Strange DHCP REQUEST

munawar.zeeshan · ‎03-14-2008

i am getting this in my DHCP debug on a 3750 switch actiing as DHCP server.

17:30:55: DHCPD: unicasting BOOTREPLY to client 001c.23df.0cc8 (172.28.79.78).

17:30:57: DHCPD: DHCPINFORM received from client 0100.1b77.8e0b.33 (172.28.92.211).

17:30:57: DHCPD: Sending DHCPACK to client 0100.1b77.8e0b.33 (172.28.92.211).

17:30:57: DHCPD: unicasting BOOTREPLY to client 001b.778e.0b33 (172.28.92.211).

17:30:59: DHCPD: DHCPDISCOVER received from client 0152.4153.2000.166f.41b5.7500.0000.0000.

00 on interface Vlan100.

17:31:01: DHCPD: assigned IP address 172.28.92.220 to client 0152.4153.2000.166f.41b5.7500.

0000.0000.00.

17:31:01: DHCPD: Sending DHCPOFFER to client 0152.4153.2000.166f.41b5.7500.0000.0000.00 (17

2.28.92.220).

17:31:01: DHCPD: broadcasting BOOTREPLY to client 0016.6f41.b575.

17:31:03: DHCPD: DHCPDISCOVER received from client 0152.4153.2000.166f.41b5.7500.0000.0000.

00 on interface Vlan100.

17:31:03: DHCPD: Sending DHCPOFFER to client 0152.4153.2000.166f.41b5.7500.0000.0000.00 (17

2.28.92.220).

17:31:03: DHCPD: broadcasting BOOTREPLY to client 0016.6f41.b575.

17:31:11: DHCPD: DHCPDISCOVER received from client 0152.4153.2000.166f.41b5.7500.0000.0000.

00 on interface Vlan100.

17:31:11: DHCPD: Sending DHCPOFFER to client 0152.4153.2000.166f.41b5.7500.0000.0000.00 (17

2.28.92.220).

17:31:11: DHCPD: broadcasting BOOTREPLY

In DHCP binding i can see

172.28.92.220 004d.6173.7564.2020. Mar 02 1993 02:03 PM Automatic

5a61.6964.69

But the 172.28.92.220 address is not pingable.The MAC- address is of greater length then the usual norm.Can it be because of some Virus problem on client machines ?

Anyother solution ?

mchin345 · ‎03-20-2008

DHCP problems can arise due to a multitude of reasons. The most common reasons are configuration issues. However, many DHCP problems can be caused by software defects in operating systems, Network Interface Card (NIC) drivers, or DHCP/BootP Relay Agents running on routers. Due to the number of potentially problematic areas, a systematic approach to troubleshooting is required.

For more info

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a00800f0804.shtml#whereprobsoccur