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We had a known cisco software bug on 3750 switch where if you enable DHCP ping check before it gives out address it causes chaos if more than 50 devices ask for DHCP at once.<br />
<br />
workaround is to disable the ping check - Done this.<br />
<br />
Ok, but now, in the event of switch failure/reboot the DHCp will allocate addresses from the beginning of the range again, potentially causing a DHCP conflict.<br />
<br />
I have heard there is the function to enable the switch(DHCP server) to write a bindings list to a TFTP server periodically, and in the event of a switch reboot, it checks for the binding list on start up before issuing any DHCP addresses.<br />
<br />
How do I acvieve this?<br />
<br />
Thanks
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We had a known cisco software bug on 3750 switch where if you enable DHCP ping check before it gives out address it causes chaos if more than 50 devices ask for DHCP at once.

workaround is to disable the ping check - Done this.

Ok, but now, in the event of switch failure/reboot the DHCp will allocate addresses from the beginning of the range again, potentially causing a DHCP conflict.

I have heard there is the function to enable the switch(DHCP server) to write a bindings list to a TFTP server periodically, and in the event of a switch reboot, it checks for the binding list on start up before issuing any DHCP addresses.

How do I acvieve this?

Thanks

How do I write log of DHCP bindings from cisco 3750 switch to a TFTP server periodically?

A router is a networking device that forwards data packets between computer networks. Routers perform the "traffic directing" functions on the Internet. The most familiar type of routers are home and small office cable or DSL routers that simply pass data, such as web pages, email, IM, and videos between computers and the Internet. More sophisticated routers, such as enterprise routers, connect large business or ISP networks up to the powerful core routers that forward data at high speed along the optical fiber lines of the Internet backbone. Though routers are typically dedicated hardware devices, use of software-based routers has grown increasingly common.

Routers

The Dynamic Host Configuration Protocol (DHCP) is an auto configuration protocol used on IP networks and an extension of the Bootstrap Protocol. DHCP allows for computers to be configured automatically to communicate with each other over an IP network without the need for manual setup by a network administrator. The implementation of DHCP relies on a DHCP server to hand out network configuration information to DHCP-capable clients that request an IP address (and other information required or useful in communicating with other devices on an IP network). In addition to an IP address, common configuration information served over DHCP includes a default gateway, subnet mask and DNS sever(s).

DHCP

A switch is a device that filters and forwards packets of data between LAN segments. Switches operate at the data link layer or the network layer of the Open Systems Interconnection (OSI) Reference Model and therefore support any packet protocol. LANs that use switches to join segments are called switched LANs or, in the case of Ethernet networks, switched Ethernet LANs. A hub is a connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports; when a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.