2736 bits) on interface 0
Interface id: 0 (\Device\NPF_{8117FD5C-52CA-4B45-8137-0790F5C325D8})
Interface name: \Device\NPF_{8117FD5C-52CA-4B45-8137-0790F5C325D8}
Interface description: Wi-Fi
Encapsulation type: Ethernet (1)
Arrival Time: Aug 15, 2019 10:16:30.666225000 Central Daylight Time (Mexico)
[Time shift for this packet: 0.000000000 seconds]
Epoch Time: 1565882190.666225000 seconds
[Time delta from previous captured frame: 0.000000000 seconds]
[Time delta from previous displayed frame: 0.000000000 seconds]
[Time since reference or first frame: 0.000000000 seconds]
Frame Number: 1
Frame Length: 342 bytes (2736 bits)
Capture Length: 342 bytes (2736 bits)
[Frame is marked: False]
[Frame is ignored: False]
[Protocols in frame: eth:ethertype:ip:udp:dhcp]
[Coloring Rule Name: UDP]
[Coloring Rule String: udp]
Ethernet II, Src: IntelCor_dc:59:38 (a8:6d:aa:dc:59:38), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Destination: Broadcast (ff:ff:ff:ff:ff:ff)
Address: Broadcast (ff:ff:ff:ff:ff:ff)
.... ..1. .... .... .... .... = LG bit: Locally administered address (this is NOT the factory default)
.... ...1 .... .... .... .... = IG bit: Group address (multicast/broadcast)
Source: IntelCor_dc:59:38 (a8:6d:aa:dc:59:38)
Address: IntelCor_dc:59:38 (a8:6d:aa:dc:59:38)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Type: IPv4 (0x0800)
Internet Protocol Version 4, Src: 0.0.0.0, Dst: 255.255.255.255
0100 .... = Version: 4
.... 0101 = Header Length: 20 bytes (5)
Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT)
Total Length: 328
Identification: 0x7275 (29301)
Flags: 0x0000
Time to live: 128
Protocol: UDP (17)
Header checksum: 0xc730 [validation disabled]
[Header checksum status: Unverified]
Source: 0.0.0.0
Destination: 255.255.255.255
User Datagram Protocol, Src Port: 68, Dst Port: 67
Source Port: 68
Destination Port: 67
Length: 308
Checksum: 0xcf6e [unverified]
[Checksum Status: Unverified]
[Stream index: 0]
[Timestamps]
Dynamic Host Configuration Protocol (Discover)
Message type: Boot Request (1)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0x6923e70d
Seconds elapsed: 0
Bootp flags: 0x0000 (Unicast)
Client IP address: 0.0.0.0
Your (client) IP address: 0.0.0.0
Next server IP address: 0.0.0.0
Relay agent IP address: 0.0.0.0
Client MAC address: IntelCor_dc:59:38 (a8:6d:aa:dc:59:38)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type (Discover)
Length: 1
DHCP: Discover (1)
Option: (61) Client identifier
Length: 7
Hardware type: Ethernet (0x01)
Client MAC address: IntelCor_dc:59:38 (a8:6d:aa:dc:59:38)
Option: (12) Host Name
Length: 15
Host Name: DESKTOP-PROG09H
Option: (60) Vendor class identifier
Length: 8
Vendor class identifier: MSFT 5.0
Option: (55) Parameter Request List
Length: 14
Parameter Request List Item: (1) Subnet Mask
Parameter Request List Item: (3) Router
Parameter Request List Item: (6) Domain Name Server
Parameter Request List Item: (15) Domain Name
Parameter Request List Item: (31) Perform Router Discover
Parameter Request List Item: (33) Static Route
Parameter Request List Item: (43) Vendor-Specific Information
Parameter Request List Item: (44) NetBIOS over TCP/IP Name Server
Parameter Request List Item: (46) NetBIOS over TCP/IP Node Type
Parameter Request List Item: (47) NetBIOS over TCP/IP Scope
Parameter Request List Item: (119) Domain Search
Parameter Request List Item: (121) Classless Static Route
Parameter Request List Item: (249) Private/Classless Static Route (Microsoft)
Parameter Request List Item: (252) Private/Proxy autodiscovery
Option: (255) End
Option End: 255
Padding: 00000000

 

ill also attach a capture of when it works properly for reference:

 

