No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>

Reminder

To have a better experience, please upgrade your IE browser.

upgrade

DHCP Client Migrating from MA5200G Obtained a New Address After Being Reset Within the DHCP Lease

Publication Date:  2013-09-27 Views:  11 Downloads:  0
Issue Description
An ME60 running V600R002C02SPC700 substituted for an MA5200G to provide the DHCP relay function. After clients that migrated from the MA5200G were reset within the DHCP lease, obtained addresses were different from the address before the reset.
Handling Process

Possible causes include:

1. Mechanism difference

2. DHCP server fault

3. Client fault

The problem in this case was caused due to mechanism difference.

1. According to the related RFC description, a DHCP client that has obtained an IP address preferred to use the previously obtained address after being reset, and initiates a procedure to apply for extension of the IP address lease. If the application is approved, the lease extends. Otherwise, the client starts a new DHCP procedure to apply for an IP address. This means, within the lease, the client should be allocated the previously obtained address preferably as long as the address is not allocated to another client

2. Captured packets to analyze the problem.

After being reset, the client sent two discovery packets. Upon receiving the first packet, the ME60 released the client and sent a release message to the DCHP server to instruct it to release the address that had been allocated to the client. The ME60 transparently transmitted the second discovery packet to the DHCP server. Therefore, the DHCP server allocated a new IP address to the client.

3. Checked for difference in processing DHCP packets on the ME60 and MA5200G.

On MA5200G, dhcp through-packet was enabled, whereas on ME60 V600R002C02SPC700, the function was disabled by default, which caused the problem.
Root Cause
On MA5200G, dhcp through-packet was enabled, whereas on ME60 V600R002C02SPC700, the function was disabled by default, which caused the problem.
Solution
Enabled dhcp through-packet.
Suggestions
None

END