Brocade Communications Systems Layer 3 Routing Configuration ICX 6650 User Manual
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Brocade ICX 6650 Layer 3 Routing Configuration Guide
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Configuring IP parameters – Layer 3 Switches
3. If the device has a dynamic address, the device asks the DHCP server to validate that address.
If the server does not respond, the device will continue to use the existing address until the
lease expires. If the server responds, and the IP address is outside of the DHCP address pool
or has been leased to another device, it is automatically rejected, and the device receives a
new IP address from the server. If the existing address is valid, the lease continues.
NOTE
The lease time interval is configured on the DHCP server, not on the client device. The ip
dhcp-client lease command is set by the system, and is non-operational to a user.
4. If the existing address is static, the device keeps it and the DHCP Client process is ended.
5. For a leased IP address, when the lease interval reaches the renewal point, the device
requests a renewal from the DHCP server:
•
If the device is able to contact the DHCP server at the renewal point in the lease, the DHCP
server extends the lease. This process can continue indefinitely.
•
If the device is unable to reach the DHCP server after four attempts, it continues to use the
existing IP address until the lease expires. When the lease expires, the dynamic IP address
is removed and the device contacts the DHCP server for a new address. If the device is still
unable to contact the DHCP server after four attempts, the process is ended.
The TFTP Flash image download and update step
NOTE
This process only occurs when the client device reboots, or when DHCP-client has been disabled and
then re-enabled.
Once a lease is obtained from the server (described in
“Validate the IP address and lease
on page 83), the device compares the filename of the requested flash image with the
image stored in flash.
•
If the .bin filenames match, then the DHCP client skips the flash image download. If
auto-configuration is enabled, the DHCP client proceeds with downloading the configuration
files as described in
“The TFTP configuration download and update step”
.
•
If the .bin filenames are different, then the DHCP client downloads the new image from a TFTP
server, then writes the downloaded image to flash.
The code determines which flash (i.e., primary or secondary) to use based on how the device is
booted. Once the flash is updated with the newer flash image, the device is reloaded If
auto-configuration is enabled, the DHCP client then proceeds to download the configuration
files described in
“The TFTP configuration download and update step”
.
The TFTP configuration download and update step
NOTE
This process only occurs when the client device reboots, or when Auto-Configuration has been
disabled and then re-enabled.