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Will the Router be Rebooted frequently for Duplicate IP address ? %DHCPD-4-PING_CONFLICT: DHCP address conflict: server pinged

hadibaig05
Level 1
Level 1

Guys ,

I am receiving a alert %DHCPD-4-PING_CONFLICT: DHCP address conflict:  server pinged 172.16.42.15.  

I have a question will will the router and switch will reboot frequently for Duplicate IP  ? 

2 Accepted Solutions

Accepted Solutions

Leo Laohoo
Hall of Fame
Hall of Fame

Peter Paluch
Cisco Employee
Cisco Employee

Hello,

No, a router will not reboot because of a duplicate IP address. In fact, the message you are seeing means that the DHCP server running on your router wanted to assign an IP address that was already being used, and the DHCP server detected that, so this is not really a conflict at all because it has been prevented.

Is your router or a switch reloading? In normal operation, there is no reason for an automatic reload at all. In the case you are experiencing random reload, you should check the logs carefully if there are any messages recorded just prior to the reload that would point to the reason of the reload. Alternatively, it could be useful to connect to the console of the device and have a terminal software (HyperTerminal, PuTTY) record everything that shows up on the console to a file, so that we can analyze the behavior later.

Best regards,
Peter

View solution in original post

3 Replies 3

Leo Laohoo
Hall of Fame
Hall of Fame

No

Peter Paluch
Cisco Employee
Cisco Employee

Hello,

No, a router will not reboot because of a duplicate IP address. In fact, the message you are seeing means that the DHCP server running on your router wanted to assign an IP address that was already being used, and the DHCP server detected that, so this is not really a conflict at all because it has been prevented.

Is your router or a switch reloading? In normal operation, there is no reason for an automatic reload at all. In the case you are experiencing random reload, you should check the logs carefully if there are any messages recorded just prior to the reload that would point to the reason of the reload. Alternatively, it could be useful to connect to the console of the device and have a terminal software (HyperTerminal, PuTTY) record everything that shows up on the console to a file, so that we can analyze the behavior later.

Best regards,
Peter

Hi All,

Need some expertise here. Can someone explain the cause of the syslog error messages below. This causes my router to get a high cpu usage. 

Nov 26 21:48:33.863: %IP_VFR-3-OVERLAP_FRAGMENTS: GigabitEthernet0/0: from the host 39.165.151.49 destined to 116.50.137.23
Nov 26 21:48:33.863: %IP_VFR-3-OVERLAP_FRAGMENTS: GigabitEthernet0/0: from the host 39.165.151.49 destined to 116.50.137.23
Nov 26 21:48:33.863: %IP_VFR-3-OVERLAP_FRAGMENTS: GigabitEthernet0/0: from the host 39.165.151.49 destined to 116.50.137.23
Nov 26 21:48:34.723: %IP_VFR-3-OVERLAP_FRAGMENTS: GigabitEthernet0/0: from the host 39.165.151.49 destined to 116.50.137.23
Nov 26 21:48:34.727: %IP_VFR-3-OVERLAP_FRAGMENTS: GigabitEthernet0/0: from the host 39.165.151.49 destined to 116.50.137.23
Nov 26 21:48:34.791: %SEC-6-IPACCESSLOGP: list 100 denied tcp 183.232.96.107(0) -> 116.50.137.73(0), 119 packets
Nov 26 21:48:34.791: %SEC-6-IPACCESSLOGP: list 100 denied tcp 183.232.96.107(0) -> 116.50.137.61(0), 28 packets
Nov 26 21:48:35.219: %IP_VFR-3-OVERLAP_FRAGMENTS: GigabitEthernet0/0: from the host 39.165.151.49 destined to 116.50.137.23
Nov 26 21:48:35.219: %IP_VFR-3-OVEFRAGMENTS: GigabitEthernet0/0: from the host 39.165.151.49 destined to 116.50.137.23
Nov 26 21:48:36.083: %IP_VFR-3-OVERLAP_FRAGMENTS: GigabitEthernet0/0: from the host 39.165.151.49 destined to 116.50.137.23RLAP_FRAGMENTS: GigabitEthernet0/0: from the host 39.165.151.49 destined to 116.50.137.23
Nov 26 21:48:35.223: %IP_VFR-3-OVERLAP_FRAGMENTS: GigabitEthernet0/0: from the host 39.165.151.49 destined to 116.50.137.23
Nov 26 21:48:35.223: %IP_VFR-3-OVERLAP_
Nov 26 21:48:38.643: %IP_VFR-3-OVERLAP_FRAGMENTS: GigabitEthernet0/0: from the host 39.165.151.49 destined to 116.50.137.23
Nov 26 21:48:38.643: %IP_VFR-3-OVERLAP_FRAGMENTS: GigabitEthernet0/0: from the host 39.165.151.49 destined to 116.50.137.23
Nov 26 21:48:38.743: %IP_VFR-3-OVERLAP_FRAGMENTS: GigabitEthernet0/0: from the host 39.165.151.49 destined to 116.50.137.23
Nov 26 21:48:38.747: %IP_VFR-3-OVERLAP_FRAGMENTS: GigabitEthernet0/0: from the host 39.165.151.49 destined to 116.50.137.23
Nov 26 21:48:38.747: %IP_VFR-3-OVERLAP_FRAGMENTS: GigabitEthernet0/0: from the host 39.165.151.49 destined to 116.50.137.23
Nov 26 21:48:38.747: %IP_VFR-3-OVERLAP_FRAGMENTS: GigabitEthernet0/0: from the host 39.165.151.49 destined to 116.50.137.23

Thanks,

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