Frame 22255: 370 bytes on wire (2960 bits), 370 bytes captured (2960 bits) on interface 0
Interface id: 0 (\Device\NPF_{8117FD5C-52CA-4B45-8137-0790F5C325D8})
Interface name: \Device\NPF_{8117FD5C-52CA-4B45-8137-0790F5C325D8}
Interface description: Wi-Fi
Encapsulation type: Ethernet (1)
Arrival Time: Aug 15, 2019 10:37:44.883231000 Central Daylight Time (Mexico)
[Time shift for this packet: 0.000000000 seconds]
Epoch Time: 1565883464.883231000 seconds
[Time delta from previous captured frame: 0.038054000 seconds]
[Time delta from previous displayed frame: 1.061145000 seconds]
[Time since reference or first frame: 1274.217006000 seconds]
Frame Number: 22255
Frame Length: 370 bytes (2960 bits)
Capture Length: 370 bytes (2960 bits)
[Frame is marked: False]
[Frame is ignored: False]
[Protocols in frame: eth:ethertype:ip:udp:dhcp]
[Coloring Rule Name: UDP]
[Coloring Rule String: udp]
Ethernet II, Src: IntelCor_dc:59:38 (a8:6d:aa:dc:59:38), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Destination: Broadcast (ff:ff:ff:ff:ff:ff)
Address: Broadcast (ff:ff:ff:ff:ff:ff)
.... ..1. .... .... .... .... = LG bit: Locally administered address (this is NOT the factory default)
.... ...1 .... .... .... .... = IG bit: Group address (multicast/broadcast)
Source: IntelCor_dc:59:38 (a8:6d:aa:dc:59:38)
Address: IntelCor_dc:59:38 (a8:6d:aa:dc:59:38)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Type: IPv4 (0x0800)
Internet Protocol Version 4, Src: 0.0.0.0, Dst: 255.255.255.255
0100 .... = Version: 4
.... 0101 = Header Length: 20 bytes (5)
Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT)
Total Length: 356
Identification: 0x7299 (29337)
Flags: 0x0000
Time to live: 128
Protocol: UDP (17)
Header checksum: 0xc6f0 [validation disabled]
[Header checksum status: Unverified]
Source: 0.0.0.0
Destination: 255.255.255.255
User Datagram Protocol, Src Port: 68, Dst Port: 67
Source Port: 68
Destination Port: 67
Length: 336
Checksum: 0x41fd [unverified]
[Checksum Status: Unverified]
[Stream index: 0]
[Timestamps]
Dynamic Host Configuration Protocol (Request)
Message type: Boot Request (1)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0xd2626714
Seconds elapsed: 10
Bootp flags: 0x8000, Broadcast flag (Broadcast)
Client IP address: 0.0.0.0
Your (client) IP address: 0.0.0.0
Next server IP address: 0.0.0.0
Relay agent IP address: 0.0.0.0
Client MAC address: IntelCor_dc:59:38 (a8:6d:aa:dc:59:38)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type (Request)
Length: 1
DHCP: Request (3)
Option: (61) Client identifier
Length: 7
Hardware type: Ethernet (0x01)
Client MAC address: IntelCor_dc:59:38 (a8:6d:aa:dc:59:38)
Option: (50) Requested IP Address (192.168.100.102)
Length: 4
Requested IP Address: 192.168.100.102
Option: (54) DHCP Server Identifier (192.168.100.1)
Length: 4
DHCP Server Identifier: 192.168.100.1
Option: (12) Host Name
Length: 15
Host Name: DESKTOP-PROG09H
Option: (81) Client Fully Qualified Domain Name
Length: 18
Flags: 0x00
A-RR result: 0
PTR-RR result: 0
Client name: DESKTOP-PROG09H
Option: (60) Vendor class identifier
Length: 8
Vendor class identifier: MSFT 5.0
Option: (55) Parameter Request List
Length: 14
Parameter Request List Item: (1) Subnet Mask
Parameter Request List Item: (3) Router
Parameter Request List Item: (6) Domain Name Server
Parameter Request List Item: (15) Domain Name
Parameter Request List Item: (31) Perform Router Discover
Parameter Request List Item: (33) Static Route
Parameter Request List Item: (43) Vendor-Specific Information
Parameter Request List Item: (44) NetBIOS over TCP/IP Name Server
Parameter Request List Item: (46) NetBIOS over TCP/IP Node Type
Parameter Request List Item: (47) NetBIOS over TCP/IP Scope
Parameter Request List Item: (119) Domain Search
Parameter Request List Item: (121) Classless Static Route
Parameter Request List Item: (249) Private/Classless Static Route (Microsoft)
Parameter Request List Item: (252) Private/Proxy autodiscovery
Option: (255) End
Option End: 255

 

best regards!

 

EDIT: attached the wrong packet

8 REPLIES 8
Rising star

Re: DHCP Stops responding after a couple days

 

 - Could be a software bug, check current release and or consider testing with more recent versions, if applicable. 

 M.

Beginner

Re: DHCP Stops responding after a couple days

will try and keep posted, thanks for sharing!

Participant

Re: DHCP Stops responding after a couple days

have you run debugs on dhcp on your core device?

Beginner

Re: DHCP Stops responding after a couple days

will try and post back, thanks for sharing

VIP Mentor

Re: DHCP Stops responding after a couple days

Hello,

 

post the output of 'show ver'.

 

Does it also start to work again if you disable/enable the DHCP service ?

 

CoreSwitch(config)#no service dhcp

CoreSwitch(config)#service dhcp

Hall of Fame Master

Re: DHCP Stops responding after a couple days

Is it possible that your DHCP pool assigns a very long lease time (or even perhaps infinite)? This could lead to all addresses being used and no addresses available for assignment.

 

HTH

 

Rick

Highlighted
Beginner

Re: DHCP Stops responding after a couple days

ive tried 7 and 30 day leases, also ipconfig /renew works on windows when dhcp is up

Beginner

Re: DHCP Stops responding after a couple days

will try and post back the outcome and "show ver" thanks!

CreatePlease to create content
Content for Community-Ad
July's Community Spotlight Awards